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EXPERIMENTAL

PHARMACOLOGY

BY

DENNIS E. JACKSON, PH.D., M.D.

ASSOCIATE PROFESSOR OF PHARMACOLOGY, WASHINGTON UNIVERSITY
MEDICAL SCHOOL, ST. LOUIS.

WITH THREE HUNDRED NINETY ORIGINAL ILLUSTRA-
TIONS INCLUDING TWENTY-FOUR FULL-PAGE

COLOR PLATES

.

ST. LOUIS
C. V. MOSBY COMPANY

1917

COPYRIGHT, 1917, BY C. V. MOSBY COMPANY

Press of

C. V. Mosby Company
St. Louis

PREFACE.

For several years the writer has had a growing convic-
tion that the teaching of pharmacology might be greatly
facilitated, and rendered much more effective and compre-
hensive, if each student could have in his own hands a
laboratory manual giving exact, specific, detailed directions
for carrying out most of the experiments which he will
be called upon to perform in the study of this most inter-
esting, vital and complex subject. The small number of
manuals of this character which heretofore have appeared,
in this field may be most strikingly compared with the very
large number of laboratory manuals which have been pub-
lished on such subjects as chemistry, botany, physics,
zoology, etc. And the thoughtful teacher might be at once
inclined to ask himself whether or not the general scope
and character of the work done in these various experi-
mental fields may not have been to some extent indicated
by the number and character of experimental manuals de-
voted to these subjects. In consideration of these points
the author has therefore ventured to hope that in present-
ing this manual of experimental pharmacology to teachers
and students, some small amount of good may be accom-
plished.

My especial thanks are due to the publishers, who have
rendered every assistance they could in the progress of
this work; to Mr. Paul Knabe, who has faithfully devoted
much time and labor to the proof reading, the arrangement
of the illustrations, and the printing of the book; and to
Mr. Paul P. Halleck, who in making the drawings contained
herein has given me the advantage both of his extensive
experience as an artist, and of his special training as a
physician. I am deeply indebted to Mr. John A. Higgins,

4 PREFACE

who for seven years has faithfully assisted me in per-
forming most of the experiments from which the tracings
illustrated in this book have been mainly derived.

D. E. J.

Pharmacological Laboratory,
Washington University Medical School.

CONTENTS.
PART I.

PRELIMINARY EXERCISE.

PAGE
Assignment of Tables and Permanent Apparatus . . 33

EXPERIMENTS.

I. Ether. (Action on the Central Nervous System. Cerebrum.) . . 53
Chloroform. (Action on the Central Nervous System. Optic

Lobes.) 55

Ether, Ethyl Chloride, Chloroform, Ethyl Bromide. (Irritability

and Conductivity of Nerve.) 57

Ethyl Chloride. (Local Anesthesia.) 64

II. Ether. (Action on the Heart. Dissection for the Vagus Nerve

in the Frog.) 65

Chloroform. (Action on the Frog's Heart.) 70

Chloroform. (Action on Lymph Hearts.) 70

III. Turtle: Vagus Dissection. (Action of Ether on the Heart.) . . 71
Chloroform. (Action on the Turtle's Heart.) 76

IV. Ether, Chloroform, Ethyl Bromide. (Dog: Respiration, Blood-

pressure, Cervical Vagi, and Sympathetics.) 77

Anesthetization of the Animal 77

Insertion of Tracheal and Carotid Cannulas; Isolation of Vagi

and External Jugular Vein 85

Insertion of Femoral Injecting Cannula ; Dissection of Femoral

Artery and Vein and Saphenous Nerve 93

Recording Blood-pressure 96

Recording Respiration . 97

Adjustment of Writing Points 98

Other Methods of Recording Respiration 98

Beginning of the Records 99

V. Ether, Chloroform, Ethyl Bromide. (Dog: Motor Areas, Blood-
pressure, Blood, Heart.) 103

Dissection of Pulmonary Artery and Vein 112

VI. Nitrous Oxide, Carbon Dioxide, Oxygen. (Frog: Central Nervous

System.) 113

VII. Nitrous Oxide, Ethyl Chloride, Carbon Dioxide, Increased Atmos-
pheric Pressure, (Decreased Atmospheric Pressure.) (Frog,

Guinea Pig, Rat, Kitten, or Pup.) 117

Paul Bert's Experiment 120

6 CONTENTS

PAGE

VIII. The Closed Method of Anesthesia. For Ether, Chloroform,
Ethyl Chloride, Ethyl Bromide, (Nitrous Oxide), "Somno-
form," etc., with Oxygen, .Student Method. (Dogs or

Cats.) 1-21

IX. Intratracheal Insufflation 129

X. Alcohol. (Frog: Central Nervous System, Heart and Vago-

Sympathetic Nerve.) 133

XL Alcohol. (Turtle: Heart and Vagus Nerve.) 135

XII. Ethyl Alcohol, Brandy, Whiskey, Wine, Methyl Alcohol, Amyl

Alcohol. (Dog: Blood-pressure, Respiration, Esophagus.) 136

XIII. Whiskey or Brandy. (Reaction Time.) 144

XIV. Alcohol, Whiskey, Brandy, Wine. (Dog or Cat: Myocardio-

graphic Tracings, Cardiac .Sympathetic Nerves.) .... 147

XV. Antiseptic Action of Alcohol 157

XVI. Alcohol, Brandy, Urethane, Chloral. (Dog: Blood-pressure,

Respiration, Cerebrospinal Fluid, Kidney or Spleen.) . . 158
XVII. Chloral Hydrate, Urethane, Paraldehyde, Chloretone. (Frogs:

Central Nervous System.) 168

XVIII. Chloral Hydrate. (Action on the Frog's Heart.) .... 169
XIX. Chloral Hydrate. (Frog: Retinal Circulation With the

Ophthalmoscope.) 169

XX. Chloral Hydrate, Adrenaline. (Turtle's Heart.) 172

XXI. Chloral Hydrate and Alkalis 172

XXII. Morphine. (Frog: Central Nervous System.) 172

XXIII. Thebaine, Codeine. (Frog: Central Nervous System.) . . . 173

XXIV. Morphine. (Chemical Test -for Morphine.) 173

XXV. Morphine. (Dog: Respiration, Excretion, Pupils, Central Ner-
vous System, General Symptoms.) 175

XXVI. Fehling's Test for Reducing Bodies 176

XXVII. Morphine. (Cat: General Symptoms, Central Nervous

System.) 177

XXVIII. Morphine, Codeine. (Dog: Respiration, Blood-pressure, Oxy-
gen Consumption, Urine.) 177

XXIX. Morphine, Codeine, Pantopon, Heroine, Peronine, Dionine, Nar-

cotine or Thebaine. (Spinal Dog: Bronchioles.) . . . 194
XXX. Heroine or Codeine. (Spinal Dog: Blood-pressure, Lung Vol-
ume and Bladder Contractions.) 206

XXXI. Strychnine. (Frog: Action on the Cord.) 217

XXXII. Strychnine. (Frog: Heart and Vago-sympathetic Nerve.) . 220

XXXIII. Strychnine. (Turtle: Heart and Vagus Nerve.) 220

XXXIV. Strychnine. (Dog: Blood-pressure, Respiration, and Kidney,

Spleen or Intestinal Loop.) 222

XXXV. Strychnine. (Ether, Morphine, Chloral Hydrate.) (Dog:
Blood-pressure, Respiration, Oxygen Consumption, Air Em-
bolism.) 226

CONTENTS 7

PAGE

XXXVI. Strychnine. (Student: Reaction Time.) 230

XXXVII. Picrotoxine. (Frog: Action on Medulla and Cord.) ... 231
XXXVIII. Picrotoxine, Chloretone. (Dog: Blood-pressure, Respiration

and Kidney, Spleen or Intestinal Loop Volume.) . . 233

XXXIX. Hydrastine. (Frog: Spinal Cord.) 238

XL. Hydrastine. (Frog: Heart and Vagus Nerve.) 240

XLI. Hydrastine. (Turtle: Heart and Vagus Nerve.) .... 241

XLII. Caffeine.' (Frog: Central Nervous System, Muscles.) . . 241

XLIII. Caffeine. (Frog: Muscle and Nerve.) 243

XLIV. Caffeine. (Frog: Heart and Vagus Nerve.) 244

XLV. Caffeine. (Turtle: Heart and Vagus Nerve.) 244

XLVI. Caffeine. (Man: Reaction Time.) 244

XLVII. Caffeine. (Frog: Muscular Work.) 245

XLVIII. Caffeine. (Rabbit: Diuresis, Cervical Nerves, Depressor.) . 247
XLIX. Caffeine, Sodium Sulphate. (Dog: Blood-pressure, Diuresis,

Respiration, Sciatic Nerve.) 240

L. Diuretine, (Sodium-theobromine-salicylate), Agurine, (So-
dium-theobromine-acetate). (Rabbit: Diuresis and Res-
piration.) 253

LI. Urea, S. A. Matthews' Solution, or Saline Diuretics. (Rab-
bit or Cat: Diuresis.) 254

LII. Curara. (Frog: General Action, Claud Bernard's Experi-
ment.) 255

LIII. Curara. (Frog: Heart and Vago-sympathetie Nerve.) . . 257

LIV. Curara. (Turtle: Heart and Vagus Nerve.) 257

LV. Curara, Strychnine. (Dog or Cat: Blood-pressure, Respira-
tion, Urine, Sciatic Nerve. Dog: Salivary Ducts and

Nerves.) 257

Dog 250

LVI. Coniine. (Frog: Heart and Vagus Nerve.) 260

LVII. Coniine. (Turtle: Heart and Vagus Nerve, Lungs and Sym-
pathetic Nerves.) 260

LVIII. Coniine. (Dog: Blood-pressure, Respiration, Salivary Glands

and Kidney, Spleen or Intestinal Loop.) 265

LIX. Atropine. (Frog: Heart and Vagus Nerve.) L'tis

LX. Atropine. (Frog: Muscle and Nerve) 260

LXI. Atropine. (Turtle: Heart and Vagus Nerve.) 2(!'.i

LXII. Atropine. (Cat, Guinea Pig, Rat, Dog, Pigeon, or Chicken:

Pupil.) 260

LXIII. Atropine. (Dog, Cat or Rabbit : Blood-pressure, Respiration,
Heart and Vagus Nerve, Dog, Salivary Secretion and

Chorda Tympanl, Sweat Nerves, Pancreatic Secretion.) 270

LXIV. Scopolamine. (Frog: General Symptoms.) 273

LXV. Pilocarpine, Atropiue. (Frog: Heart and Vagus Nerve.) . 2"::
LXVI. Pilocarpine or Arecoline and Atropine. (Frog: Retinal Cir-
culation.) 274

8 CONTENTS

PAGE

LXVII. Pilocarpine or Arecolinc and Atropiue. (Dog, Cat, Rabbit,

and Pigeon or Chicken: Pupil.) 275

LXVIII. Pilocarpine, Atropine. (Dog: Blood-pressure, Respiration,

Salivary and Pancreatic Secretions.) 275

LXIX. Pilocarpine, Arecoline, Adrenaline, Atropine, and Barium.

(Dog: Bladder, Intestine, Respiration, Blood-pressure.) 278
LXX. Pilocarpine, Adrenaline, Arecoline, Atropine, Barium.

(Spinal Dog: Blood-pressure and Bronchioles.) . . 287

LXXI. Nicotine. (Frog: General Symptoms.) 300

LXXII. Nicotine. (Frog: Heart and Vagus Nerve.) 300

LXXIII. Nicotine. (Turtle: Heart and Vagus Nerve.) .... 301

LXXIV. Nicotine. (Turtle: Lungs.) 302

LXXV. Nicotine, Arecoline, Atropine. (Dog: Blood-pressure, Res-
piration, Limb Volume, Intestinal Contraction.) . . . 304
LXXVI. Nicotine, Adrenaline, Pilocarpine, Atropine. (Dog: Blood-
pressure, Intraocular Pressure, Respiration and Kidney,

Spleen or Intestinal Loop Volume.) 307

LXXVII. Nicotine, Adrenaline, Barium. (Dog: Pulmonary Blood-
pressure, Carotid Pressure.) 310

LXXVIII. Nicotine, Pilocarpine, Atropine. (Dog: Intraocular Nerves,
Salivary Glands, Oxygen Consumption, Blood-pressure

and Respiration.) 318

LXXIX. Lobeline. (Frog or Turtle: Heart and Inhibitory Nerves.) 322
LXXX. Lobeline, Pilocarpine. (Turtle: Lung Tracings.) . . . 322
LXXXI. Lobeline, Adrenaline, Pilocarpine, Tetramethylammonium
chloride. (Dog: Bladder Contraction, Blood-pressure,

Respiration, Pupil.) 325

LXXXII. Lobeline, Nicotine, Pilocarpine. ( Guinea Pig, Cat, Dog, or

Rabbit; Uterus Strip.) 332

LXXXIII. Adrenaline, Lobeline, Nicotine, Pilocarpine, Atropine.
(Guinea Pig, Rabbit, Dog, Cat, Frog: Intestinal Seg-
ment.) 334

LXXXIV. Muscarine, Atropine. (Turtle: Lung Tracings.) .... 336

LXXXV. Physostigmine. (Frog: Heart Tracing.) 337

LXXXVI. Physostigmine, Atropine, (Sodium Nitrite). (Frog: Stom-
ach Ring.) 337

LXXXVII. Physostigmine. (Turtle: Heart Tracing. ) 338

LXXXVIII. Physostigmine, (Adrenaline, Atropine). (Turtle: Lung

Tracing.) 338

LXXXIX. Physostigmine, Hyoscine, Adrenaline, (Trimethylamine )
(Dog: Respiration, Blood-pressure, Intestinal Contrac-
tions.) 339

XC. Adrenaline, Sodium Nitrite, Barium Chloride. (Dog, Cat

or Rabbit: Perfusion of Kidney.) 342

CONTENTS 9

PAGE

XCI. Physostigmine, Atropine, (Heroine), Adrenaline. (Spinal Dog
or Cat : Bronchioles, Blood-pressure, and Bladder Contrac-
tions.) , . . ." 346

XCII. Cocaine. (Frog: Central Nervous System.) 350

XCIII. Cocaine, Physostigmine. (Rabbit, Cat, Dog, Pigeon, Sparrow.

Chicken, Rat : Action on Pupil.) 350

XCIV. Cocaine, Novocaine. (Local Anesthetic Action.) 351

XCV. Cocaine. (Frog or Turtle: Heart Tracings.) 351

XCVI. Cocaine. (Frog: Action on Muscular Work.) 352

XCVII. Cocaine, Novocaine, Barium, Adrenaline. (Dog or Cat: Res-
piration, Blood-pressure, Intraocular Pressure, Local Vascu-
lar Action and Intestinal Contractions.) 353

XCVIII. Novocaiue. (Dog: Spinal Anesthesia.) 356

XCIX. Ergot. (Rooster: Action on Comb.) 360

C. Ergot. (Frog: Capillary Circulation.) . 361

CI. Tyramine. (Frog: Capillary Circulation.) 363

CII. Ergamine. (Turtle: Lung Tracing.) 363

CHI. Ergotoxine, Ergamine, Adrenaline, Barium. (Dog. or Cat:
Blood-pressure, Respiration, Uterine Contractions Bar-
hour's Method.) 363

CIV. Ergamine, Adrenaline, Tyramine, (Codeine or Heroine). (Dog:

Blood-pressure, Pulmonary Blood-pressure, Respiration.) . 369
CV. Ergamine, Adrenaline (or Hordenine), Atropine. (Spinal Dog,

or Cat: Bronchioles.) 373

CVI. Ergotoxine, Ergamine. (Cat, Guinea Pig, Dog, Rabbit: Uterine

Strip.) 380

CVII. Ergot. (Cat: Action on Uterus.) 3S1

CVIII. Pituitrin, Ergamine, Adrenaline. (Dog, Cat. or Rabbit: Uter-
ine Contractions, Blood-pressure.) 382

CIX. Pituitrin, Ergamine, Levulose, Adrenaline. (Dog: Thoracic

Duct, Blood-pressure, Bladder Contractions, Respiration.) 38-4

CX. Pituitrin. (Frog: Capillary Circulation.) 387

CXI. Pituitrin. (Frog or Turtle: Heart Tracing.) -. 388

CXII. Pituitrin. (Turtle: Lung Tracing.) '388

CXIII. Pituitrin. (Guinea Pig, Cat, Dog, Rabbit : Uterine Strip.) . 390
CXIV. Pituitary Extract, Adrenaline, Atropine, Barium (Dog: Bron-
chial Contraction.) 391

CXV. Pituitrin, Adrenaline, Aconitine. (Dog: Urine Secretion, In-
testinal Contractions, Blood-pressure, and Respiration.) . .".92
CXVI. Pituitrin, Adrenaline, Vanadium. (Dog: Pulmonary Blood-
pressure.) 394

CXVII. Dissection of the Eye. Its Anatomy and Pharmacology . . . 394
CXVIII. Amyl Nitrite. (Student: Plethysmographic Record, General

Action.) 397

10 CONTENTS

PAGE

CXIX. Amyl Nitrite. (Student: Pulse Tracing.) 399

CXX. Amyl Nitrite. (Student: Corpuscles in Retinal Vessels.) 400

CXXI. Amyl Nitrite. (Student: Retinal Blood Vessels.) ... 401

CXXII. Amyl Nitrite. (Student: Effect on Vision.) 403

CXXIII. Amyl Nitrite, Nitroglycerine, Sodium Nitrite. (Dog:
Blood-pressure, Respiration, Spleen or Intestinal Loop

Volume, Blood.) 404

CXXIV. Nitrites, Pilocarpine, Adrenaline. (Dog: Bronchial Ac-
tion.) 406

CXXV. Digitoxin. (Frog: General Action.) 407

CXXVI. Digitoxin. (Frog: Heart Tracing.) 408

CXXVII. Digitoxin. (Turtle: Heart Tracing.) 408

CXXVIII. Digitoxin. (Dog or Cat: Blood-pressure and Respiration.) 408
CXXIX. Digitoxin, Strophanthin, Nitroglycerin. (Dog: Pulmonary

Blood-pressure, Carotid Pressure.) 415

CXXX. Digitoxin. (Dog: Heart Tracings, Carotid Pressure.) . . 418
CXXXI. Digitoxin, Strophanthin. (Dog: Diuresis, Spleen Volume,

Leg Volume, Blood-pressure and Respiration.) . . . 420
CXXXIT. Adrenaline, Potassium Chloride, Digitoxin, Strophanthin.
(Cat, Rabbit, Dog: Heart Perfusion Laugendorff

Method.) 424

CXXXIII. Aconitine. (Frog: General Action.) 428

CXXXIV. Aconitine. (Frog: Heart Tracing.) 429

CXXXV. Aconitine. (Turtle: Heart Tracing.) 429

CXXXVI. Aconitine. (Dog: Blood-pressure, Respiration, Tempera-
ture.) 429

CXXXVII. Aconitine. (Dog: Heart Tracings, Blood-pressure.) . . 431

CXXXVIII. Aconitine. (Student: Local Action.) 433

CXXXIX. Veratrine. (Frog: General Action.) 433

CXL. Veratrine. (Frog or Turtle: Heart and Inhibitory Ap-
paratus.) 434

CXLI. Veratrine. (Frog: Skeletal Muscle.) 434

CXLII. Veratrine. (Turtle: Lung Tracing.) 437

CXLIII. Veratrine, Adrenaline. (Dog: Blood-pressure, Respiration,

Intestinal Contraction.) 437

CXLIV. Veratrine. (Dog: Heart Tracings, Blood-pressure.) . . 440

CXLV. Apomorphine. (Dog: Vomiting Center.) 440

CXLA T I. Ipecac. (Dog: Emesis.) 440

CXLVII. Sodium Cyanide, (Hydrocyanic Acid), Sodium Sulphide,
Hydrogen Peroxide. (Dog: Respiration, Blood-pres-
sure, Oxygen Consumption, Blood Glycosuria.) . . . 441

CXL VIII. Quinine. (Frog: General Symptoms.) 447

CXLIX. Quinine. (Frog or Turtle: Heart Tracing.) 447

CL. Quinine. (Frog: Action on White Corpuscles Binz's Ex-
periment.) 447

CONTENTS 11

PAGE

CLI. Antipyrine. (Frog-: General Action.) 449

CLII. Antipyrine, /3-tetrahydronaphthylamine Hydrochlorido. (Dog:

Respiration, Blood-pressure, Leg- Volume.) 449

CLIII. Antipyrine, Peptone. (Two Rabbits: Temperature Regula-
tion.) 451

CLIV. Quinine, Peptone. (Two Rabbits: Temperature Regulation.) 451
CLV. Phenacetiue, Aeetanilide or Aspirin (Acetylsalicylic Acid).

(Fevered Animal: Temperature.) 451

CLVI. Acetylsalicylic Acid (Aspirin). (Student: Headache.) . . 452
CLVII. Phenylsalicylate (Salol). (Student: Excretion, Absorption.) 452
CLVIII. /3-tetrahydronaphthylamine Hydrochloride, Pilocarpine. (Dog:

Oxygen Consumption, Blood-pressure, Respiration.) . . 453
CLIX. Carbolic Acid (Phenol). (Frog: General Action.) ... 454
CLX. Carbolic Acid, Sodium Sulphate. (Dog: Local Action, Res-
piration, Blood-pressure, Spleen Volume, Antidote.) . . 454

CLXI. Phloridzin, Adrenaline. (Rabbit: Glycosuria.) 457

CLXII. Potassium Iodide. (Student: Absorption, Excretion.) . . 457
CLXIII. Alkalies, Acids, Sodium Nitrite, Adrenaline. (Frog: Perfu-

sion of Vessels.) 458

CLXIV. Magnesium, Calcium. (Rabbit: Anesthesia, Antagonism.

Meltzer and Auer's experiment.) 460

CLXV. Arsenic. (Dog or Rabbit: Respiration, Blood-pressure, Peri-
stalsis, Renal Action, Blood.) 460

CLXVI. Antimony (Tartar Emetic). (Dog: Emesis.) 462

CLXVII. Vanadium, Sodium Hydroxide, Ammonia. (Dog: Blood-pres-
sure, Respiration, Spleen Volume, Reflex and Local Ac-
tions, Intestinal or Bladder Contractions.) 462

III. Acid, Alkali Rhubarb, Croton Oil, Magnesium Sulphate.
(Dog: Antagonism of Acids and Alkalies, Absorption
and Excretion of Rhubarb, Local Action of Croton Oil
and Magnesium Sulphate Moreau 's Experiment.) . . 466

PART II.

SHOP WORK.

I. The Shop 470

Equipment 476

List of Equipment 479

Mechanical Procedures 489

Glass Blowing . 49. 1 !

Frog Clips 495

Brass Arterial Cannulas 496

Stands and Castings 496

Lacquering 498

12 CONTENTS

PHOTOGRAPHY.

PAGE

II. Photographic equipment 500

Making negatives 502

Lantern slides 505.

Making prints 508

Blue prints '. 510

LIST OF DEALERS.

List of Dealers in Equipment and Supplies 515

ILLUSTRATIONS.

FIG. PAGE

1. Harvard inductorium 35

2. DuBois-Reymoml induction coil 36

3. Harvard signal magnet 36

4. Signal magnet 36

5. Hale's signal magnet 36

6. Mercury manometer and signal magnet 37

7. Harvard shielded electrodes 38

8. "VYoulff ether bottle with regulating clamp 38

9. Large size tracheal cannula 39

10. Medium size tracheal cannula 39

11. Small size tracheal cannula 39

12. Mohr pinch cocks 40

13. Marey tambour 40

14. Adjustable tambour with three interchangeable bowls 40

15. Stethograph drum 41

16. Kidney oncometer 41

17. Eoy's kidney oncometer 42

is. Arterial cannula 42

19. Beaker 43

20. Dog board and mouth rod 43

21. Animal board and head holder 43

22. Small, white evaporating dish 43

23. Glass bladder cannula 44

24. Graduated cylinder 44

25. Casserole 44

26. Harvard long paper kymograph 45

27. Htirthle long paper kymograph 45

28. Turtle board 46

29. Specimen jar 46

30. Burette and double clamps 46

31. Battery jar 47

32. Small wood tables 47

33. Sri-refine 48

34. Hemostat 48

35. Small sharp-pointed dissecting forceps ... 4s

36. Scalpel 49

37. Small aneurism needle 49

38. Large aneurism needle 49

39. Large blunt-pointed dissecting forceps 49

40. Small blunt-pointed dissecting forceps 49

41. Dissecting scissors 49

42. Dissecting probe (dental) 49

43. Large moderately blunt-pointed dissecting forceps 50

44. Needle holder 50

14 ILLUSTRATIONS

FIG. PAGE

45. Large bottle for holding stock salt solution 52

46. Frog board and clip (Harvard) 54

47. Dissection of a frog showing position of the brain, sciatic nerve and

arteries and muscles of the hind limb (Color plate) .... 54

48. Frog's brain 55

49. Method of pithing a frog 56

50. Harvard moist chamber 57

51. Harvard muscle lever 58

52. Harvard gas chamber 58

53. Ether bottles showing method of administering air and ether . . 59

54. Three forms of containers for ethyl chloride 60

55. Method of smoking drums 61

56. Automatic shellacing pan and drying rack for drum records ... 62

57. Varnishing pan for varnishing records 63

58. Print and tracing trimmer 63

59. Method of arranging the inductorium 64

60. Dissection of a frog to show the position of the heart, vagus nerve

and the muscles of the hind limb (Color plate) '>.">

61. Diagrammatic dissection to show the innervation of the frog's heart 66
(52. Heart lever 66

63. Arrangement of apparatus for recording frog heart tracings ... 67

64. Medicine dropper 68

65. Anatomy of the frog's heart 69

66. Diagrammatic representation of the lymph spaces of the frog . . 70

67. Apparatus for recording turtle heart tracings 72

68. Method of sawing out a square in the plastron of a turtle .... 73

69. Diagrammatic representation of the turtle's heart (Color plate) . 74

70. Schematic representation of the vagus and sympathetic nerves in

a turtle ^5

71. Method of etherizing a dog 77

72. Laboratory table 79 1

73. Metronome for operating the electric time signal SO

74. Lieb-Becker time marker made from an Ingersoll watch ... 80

75. Harvard time clock 81

76. Jaquet chronograph

77. Two forms of time clocks 82

78. Method of fastening the animal's head to the dog board .... 83

79. Heavy string with slip noose ready to put around the fore limb . . 83

80. Method of attaching fore limbs to the dog board 84

81. Method for quickly fastening the string to the board without tyiiiy

any knots S4

82. Method of fastening the hind limbs 85

S3. Method of incising the skin to expose the trachea 86

84. Same as Fig. 83. Separation of borders of sternohyoid muscles . 87

So. Same as Fig. 83. Exposing the trachea 87

86. Same as Fig. 83. Lifting up and passing forceps beneath trachea . 88

87. Same as Fig. 83. Fifth step in the operation 88

ss. Same as Fig. S3. Insertion of the tracheal cannula S9

89. Same as Fig. 83. Lifting up right carotid sheath on an aneurism

needle 89

ILLUSTRATIONS 15

FIG. PAGE

90. Same as Fig. 83. Ligation of the carotid and vago-sympathetic

nerve 90

91. Same as Fig. 83. Opening the carotid artery 90

92. Same as Fig. 83. Insertion of the arterial canmila 91

93. Same as Fig. 83. Final step in operation 91

94. Insertion of femoral injecting cannula 93

95. Dissection to expose the femoral artery and vein and saphenons

nerve 95

96. Same as Fig. 95. Position and relations of the vein, artery and

nerve 95

97. Exposure of the skull for a trephine opening 103

98. Six inch tinner's snips. For cutting thick skin and fascia, etc. . 104

99. Same as Fig. 97. Exposing dura mater 104

100. Trephine 105

101. Upper surface of a dog's brain 106

102. "Straight" glass cannula 107

103. Hand bellows 107

104. Bandage saw 108

105 Method of opening the chest by a median incision 109

106. Method of exposing the left pulmonary artery and vein (Color

plate) 110

107. Applying the cardiometer over the ventricles Ill

108. Cardiometer ' 112

109. Administration of nitrous oxide or oxygen to a frog 114

110. Method for making, purifying and administering nitrous oxide to

a frog 115

111. Yoke for tanks of oxygen, nitrous oxide or carbon dioxide . . . 115

112. A double yoke for holding gas tanks 116

113. Yoke for holding gas tanks 116

114. Guthrie's carbon dioxide generator 117

115. Method for studying the action of nitrous oxide, ethyl chloride,

etc .... 118

116. Apparatus used for closed ether anesthesia 122

117. Table arranged for performing an experiment 123

118. Diagrammatic view of the pan as seen from above 124

119. Tracing obtained by the closed method of anesthesia 125

120. Tracing showing the initial action of nitrous oxide 126

121. Tracing showing the action of nitrous oxide and ethyl chloride . 127

122. Apparatus for intratracheal insufflation 129

123. Apparatus for administering nitrous oxide to an animal .... 130

124. Tracing showing action of carbon dioxide 131

125. Injection of drug solutions into anterior lymph sac of frog . . 134

126. Injection of solutions into anterior lymph sac with a syringe . 134

127. Injecting pipette made of glass 135

128. Arrangement of apparatus for recording esophageal contractions 137

129. Tracing showing four esophageal contractions, blood-pressure and

respiration 138

130. Harvard membrane manometer 139

131. Arrangement of apparatus which may be used as a membrane

manometer 141

16 ILLUSTRATIONS

TIG. PAGE

132. Tracing showing action of alcohol on blood-pressure and respira-

tion 142

133. Dissection showing vessels and nerves in the neck and upper part

of the chest in a dog (Color plate) 142

134. Arrangement of apparatus for recording reaction time for sight . 143

135. Simple key 145

136. Electric tuning fork 145

137. Apparatus for recording reaction time for hearing 146

138. Box for anesthetizing cats 147

139. Bell-jar as used for anesthetizing eats 148

140. Glass or earthen ware jar covered by a glass plate 148

141. Myocardiograph 149

142. Cardiometer arranged for use as a myocardiograph 150

143. Cardiometer made from a large thistle tube 151

144. Arrangement of apparatus for recording heart tracings .... 152

145. Special heart holder 153

146. Heart levers for dogs 154

147. Schematic representation of the innervation of the heart (Color

plate) 154

148. Innervation of heart in the cat 155

149. MyocardiograpMc and blood-pressure tracings from a dog . . . 156

150. Fermentation tube 157

151. Apparatus for recording the pressure of the cerebrospinal fluid . 159

152. Spleen oncometer for dogs 160

153. Spleen oncometer for dogs 161

154. Kidney oncometer 162

155. Rear view of same oncometer shown in Fig. 154 162

156. Kidney oncometer made of a metal pill or ointment box .... 163

157. View showing the oncometer partly open 163

158. Dissection exposing the kidney from a median incision .... 164

159. Arrangement of apparatus for making several records simulta-

neously 165

160. Appearance of the blood-vessels in the ears of a white rabbit

(Color plate) 166

161. Dissection showing position of left pulmonary vessels and sympa-

thetic trunk in chest above diaphragm (Color plate) .... 166

162. Dissection to show the abdominal viscera (dog) 167

163. Electric ophthalmoscope 170

164. Method used for observing the retinal circulation in a frog . . . 171

165. Ventral and dorsal views of a pigeon's brain 173

166. Posterior view of the brain and semicircular canals of a pigeon . 174

167. Lateral view of head of pigeon showing brain, etc 174

168. Base of the brain of a dog 175

169. Upper surface of the skull of a cat 178

170. Mesial section showing the left half of the interior of a cat 's skull 179

171. Dorsal surface of the brain of a cat 180

172. Apparatus for recording and measuring the rate of oxygen con-

sumption 181

173. Inner construction of the pans shown in Fig. 172 182

174. Lateral view of a cross-section of the apparatus shown in Fig. 172 182

ILLUSTRATIONS 1

FIG. PAGE

175. Arrangement for recording oxygen consumption by an animal . 183

176. Apparatus used for making pure oxygen 185

177. Gas reservoir made from a very shallow, wide, round cake pan . 18(5

178. Dreser's apparatus for respiratory measurements 187

179. Technie for inserting a bladder cannula 188

180. Tracing showing action of morphine on oxygen consumption . . 191

181. Kecord showing the action of adrenaline on the rate of oxygen

consumption, uterine contractions, blood-pressure and respira-
tion 192

182. Schematic representation of the course of the right phrenic nerve

in a dog 193

183. Dissection of lower part of neck and upper part of chest on right

side in dog (Color plate) 194

184. Dissection of lower part of neck and upper part of chest and of

axillary region in dog (Color plate) 194

185. Large needles for sewing with heavy twine 195

186. Brass tube with spear point 196

187. Arrangement of animal for recording lung volume changes . . . 196

188. Apparatus for keeping the systematic blood-pressure at a con-

stant level 197

189. Lung volume and blood-pressure record 198

190. Tracings showing the action of morphine 199

191. Tracings showing the action of pantopon 200

192. Tracings showing the action of peronine 201

193. Tracings showing the action of dionine 202

194. Tracings showing the action of narcotine 203

195. Tracings showing the progressive actions of narcophine, narcotine

and morphine 204

196. Method of administering capsules, pills or tablets to dogs . . 205

197. Mercury bulb 206

198. Apparatus for recording bladder contractions 207

199. Same as Fig. 198. Dissection for the femoral vessels .... 208

200. Lung shield made of thin sheet brass 209

201. Method of recording volume changes of the lung by use of the

lung shield 210

202. Tracing showing action of heroine and adrenaline 212

203. Tracing showing the action of codeine and epinine 213

204. Tracing showing the action of muscarine 214

205. Tracing showing the action of codeine on turtle's lungs . . . 215

206. Three kinds of catheters 216

207. Dissection of the pelvis of dog 216

203. Arrangement of apparatus for recording convulsions in a frog . 218

209. Tracing showing the action of strychnine 219

210. Greene's method of irrigating the heart 221

211. Tracing showing the action of strychnine on the turtle's heart . 222

212. Glass oncometer for a small loop of the intestine 223

213. Glass ureteral cannula with rubber tube connection 225

214. Tracing showing the action of morphine 228

215. Tracings showing the action of picrotoxine 232

216. Tracings showing the action of brucine 233

18 ILLUSTRATIONS

FIG. PAGE

217. Method of administering medicine to a dog by means of the stom-

ach tube , . . . 234

218. Mouth gag for dogs, cats or rabbits 235

219. Dissection to expose the sciatic- nerve 237

220. Method of destroying the cerebrum only in a frog 238

221. Tracing showing action of hydrastine 239

222. Innervation of the heart in the frog or turtle 240

223. Tracing showing the action of arecolinc. hydrastinine and ad-

renaline 242

224. Arrangement of a frog and apparatus for recording fatigue trac-

ings 245

225. Showing a method for making cannulas with separable points . . 246

226. Structures in the neck of a rabbit showing the arrangement of the

nerves on the left side (Color plate) 247

227. Glass cannula showing a special washout opening 248

228. Arrangement of two tambours to form a drop recorder .... 250

229. Tracing showing action of sodium sulphate 251

230. Tracing showing the action of curara 256

231. Innervation of the salivary glands in the dog (Color plate) . . 257

232. A turtle prepared for recording lung tracings 261

233. Arrangement of apparatus for recording lung contractions . . . 262

234. Lung tracing from a turtle 263

235. Lung and heart tracings from a turtle 264

236. Diagrammatic representation of innervation of lachrymal glands 265

237. First incision for exposing the chorda tympani nerve, etc. . . . 266

238. Dissection showing positioii and relation of hypoglossal and lin-

gual nerves (Color plate) 266

239. Exposure of the lingual and hypoglossal nerves and salivary ducts

(Color plate) . . . ' . .266

240. Exposure of the chorda tympani nerve (Color plate) .... 266

241. Tracing showing the action of pilocarpine 274

242. General course of the nerves to the salivary glands (Color plate) 274

243. The submaxillary and sublingual glands and their ducts, etc.

(Color plate)' 274

244. A dissection showing position and relations of pancreatic ducts in

dog 276

245. 'Position and relations and method of isolating large duet of

pancreas in dog (Color plate) 278

246. Arrangement of apparatus for recording contractions of intestine. 279

247. Tracing showing the action of barium, adrenaline and atropine . 280

248. Tracing showing action of barium and adrenaline 281

249. Tracing showing the action of arecoline and of atropine . . . 282

250. Innervation of the retractor penis muscle (Color plate) .... 282

251. Tracing showing the action of pilocarpine 283

252. Tracing showing the action of a fatal dose of barium chloride . 284

253. Tracing showing the action of adrenaline and barium chloride . 285

254. Tracing showing the actioii of a fatal dose of barium chloride . 286

255. A form of apparatus used in recording lung tracings 288

256. A form of apparatus used in recording lung tracings .... 289

ILLUSTRATIONS 19

FIG. PAGE

257. Adjustment of the apparatus shown in Fig. 255 in the chest of

a dog 290

2.~>s. Method of making the first incision before trephining the skull . 292

259. The trephine opening 292

260. Method of quickly cutting across the brain stem 293

261. Method of destroying the brain 293

262. Plugging trephine opening with cotton after brain is destroyed . 294
263A. Tracing showing the action of pilocarpine and atropine . . . 295
2(i3B. Tracing showing the action of muscarine and atropine .... 295

2<>4. Tracing showing the action of lodal 296

2(i5. Tracing showing the action of arecoline 298

I'liii. Tracing showing the action of arecoline and atropine .... 299

2<i~. Tracing showing the action of nicotine 301

26s. Tracing showing the action of nicotine 303

L'I'I!!. Method of applying a plethsmograph to the hind leg of a dog . 304

27d. Tracing showing the action of a fatal dose of nicotine .... 305

271. Arrangement of apparatus for recording intraocular pressure . 308

272. Tracing showing the action of nicotine 309

273. Arrangement of apparatus for recording pulmonary blood-pressure 311

274. Dissection showing the method of ligating the left pulmonary

artery 312

275. Second step in preparing to insert a cannula in the pulmonary

artery 312

270. Third step in preparing to insert a cannula in the pulmonary

artery 313

277. Method of inserting the special cannula into the artery .... 313

27s. Special form of separable pointed cannula for pulmonary artery . 315

279. Special (all-glass) form of cannula for the pulmonary artery . . 315

2sn. Tracing showing the action of adrenaline 317

281. Method of dissecting out the orbital fat and fascia to expose the

optic nerve 319

2si_>. Bone cutting forceps 320

L's.'I. Tracing showing the action of lobeline, arecoline and atropine . 323

2s4. Tracing showing the action of lobeline 324

285. Tracing showing the action of lobeline 324

286. Tracing showing the action of pilocarpine 325

28~. Tracing showing the action of lobeline 326

2ss. Tracing showing the action of lobeline 327

289. Tracing showing the action of tetramethylammonium chloride . 329

290. Tracing showing the action of tetramethylammonium chloride . 330
2SU. Tracing showing the action of pilocarpine, and tetramethylam-
monium chloride 331

292. Arrangement of apparatus for recording contractions from a
uterine strip, or from an arterial ring, ureter ring, intestinal

strip, ring of frog's stomach, etc 333

_!.;. Tracing showing the action of muscarine 335

294. Diagrammatic cross-section of the intestine (Color plate) . . . 336

2 ( ..">. Tracing showing the action of nicotine, arecoline and atropine . 336

296. Tracing showing the action of trimethylamine 340

297. Tracing showing the action of pilocarpine and trimethylamine . 341

20 ILLUSTRATIONS

FIG. PAGE

298. Arrangement of apparatus for perfusioii of an excised organ . . 343

299. Tracings showing action of sodium orthovanadate, barium chlo-

ride, and adrenaline 345

300. Tracing showing the action of heroine and adrenaline .... 348

301. Tracing showing effects of cocaine 352

302. Method of exposing the lymphatic ducts and connecting cannulas

to collect the lymph or chyle (Color plate) 356

303. Metallic muzzle for administering an anesthetic to a dog . . . 357

304. View of the reverse side of the metallic muzzle shown in Fig. 303 358

305. Arrangement of apparatus for observing the capillary circulation 362

306. Arrangement of animal and apparatus for recording uterine con-

tractions 364

307. Tracing showing the action of barium chloride 365

308. Tracing showing the action of ergamine Chistamine) and adrena-

line 367

309. Tracing showing the action of ergamine 368

310. Tracing showing the action of tyramine 370

311. Tracing showing the action of adrenaline and ergamine . . . 372

312. Tracing showing the action of ergamine and hordenine .... 376

313. Tracing showing the action in succession of arecoline, lodal, the-

baine, lodal, hordenine and adrenaline 377

. r !14. Tracing showing the consecutive actions of ergotoxine phosphate,

pilocarpine, (ergotoxine) and adrenaline 378

315. Tracing showing the action of arecoline, ergotoxine, (arecoline)

and adrenaline 379

316. Arrangement of apparatus for recording contractions of a uterine

strip, intestinal strip, etc 381

317. Arrangement of apparatus for recording contractions of the uterus

in situ 382

318. Schematic representation of the involuntary nervous system (Color

plate) 384

319. Method of isolating the thoracic duct at the root of the neck

(Color plate) 384

320. Diagrammatic representation of the lymphatic system in a cat . 386

321. Tracing showing the action of pituitrin 3ss

322. Tracing showing the action of pituitrin 389

323. Tracing showing the action of pituitrin 391

324. Schematic representation of the innervation of the eye (Color

plate 394

325. Diagrammatic representation of the structure and innervation of

the eye (Color plate) 394

326. Plethysmograph for recording volume changes in hand and fore-

arm ^ 398

327. Dudgeon 's sphygmograph arranged for recording tracings from

the radial pulse 399

328. Tracing showing action of amylnitrite 400

329. Tracing showing the action of nitroglycerine 405

330. Tracing showing the action of digitoxin 409

331. Tracing showing the action of digitoxin 410

332. Tracing showing the action of digitoxin 411

ILLUSTRATIONS 21

FIG. PAGE

333. Tracing showing the action of digitoxin 412

334. Tracing showing the final result of the action of digitoxin . . 413

335. Illustration showing principles involved in construction of Ed-

munds' liver oncometer 416

33(3. Tracing showing the action of adrenaline 417

.'!.'!7. Spleen oncometer made of crimped sheet brass 421

338. Liver oncometer 42 2

339. Tracing showing the action of tetraniethylanimonium chloride . 423
.">40. Arrangement of apparatus for recording tracings from an excised

heart 425

341. Cat's heart 426

342. Dog's heart 427

343. Tracing showing the final action of aconitinc . 432

344. Tracing showing the action of veratrine 435

345. Arrangement of apparatus for spinning a drum ... ... 436

34(5. Tracing showing the action of veratrine 438

347. Tracing showing the action of sodium cyanide 442

348. Tracing showing the action of potassium cyanide 443

349. Tracing showing the action of sodium cyanide 444

350. Tracings showing the action of dilute sodium cyanide solution . 445

351. Tracing showing the action of pilocarpine and /3-tetrahydronaph-

thylamine hydrochlorkle 450

352. Two tracings showing the action of a drug which markedly lowers

blood-pressure 455

353. Arrangement of apparatus for perfusion of the vessels of a brain-

less frog 459

354. Tracing showing the action of adrenaline sodium orthovanadate,

amylnitrite and adrenaline 463

355. Tracing showing the action of vanadium 464

356. Tracing showing the action of vanadium 465

357. Arrangement of the ligatures for isolating segments of the in-

testine 467

358. A schematic representation of an electric wiring system .... 471

359. Foot bellows 472

360. Diagrammatic representation of an artificial respiration machine 473

361. View of system of pulleys used to operate the interrupting valve 474

362. Lever gate valve 474

363. Diagram showing method of operation of lever gate reversing

valves ' . 475

364. Portable artificial respiration machine 475

365. Special form of interrupting valve 476

366. Special interrupting valve 477

367. A motor driven long paper kymograph 478

368. Detailed view of one plan of construction of the speed regulating

device for the kymograph 479

369. Motor driven long paper kymograph 480

370. Hand drill 481

371. Blast lamp 482

372. Details of the mechanical construction of an adjustable tambour 483

373. A large bowled tambour 484

22 ILLUSTRATIONS

FIG. PAGE

374. Method of tying head of a small screw into rubber membrane . 4X4

375. Some of the more common types of gas pipe fittings 4sii

376. Small electric heater 4*7

377. Method of preparing two pieces of brass tubing for making

a tracheal cannula 4iMi

378. Method of making "straight" glass r-annulas 4 Hi'

379. Same as Fig. 378 ... I '.'I'

380. Same as Fig. 378 4 Hi'

381. Same as Fig. 378 4<)4

382. Same as Fig. 378 4H4

383. Process for making frog clips 4!>5

384. Method for making very small brass cannulas 490

385. Large stand with. L-shaped base . 4!>7

386. Method of arranging the camera and arc light for copying . . 501

387. Method of suspending an adjustable arc light above the operating-

table ">-

388. Measuring glass ">'' | 4

389. Adjustable frame for cutting lantern slide mats 50 7

.390. Frame for making blue prints ->H

INTRODUCTION.

The unit of procedure adopted in this manual is the ex-
periment. Each experiment is, as a rule, complete within
itself, although in many instances an orderly sequence pro-
ceeding from the simple to the more complex, from the
known to the unknown, has been introduced. The writer
has at all times tried to hold in mind the fact that the in-
structor is not only teaching pharmacology but that he is
also teaching medical students. And the mental and tech-
nical abilities and limitations of these students are quite
as significant from the standpoint of the teacher as is the
wide extent, the complexity, and the importance of the sub-
ject which he practically invariably has a too limited time
to cover. It is constantly necessary for the teacher of
pharmacology to bear in mind that the knowledge which
his students possess of the fundamental principles of anat-
omy, neurology, physiological chemistry, pathology, and
especially of physiology, is by no means complete, and much
of the instructor's time must of necessity be consumed in
again bringing to the attention of the students fundamental
and often exceedingly elementary facts involved in the
nature of subjects prerequisite to the course, in pharma-
cology. And it will not infrequently severely tax the in-
genuity of the teacher of pharmacology to determine by
what means he can, within a brief period of time, best
recall to the student's mind some fundamental principles,
e. g., of physiology or neurology, without a knowledge of
which further progress in pharmacology is totally impos-
sible. The author has kept these points carefully in mind
in preparing this manual, and many of the experiments,
illustrations and tracings have been introduced quite as
much with the object of teaching certain fundamental prin-

24 INTRODUCTION

ciples of anatomy, chemistry, physiology, etc., as for their
immediate use in the work on pharmacology.

It has been the author's aim to try to develop experimen-
tally a knowledge of the general principles of pharmacolog-
ical reactions, rather than to lay great emphasis on a vast
array of details regarding the specific action of a long list of
substances. There are more than 100,000 known organic
preparations, with many more theoretically possible. In ad-
dition to this there are some 3,000 or 4,000 inorganic sub-
stances, salts, etc. A very large proportion of these bodies
might be studied separately and individually so far as their
pharmacological properties and reactions are concerned.
And if we attempt to have our students make a fairly in-
tensive study of only the one-thousandth part of all this
vast array of chemical substances, the task is still so great
that perhaps no human mind can grasp and carry within
the memory at any one time the almost limitless extent of
the specific details of the pharmacological reactions of
which even this comparatively small number of drugs may
theoretically be capable. And notwithstanding the more
or less abortive attempts of nearly all recent writers and
examining boards, to limit as far as possible the number of
drugs which the student must study, the task of selection is
still largely one for the individual instructor.

The experiments listed herein are, as a rule, arranged
with reference to individual drugs. The simplest and
easiest experiments on any given substance are usually
placed at the beginning of the section dealing with that
body. Being keenly aware of the difficulty often experi-
enced in obtaining suitable experimental material the
author has included a large number of experiments on frogs
and turtles, the supply of which is less liable to variation
than is that of the vastly more desirable mammalian ma-
terial. Generally a number of experiments are given on
each drug, especially if it be one of importance. It is in-
tended that these experiments be assigned to the students

INTRODUCTION 25

on the day before the experiment is to be performed in order
that each member of the class may familiarize himself with
the work he is expected to do. Many of the experiments
may be done as demonstrations. It is usually advisable for
each group to do a different experiment at any given labora-
tory period. This economizes on the amount of special
apparatus required and also furnishes an opportunity for
each group of students to compare its results with those
obtained by the other groups. This arrangement also gives
an opportunity for the instructor to devote most attention
to those experiments where help is most needed.

The general anesthetics, being of fundamental impor-
tance for the progress of the course, are taken up first.
Following this is a group of drugs chiefly characterized by
their action on the central nervous system. After these
come a series of substances possessing specific actions on
some one or more parts of the involuntary nervous system.
These are followed by drugs which act mainly on the cir-
culatory system, then follow the antipyretics, a few mis-
cellaneous drugs, and finally a few experiments on acids,
alkalies, and some of the heavy metals.

The second part of the book contains two chapters, one
on shop work and one on photography. These are chiefly
of interest to the instructor, and it is advised that these be
read in connection with the general preparation of appa-
ratus, equipment, etc., for the course in pharmacology.

Any general text book on the subject of pharmacology
may be used in connection with this manual, or if the in-
structor prefers to deliver a course of set lectures on the
general field of pharmacology, no didactic text at all may
be required. That is a matter for each teacher to decide
for himself.

Usually drugs are taken up one at a time. It is desir-
able not to confuse the student more than can be helped
by the introduction of too many drugs, especially if the
actions of the drugs involve general pharmacological prin-

26 IXTRODUCTIOX

ciples with which the student is unfamiliar. It often oc-
curs, however, that as the student gains in experience and
in technical ability, drags which have already been studied
may be reintroduced either as a matter of review, or to
demonstrate certain actions of other drugs which are not
evident until brought to light by the changed response of
certain structures to drugs injected secondarily, or to serve
as a check on the action of the apparatus and the general
teclmic employed in the experiment. For this latter pur-
pose great use is made of adrenaline in these experiments.
This often serves the double purpose of reviving an animal
when it is in a very feeble condition, and also gives the
student (aud hixtnictor) an immediate indication of the
accurary of the working of his apparatus and of the condi-
tion of the animal. It should be especially emphasized that
the extensive use made of adrenaline in many of the ex-
periments is solely for the purposes here indicated, and its
frequent injection should not be considered in any sense as
a useless repetition of the same experiment.

It is imperative to use the strictest economy with the ex-
perimental material. For this reason it is desirable for
the students to learn everything possible from each animal
used. Consequently many experiments are listed here in
which a variety of reactions may be recorded at the same
time. The instructor should use his judgment in the case
of each group of students regarding the number of records
which the group will probably be able to successfully se-
cure. And he should not hesitate to eliminate any indicated
part of the experiment in which he believes the group will
fail. The author has, however, often been amazed at the
excellent success which students with some experience may
frequently obtain in carrying out exceedingly difficult and
involved experiments. And the writer recommends that
the instructor should not hesitate to permit a group of
students to attempt to carry out a difficult experiment
whenever he can advisedly do so. For it should be espe-
cially emphasized that a student's own failure may be of

INTRODUCTION 27

vastly more interest and value to him than would be a per-
fect success of that same experiment demonstrated by the
instructor or his assistants.

Many instructors advise that each student in the group
take his turn at doing various portions of the routine work.
In the writer's opinion this will probably not be the most
valuable line of procedure in the long run. For while it
may be very desirable for each student to acquire a certain
amount of skill in performing each part of the experiment
(and students usually want to do this at the start) the fact
remains that the total time devoted to the subject is too
short for any student to become an expert in carrying out
all phases of the work. It will yield a greater percentage
of pharmacological successes for each student to learn a
given portion of the routine work well and to faithfully
carry this out for each experiment. It should be empha-
sized that the chief object of the experimental course is not
to teach surgery, but pharmacology. For while students
may, and in a thoroughly satisfactory course perhaps do,
acquire a very fair amount of the knowledge of surgery
which they will later possess, this should be looked upon
solely as a matter of secondary importance.

Practice dissections on dead animals are frequently de-
scribed at the end of experiments. This is a matter of
great importance and the instructor can often be of much
help to the student by aiding in this work to see that it is
properly done. These dissections usually precede experi-
ments in which the dissected structures will be concerned.

A few words may be said about the matter of dosage.
This is a difficult subject and the writer has been compelled
to depend mainly on his own records and experience in this
line, for most of the published dose tables, etc., are based
on quantities of the drugs to be given by mouth. A further
difficulty arises from the great variation in the size and re-
sistance of different animals, and from the variation in
potency of the different drugs as purchased in the open

28 INTRODUCTION

market. The instructor is advised to make all the observa-
tions he can on this subject for the benefit of his students.

One of the most valuable things which a course in ex-
perimental pharmacology can offer to a student is the very
great opportunity which is presented to develop his power
to think, to observe, and to learn at first hand for himself.
In nearly all of the experiments questions are asked which
are intended to direct his attention to the most vital and
important features of the work, and to encourage him to
test out experimentally the truth or falsity of his own
conclusions.

Every student of modern medicine must have been im-
pressed at some time in his work by the very great aid
which he has derived in his study of anatomy or neurology
or operative surgery from the use of illustrations, dia-
grams, etc, These are frequently of the greatest use for
rapidly reviewing work over which one has long since
passed, or for quickly advancing one's knowledge into fields
with which he may be less familiar. The author has care-
fully considered this phase of the subject in writing the
present manual. And numerous illustrations, tracings, dia-
grams, etc., have been devised and presented with the spe-
cial object of enabling the student, teacher or practitioner
of medicine to quickly and accurately grasp the full mean-
ing and significance of important actions of the drugs con-
sidered. To one who already possesses a moderate famil-
iarity with the subject of modern pharmacology, a brief
glance at the nature of many of the experiments presented,
together with a rapid study of the accompanying tracings,
may reveal the character and results of the effects which
follow the application of drugs to the animal organism with
a vividness which can be exceeded only by the knowledge
acquired by the actual performance of the experiments
themselves.

Finally it may be stated that originality and individu-
ality, not only for the student but for the instructor as well,

INTRODUCTION 29

should be encouraged in every way possible. For experi-
mental pharmacology covers a wide range, and there is at
present perhaps no phase of the whole field of medicine
which promises more for the future alleviation of human
suffering than does this, in a sense one of the oldest, and
yet one of the newest of all the divisions of medical science.

A NOTE TO THE STUDENT.

When pursued under satisfactory conditions experi-
mental pharmacology is one of the most valuable and in-
teresting of all medical subjects. The province of this
work is comparatively new, and unfortunately so far as
the medical student is concerned, is but poorly developed.
The student, as well as his teacher, will feel these limita-
tions mainly in the lack of suitable apparatus and perhaps
in many cases in a lack of sufficient experimental material.
The apparatus as a rule is very expensive and usually is
obtained only with considerable difficulty, while in a large
number of instances equipment suitable for the perform-
ance of many of the most valuable and interesting experi-
ments must be made up according to special directions.
From this it is perfectly obvious that no two schools can
expect to possess exactly the same kind of apparatus for
the performance of any given series of experiments. The
student will often find it necessary to carry out his work
with apparatus entirely different from that described in
the text and often perhaps with an equipment which is
exceedingly unsatisfactory. He should by no means be
discouraged thereby, for much of the most valuable ex-
perimental work of all history has been performed with
crude and unwieldy apparatus, and often under most dis-
couraging circumstances. To accomplish much with little
is a sure sign of ability and the medical student who ap-
proaches the subject of experimental pharmacology at the
present time will find numerous opportunities to demon-
strate his aptitude in this direction. He should seize these
opportunities with keenness and alertness and with a full
appreciation of the advantage which he possesses over
that of the medical student who may have been taught ex-
perimental pharmacology some ten or fifteen years ago.

32 A XOTE TO THE STUDENT

Each experiment in this book was designed primarily to
give the student an opportunity to learn to think, and sec-
ondarily to teach him some valuable point in connection
with the drugs studied. The writer fully appreciates that
there are certain difficulties and limitations beyond which
the average medical student can not go, and for the satis-
factory performance of the following experiments there
has been assumed a certain standard of attainment which
to the author's mind represents approximately that de-
gree of training which the average sophomore student at
the present time should have had when he takes up the
study of experimental pharmacology. The student will feel
constantly the necessity of drawing extensively upon his
knowledge of anatomy, neurology, and physiology, and
to a less extent upon his training in chemistry, physiolog-
ical chemistry, pathology, bacteriology, and physics. And
he must bear constantly in mind the practical clinical ap-
plication and action of the great majority of the drugs
with which he will experiment.

EXPERIMENTAL PHARMACOLOGY

PART I.

PRELIMINARY EXERCISE.

Assignment of Tables and Permanent Apparatus.

At a time previous to the first laboratory meeting if pos-
sible the students will arrange themselves according to
instructions into groups of four or five each. It is gener-
ally desirable (especially if the students are unknown to
the instructor) for the students to arrange these groups
themselves. This should usually be done Avith due con-
sideration of the relative degree of progress and of
ability which each student possesses, students of approxi-
mately equal standing being grouped together.

This is a matter of considerable importance to the
student, for no one cares to drag a poor student through
several weeks of difficult experimentation, while on the
other hand the poorer students should not be cheated out
of their opportunities to learn because other more compe-
tent students do all of the work. The average of the grades
which the students have received in previous courses is
usually a fair basis for forming these groups.

For mammalian experiments students work in the groups
of four or five (rarely three or six under special condi-
tions). Each group of four (or five) is subdivided into
sub-groups of two (or two and three) for work on frogs,
turtles, etc.

Each group of students will be assigned to a table (or
locker) in which the permanent apparatus of the group is
already placed and is in perfect working condition. This

34 EXPERIMENTAL PHARMACOLOGY

apparatus should be checked up quickly, and all omissions
or imperfections sJiould be reported to the technician for
correction. A typewritten list of the apparatus will be given
to each group. Each piece of permanent apparatus be-
longing to a given table is marked plainly with the num-
ber belonging to that table to prevent loss. The perma-
nent list includes :

2 Simple keys (Fig. 135)

2 Heart levers (Fig. 62)

2 Stimulating electrodes (Fig. 1)

2 Sewing needles

2 Signal magnets (Figs. 3, 4, and 5)

2 Induction coils (or 1 induction coil with a double pole, double throw knife,

switch, Fig. 1)

1 Manometer with signal magnet base line marker and tubing (Fig. 6)
1 Ether bottle, tubing and Hoffmann screw clamp or 1 anesthetic device with

oxygen tank, burette, pinch clamps and tubing (Fig. 8)

3 (or 4) Tracheal cannulas (Figs. 9, 10, and 11)
8 Mohr's pinch clamps (Fig. 12)

3 Recording tambours with T -tubes and tubing (Figs. 13 and 14)
1 Stethograph drum (Fig. 15)

1 (or 2) Oncometers, T-tubes and tubing (kidney, spleen, or intestinal loop,

see Figs. 16 and 17)

2 Frog boards (Fig. 46)

2 (to 4) Burettes, tubing and one funnel (small)

1 Large double clamp (to hold frog board, etc.)

4 (or 5) Large stands (Fig. 94)

2 Small stands

1 Pressure bottle, tube, rope and pulley (Fig. 6)

1 Dozen frog clips (Fig. 46)

1 Ball small twine

1 Ball heavy twine

1 Pad of absorbent cotton (a 3-iuch section cut from a I Ib. roll with a

large sharp knife)

2 (or 3) Arterial cannulas (see Fig. IS). More may be needed
2 Beakers, 25 and 50 cubic centimeters (Fig. 19)

2 Small flasks

1 Tube for respiration faucet (for artificial respiration)

1 Dog board with mouth rod (Fig. 20)

1 Thermometer

1 Heart oncometer (cardionieter) (Fig. 108)

1 Small white evaporating dish (Fig. 22)

1 Bladder cannula (Fig. 23)

1 Spool white thread (heavy )

2 Medicine droppers (Fig. 64)

1 Injecting pipette for frogs (Fig. 127)

1 Graduated cylinder, 50 cubic centimeters (Fig. 24)

1 Porcelain dipper (casserole) (Fig. 25)

LIST OF APPARATUS

35

8 Pieces insulated connecting wire (No. 18)

2 Kymographs (Harvard) with 4 fans each (or long paper kymographs, Figs.

26 and 27)

2 Turtle boards (Fig. 28)
1 Specimen jar (Fig. 29)
6 Double clamps (Fig. 30)
4 Burette clamps (Fig. 30)

1 Battery jar, 4-inch (Fig. 31)
6 Test tubes

2 Small tables, 3 inches and 4 inches in height (to support kymographs,

Fig. 32)

1 Test tube brush
1 Pound of ether

Eacli student will sign the following statement at the
bottom of the typewritten list: "We, the undersigned,
have received the above apparatus in good condition, ex-
cept as noted, and for which we each stand responsible to
the department.

Date.

Signed 1 . 4.

3.

5.

6.

Fig. 1. Harvard inductorium with dry cell and simple key in series. In the sec-
ondary circuit is a double pole double throw knife switch to which are connected two
platinum electrodes. By use of this combination two groups of students can use one
inductorium and dry cell without either group disturbing the apparatus of the other
group.

36

EXPERIMENTAL PHARMACOLOGY

Fig. 2. Du Bois Reymond induction coil.

Fig. 3. Harvard signal magnet.

Fig. 4. Signal magnet.

Mm Life record

6econd5

Fig. 5. Hale's signal magnet. When this signal magnet is used with a Harvard

time clock possessing a special adjustment for ten second and minute intervals, three

time records may be recorded simultaneously. (W. Hale: Jour, of Phar. and Exper.
Ther., 1916, viii, p. 445.)

MERCURY MANOMETER

37

Fig. 6. Mercury manometer and signal magnet. The arrangement of the tubing
(M) connecting the pressure bottle (R) and the arterial cannula (and washout, P, U,
V, W) to the manometer is also shown. The pressure bottle should be (adjustably)
suspended about four or live feet above the taole by means of a small rope (T) passing
through a pulley (S) on the ceiling. A. pointer of signal magnet B, which can be
made of a Harvard signal magnet. The rod of the signal magnet has been cut off and
bent to pass down (adjustably) into the hole bored in the upper end of the manometer
board (H) at K. C. writing point of D, the aluminum wire (No. 18) attached to the
manometer plunger E, to the lower end of which the float F, is attached. The inner
diameter of the glass tube TV, should be slightly greater than one-fourth inch and the float
is made (one inch long) from a one-fourth inch polished hard rubber rod. The lower
end of the float is bored out with a 3/16 inch drill to float (full of air) on the surface
of the mercury G. Polished drill rod steel (1/32 inch in diameter) is used for the
plunger which is driven into a small drill hole in the upper part of the float. /, sup-
porting rod of the manometer. /, glass T-tube connected by rubber tubing ( Y) to the
right limb of the U-tube. L, adjustable brass (or iron) wire ( ! s inch) from which a
thread (Z) supports a small weight to hold the writing point on the drum. O, O,
wires running to the signal magnet base line marker (B) from X, X, binding posts
which receive electric impulses from the time clock. It is better but more difficult and
expensive for the U-tube to have a side outlet blown on the right hand limb in place
of the T-tube here shown. The left hand limb of the U-tube should be twelve inches
long. A little oil is placed around the float. The U-tube and T-tube are attached to
th board by copper wires passed through holes and twisted together behind the board.

38

EXPERIMENTAL PHAII M ACOLOGY

Special apparatus for individual experiments Avill be
given out from time to time as needed.

Drum paper will be furnished, 10 sheets at a time, as re-
quired.

Fig. 7. Harvard shielded electrodes.

Ether will be given out in 1 Ib. cans on presentation of a
signed order blank. Ether used beyond the amount esti-
mated to be necessary will be charged for at cost.

Fig. 8. Ether bottle (3-necked Woulff, 500 c.c.) with regulating clamp. The short T-tubes
are made of one-half inch brass tubing (see chapter on shop work).

Drugs and experimental material will be furnished by the
department as needed. The cost of wasted material will
be deducted from the student's breakage deposit.

TRACHEAE CAXXULAS

39

/TT
feb

Fig. 9. Large (one-half inch) size tracheal cannula.

Fig. 10. Medium (three-eighths inch) size tracheal cannula.

Fig. 11. Small (one-fourth inch) size tracheal cannula.

40

EXPERIMENTAL PHARMACOLOGY

Fig. 12. Mohr pinch cocks.

Fig. 13. Marey tambour.

Jma// 5/zea cup

Set screw for

supporting rod

jcmv for
tamoour cup

Tube io
Oncomefer

M&dium sized cup.

' i t ' /"

,,/ Extra \ openings for

\ \supportiny rod

cup

Fig. 14. Adjustable tambour with three interchangeable bowls. All i arts approximately

half natural size.

It is exceedingly important for the student to have some larijc-bwlcd tambours.
None of these are at present on the market and each laboratory must provide for
itself. The ordinary Marey tambour is wholly inadequate for many forms of work
because the bowl is entirely too small. The adjustable form here shown is highly
recommended for all purposes for which tambours can be used. A mechanical drawing
of this tambour is shown in the chapter on shop work where a cheap form of large-
bowled tambour is also described.

STETHOGRAPH DRUM, KIDNEY ONCOMETER

Fig. IS. Stethograph drum, made of 2 </ 2 inch brass tubing. The drum has a length
of 1 54 inches and wire rings are soldered around the edges to act as flanges for holding
on the strings used to tie down the rubber membranes. (For the method of tying on
these membranes and attaching the screws in the center, see Fig. 374 in the chapter on
shop work.) These stethograph drums are not on the market but can easily be made
by any janitor or technician.

Fig. 16. Kidney oncometer, about 2/3 natural size, made of sheet brass. The lid
is placed under the kidney and the box closes over the organ. The latches are turned
inward. The opening out of the oncometer is at the rear as seen in the picture and the
opening passes forward in the square tube into which the round connecting tube is
soldered.

42

EXPERIMENTAL PHARMACOLOGY

tube to recorder

oil enclosed
by membrane

Fig. 17. Roy's kidney oncometer.

Fig. 18. Arterial cannula. used also for injecting into veins. This is liy far the
best cannula for recording blood-pressure or injecting from a burette. Such cannulas
are made to order by glass-blowing firms (see page 515). The opening in the point
should be about 1/32, 3/64 or 1/16 inch in diameter for most purposes. The usual
difficulty is to get the smaller sizes.

LABORATORY APPARATUS

43

Fig. 19. Beaker.

Fig. 20. Dog board and mouth rod. Made of a pine board 1 foot wide and
(or 5) feet long. Not on the market.

Fig. 21. Animal board and head holder (for rabbits or cats).

Fig. 22. Small, white evaporating dish.

44

EXPERIMENTAL PHARMACOLOGY

ssss^SSSSS^^?^^

Fig. 23. Glass bladder cannula, nearly natural size.

Fig. 24. Graduated cylinder.

Fig. 25. Casserole.

LONG PAPER KYMOGRAPHS

45

Fig. 26. Harvard long paper kymograph.

Fig. 27. Htirthle long paper kymograph.

46

EXPERIMENTAL PHARMACOLOGY

Fig. 28. Turtle board, made of cheap, scrap, pine lumber Cold goods boxes). A
hooked wire (sharpened), is attached to the front end. The hook catches in the lower
jaw ("chin") of the turtle. The feet are tied out tightly to the staples.

Fig. 29. Specimen jar.

Fig. 30. Upper picture, burette clamp; lower picture, double clamp (Harvard).

BATTERY JAR, SMALL TABLES

47

Fig. 31. Battery jar (4x5 inches).

Fig. 32. Small wood tables for supporting apparatus, Harvard kymographs, etc.

48

EXPERIMENTAL PHARMACOLOGY

Each student should provide himself with a dissecting
gown, a cheap note book for rough notes, and the follow-
ing dissecting instruments :

1 (or 2) Serrefins (bull-dog artery clamps) (Fig. 33)

1 (or 2) Hemostats (Fig. 34)

1 Pair small sharp-pointed straight forceps (Fig. 35)

Fig. 33. Serrefine.

Fig. 34. Hemostat.

Fig. 35. Small sharp-pointed dissecting forceps.

In addition to this, each yroup of students should further
provide itself with the following instruments for use of the
group as a whole :

2 Good dissecting scalpels. (There is only a very limited use for the knife,
hence not more than two need Vie provided. This may prevent many
poor dissections and bad hemorrhages) (Fig. 36)

2 Aneurism needles (Figs. 37 and 38)

2 Pairs of large blunt-pointed dissecting forceps (Fig. 39)

1 Pair of smaller blunt-pointed dissecting forceps (Fig. 4' 1 )

3 Pairs of dissecting scissors, one large, two small (Fig. 41)

2 Dissecting probes (Fig. 42)

1 Large moderately sharp-pointed dissecting forceps to be used for inserting
cannulas (Fig. 43)

DISSECTING INSTRUMENTS

49

v

Fig. 36. Scalpel.

Fig, 37. Small aneurism needle.

Fig. 38. Large aneurism needle.

Fig. 39. Large blunt-pointed dissecting forceps.

Fig. 40. Small blunt-pointed dissecting forceps.

Fig. 41. Dissecting scissors.

Fig. 42. Dissecting probe (dental).

50

EXPERIMENTAL PHARMACOLOGY

Students are warned not to buy the so-called "sets" of
dissecting instruments. Also do not buy a lot of unneces-
sary instruments. Students who have had human dissec-
tion will usually already possess most of the necessary
(and a good many unnecessary) instruments.

Each student must be provided with a permanent note
book in which is written up a careful description of each
experiment performed. This note book should be well
bound, its dimensions should be about 7 3 /4 inches by 1014
inches, and it should contain about 150 pages. The paper
should be of good quality and all permanent notes must

Fig. 43. Large moderately blunt-pointed dissecting forceps.

Fig. 44. Needle holder.

be written in ink. Avoid typewritten or loose leaf note
books. Either the original or blue print copies of all typ-
ical tracings obtained should be pasted in the permanent
note book and fully explained in the notes. It is urged that
notes be made brief, but strictly to the point. It requires
only a few paragraphs for a student who fully understands
an experiment to tell what ho did, how he did it, and
what his results show. A student should not hesitate to
admit that any given experiment was a failure, or that
part of his results or tracings are wrong. Such errors are
frequent and will lie understood at once by the instructor,
and it is exceedingly valuable to the student to be able to

LABORATORY DIRECTIONS 51

recognize his own failures and if possible to determine the
cause of the failure. And it is of even greater importance
to the student to be able to recognize and to show what re-
sults he should have obtained in an experiment which has
apparently failed. Not only the student, but especially
the instructor, should constantly be on the watch for atyp-
ical or unexpected results. Such chance observations have
often furnished the basis for valuable discoveries.

Blue print copies of the best original tracings (chosen by
the instructor) should be made in the department, usually
by the technician, and should be furnished to the student at
a price which is just sufficient to cover the cost of the blue
print paper. (For directions for making blue prints, see
chapter on photography, page 510.)

It is important that the permanent notes for each ex-
periment be written up as soon as possible after the ex-
periment is performed. The records or tracings should be
labeled in full and great care should be used to make them
as neat and accurate as possible. No more drum space
than is absolutely necessary should be used in making each
tracing. The drum paper should always be smoked good
and black. This is important for blue printing and for
publication if the instructor or anyone else should care to
have any tracing reproduced. It is also necessary for mak-
ing lantern slides. (See chapter on photography, page
500. )

Each group of students will be assigned to a table on
which to work. If a sufficient number of tables and the
floor space are available, it is advisable for each group to
have two tables, one for the experiment and the other to be
used as a side table for arranging apparatus, etc. When
frogs or turtles are used then the two sub-groups (of two
or three) may each have a table. If only one table is avail-
able, then for frog or turtle work the two sub-groups should
work one at each end of the table. It is preferable that the
drawers or lockers for the permanent apparatus be secured

52 EXPERIMENTAL PHARMACOLOGY

by padlocks and that the students themselves furnish their
own locks. This relieves the instructor of much unneces-
sary annoyance.

Special arrangements will be made for individual experi-
ments or for those requiring apparatus which can not be

Fig. 45. Large bottle for holding stock salt solution. Normal tap water saline
(6 or 7 grams of NaCl to the liter) is suitable for most forms of frog or turtle work.

Locke's solution contains: NaCl, 0.92%; KC1, 0.042%; CaCl 2 , 0.024% (crystals);
NaHCO 3 , 0.015%; Dextrose, 0.1%. Ringer's solution contains: NaCl, 0.6%; KC1,
0.0075%; CaClo, 0.01% (dried); NaHCO 3 , 0.1%. Tyrode's solution contains: NaCl,
0.8%; KC1, 0.02%; CaCU. 0.02% (crystals); NaHCO 3 , 0.1%; MgClo, 0.019c; N T a 2 IiPO 4 ,
0.005%; glucose, 0.1%. Dissolve the NaHCO :i before adding the CaClo in each case.

distributed to the class. Much variation will be found in
this respect in various schools. Many pieces of apparatus
must be made up to fit the experiment or the facilities of the
laboratory. (See chapter on shop work, page 470.)

ETHER ANESTHESIA 53

A salt solution (Locke, Ringer, Tyrode, etc.) will be
placed in a large supply bottle in the laboratory. (Fig. 45.)
Sodium citrate solution for blood pressure work will be
supplied by the technician as needed. Unnecessary ivastage
ic III lie charged at cost.

Specific detailed directions are given in the text for the
performance of each experiment, but both students and
instructors should be constantly on the watch for oppor-
tunities to improve the methods and technic given or to
introduce new and better experiments. The writer believes
this to be the best test of the vitality, spirit, and progress
of any course and he never teaches the same set of experi-
ments twice, but, on the contrary, he is constantly trying
to improve or drop the old experiments and to add newer
and better ones. This is even more true for apparatus, and
the writer sincerely hopes that all students and teachers
into whose hands this book may come will gladly contribute
all that they can toward devising better, simpler, and
cheaper apparatus.

More experiments are given in this book than the class
will probably be able to perform. The instructor will se-
lect those best suited for the class and for the facilities of
tlie laboratory. Experiments entirely different from those
in the text may be substituted at any time.

Not more than fifteen minutes should be occupied in
checking apparatus. Immediately thereafter proceed as
follows :

EXPERIMENT I.

Ether, (Action on the Central Nervous System. Cere-
brum.)

1. Under an inverted battery jar (Fig. 31) place a full
grown normal frog. Take a small piece of absorbent cot-
ton and pour a few cubic centimeters of ether on it. Raise
the edge of the battery jar a little and slip the cotton under

54

EXPERIMENTAL PHARMACOLOGY

the jar. The ether vapor will fill the jar and the frog will
presently begin to show symptoms from the action of the
drug. Watch the animal closely. Are there pupillary
changes? Can you distinguish such stages as that of im-
perfect consdmisness, excitement, and anesthesia in the
symptoms exhibited by the frog? Touch the animal from
time to time and when all the reflexes have disappeared,
remove it from the jar and quickly fasten it down to a
frog board (Fig. 46) with clips, in the position shown in
Fig. 47. Do not injure the animal by unnecessary pres-
sure. Place a small piece of cotton over the frog's nose
and mouth and pour a few drops of ether on the cotton.

Fig. 46. Frog board and clip (Harvard). (See chapter on shop work.)

With small scissors quickly make a median longitudinal
incision in the skin above the brain. With the sharp point
of a scalpel, held in the same manner as one holds a pen
in writing, make a series of short shallow cuts in the skull
directly in the median line over the cerebrum (Figs. 47 and
48). When an opening has been made through the skull,
the sharp point of a small pair of scissors may be care-
fully inserted and the opening thus cut larger. Be careful
not to injure the brain. Check hemorrhages with small
plugs of cotton. Expose both lobes of the cerebrum and
then with the point of the scalpel carefully remove from
behind forwards the entire cerebrum. Check hemorrhages
with cotton plugs for a while, but do not compress the optic

1

Cutaneous branch of Femoral art

M. Glutaeus
M. Reef us anterior
M. Vtisfus exfernus
Sciatic artery
M. Triceps fe.moris-~/f ;: .
M. Biceps-
Art Peronea

Art. Suralis

n. Adductor
N. Jibialis
N. Peroneus

fat inf.

M. Peroneus
n. Jib falls anticus

Art mgl/eoldris /gterdlis

Art. malleoldris
Art

N. Cut. cruris lat

* Branch of Ttbial
nerve to Gasfroc-
nemtus muscle

Fig. 47. Dissection of a frog showing position of the brain, sciatic nerve and arteries and muscles

of the hind limb.

ACTIOX OF CHLOROFORM

55

lobes. Remove the cotton plugs and sew the skin together
over the skull with a needle and thread, tie a thread (not
tightly) around the left hind foot and place the animal on
moist cotton in a casserole (Fig. 25) to recover.

The action of ether is largely manifested on the cerebrum,
especially in higher animals. When the animal recovers,

--Olfactory nerve
-Olfactory lobe

- Cerebrum

Pineal body
Jhatamencephahn

- Optic lobe

-Cerebellum
*J---Fourfh ventricle

-Medulla oblongata
Liong. fissure of W vent.

Fig. 48. Frog's brain.

carefully compare its spontaneous and reflex actions with
those of a frog which is just being anesthetized and also
with the condition of the frog after the anesthesia is com-
plete.

Chloroform. (Action on the Central Nervous System.-

Optic Lobes.)

2. In the same manner as in the above experiment, anes-
thetize a frog with a few drops of chloroform. Expose the

56

EXPERIMENTAL PHARMACOLOGY

right optic lobe and remove it. Be careful to avoid injuring
the thalamencephalon or cerebellum. Do not use too much
chloroform. It will produce a profound anesthesia and the
animal may not survive. Tie a thread (not tightly) around
the right fore leg and place the frog on moist cotton in a
covered battery jar to recover. A few hours later (or next

Position of

foramen

mdqnum

AHatpin,or sharp
' Pinted probe

Fig. 49. Method of pithing a frog. A towel is sometimes wrapped around the animal

to facilitate holding it.

day) carefully observe the actions of the animal and com-
pare these with those of the frog with the cerebrum re-
moved. How do these symptoms differ from those exhib-
ited by a frog which is just being anesthetized? Theoret-
ically what symptoms should be shown by a frog which was
injected with a drug that would depress the cerebrum alone :'
Or the optic lobes alone? Place both frogs in the water and
observe their movements. It will be instructive if another
frog can be operated on and the left optic lobe removed.

ETHER, ETHYL CHLORIDE

57

What relation do the optic lobes of the frog bear to the cere-
bellum of mammals?

3. Learn the technic of pithing a frog if you have not al-
ready done so. (See Fig. 49.)

Ether, Ethyl Chloride, Chloroform, Ethyl Bromide.
(Irritability and Conductivity of Nerve.)

4. (a) After pithing place a frog face downward on the
frog board and dissect out the sciatic nerve from its origin

To muscle lever*
To -Secondary coil

Fig. 50. Harvard moist chamber.

at the spinal cord down to the knee. Avoid injuring the
nerve. Tie a thread to the nerve and then dissect the gas-
trocnemius muscle (Figs. 47 and 60) loose from the bones
of the leg. Out the tendo Achillis long and then divide the

58

EXPERIMENTAL PHARMACOLOGY

femur and thigh muscles, but leave the sciatic nerve intact
and attached to the gastrocneinius muscle. Cut the tibia
and fibula just below the knee and free the gastrocnemius
from the remaining tissues of the leg.

Fig. 51. Harvard muscle lever.

The cut end of the femur should now be fastened in the
clamp of a moist chamber (Fig. 50) and a pin hook is passed
through the tendo Achillis as illustrated. The thread

Fig. 52. Harvard gas chamber.

passes down to a muscle lever (Fig. 51) which writes on
a smoked drum. A gas chamber (Fig. 52) held in a burette
clamp (Fig. 30) is placed in position near the muscle (to the

ETHER,, ETHYL CHLORIDE

59

right in the illustration), and by help of the thread the
sciatic nerve is drawn through the holes in the gas chamber
and across the two needle electrodes which are connected to
an induction coil arranged for single shocks. (See Fig. 1.)
By means of a rubber tube, one of the side tubes of an ether
bottle is now connected with one of the tubes leading into
the gas chamber. The boot electrodes (which have been

Hand bellows .

respiration
machine

Fig. 53. Ether bottles showing method of administering air and ether (chloroform)
to an animal with the chest open, or for passing ether (chloroform) vapor through the gas
chamber.

soaked in salt solution and now have been filled with zinc
sulphate solution) may be placed just to the right of the gas
chamber and the end of the sciatic nerve is laid across the
tips of the boots. Keep the nerve and muscle moist with
normal salt solution. The boot electrodes are also arranged
so that single shocks may be sent through them when de-

60

EXPERIMENTAL PHARMACOLOGY

sired. The drum should turn at a moderate speed. Some
ether is now placed in the ether bottle and by means of a
hand bellows a current of air and ether vapor can be passed
through the gas chamber (Figs. 52 and 53). Just before the
other is applied several contractions of the muscle should
be recorded to serve as normal controls. These controls
should be obtained both from the needle and from the boot

GEBAUER5 ETHYL CHLORIO CR

Fig. 54. Three forms of containers for ethyl chloride. The Gebauer container is

preferred.

electrodes. These records should be carefully preserved
and compared with those obtained later. When the normals
have been secured then pass a small amount of ether vapor
through the chamber and then again stimulate the nerve
with the needle electrodes. What action has the ether had
on the irritability of the nerve! Stimulate with the boot
electrodes. Has the conductivity of the nerve been af-
fected? Is this a fair test?

ETHYL CHLORIDE,, CHLOROFORM, ETHYL BROMIDE

61

(b) Blow out the ether vapor with pure air and repeat
the stimulations. Does the nerve return to normal?

(c) With a Gebauer or Kelene tube (Fig. 54) spray a
little ethyl chloride through the gas chamber. Do not
freeze the nerve. Quickly repeat the stimulations and note
the effects on the nerve. What do you observe?

(d) Blow out the ethyl chloride from the gas chamber
and obtain new "normal" contractions of the muscle. If

Fig. 55. Method of smoking drums (in a hood). Benzol is placed in the one pint

milk bottle.

the nerve is dead a new preparation should be made. Place
a few drops of chloroform in the ether bottle and blow the
vapor of this through the gas chamber. Again stimulate
the nerve with the needle and with the boot electrodes.
What do you observe? What can you say as to the relative
action of ether, ethyl chloride, and chloroform on isolated
nerve trunks? Ethyl bromide may also be tried similarly.
Before taking down the apparatus stimulate the muscle
itself directly a few times to determine its condition. This
is easily done if a very fine copper wire instead of a thread

62

EXPERIMENTAL PHARMACOLOGY

Defai/cfffack

Fig. 56. Automatic shellacing pan and drying rack for drum records. \ arnish is
made by dissolving the best granular zclutc shellac in alcohol. A large excess of the
shellac should be present, and solution is allowed to go on for a week or more (shake
up thoroughly several times), at the end of which time the clear supernatant solution
is decanted and placed in a well stoppered bottle to prevent evaporation of the alcohol.
If this occurs small particles of the shellac precipitate out and may spoil the varnished
records by being deposited as white specks all over the black surface of the tracing.
Orange shellac is somewhat more soluble than the white but not so satisfactory because
of the yellowish color it gives to the records. This is very undesirable if any records
are to be blue-printed, photographed or used for publication. Cheap varnishes made
of gasoline and rosin, etc., are sometimes used. A high grade brass lacquer (such as
Kahlbaum's metallfurniss, farblos) may often be much diluted with alcohol and thus
made into an excellent varnish for records.

VARNISHING AND TRIMMING RECORDS

63

Fig. 57. Varnishing pan (12 inches long, 7 inches wide), used for varnishing
records from long paper kymographs. The record is cut apart on the drum, one
person holding each end. The smoked surface is turned upward. One person steps on
a stool (or short stepladder) and lifts one end of the record high in the air. The
assistant dips the other end of the record into the varnish and lifts up his end of the
record as the other end of the tracing is lowered. The tracing is suspended from each
end like a hammock on the rack (shown in Fig. 56) to dry.

Fig. 58. Print and tracing trimmer.

64

EXPERIMENTAL PHARMACOLOGY

is used to connect the pin hook in the tendo Acliillis to the
muscle lever. The secondary terminals can then be at-
tached to the muscle lever and to the muscle clamp.

Ethyl Ohloride. (Local Anesthesia.)

5. Hold a Gebauer or Kelene tube about 10 or 12 inches
from the hand and open the valve a little. A small spray
of the drug will be forced out. Why? Direct this spray

-Time
circuit

Receptacle for lnd c + ori m ^P^ key

electrodes when no+ in use.

The wire of the electrodes should be 6

ft lona ana made of very small sized

/smp-cord

Fig. 59. Convenient method of arranging the inductorium, battery, key and elec-
trodes to avoid tearing down the apparatus at each period. The inductorium is out of
the way and always ready for use.

against the back of the hand. A white frost will soon ap-
pear on the skin and hairs. A few seconds after this frost
begins to form stop the spray and quickly examine the sen-
sibility of the skin in the area affected. To what is this
action due? To what clinical use might this be applied?
Can you think of other substances having a similar ac-
tion? Is this action of ethyl chloride in any way similar
to that of ether, ethyl chloride, or chloroform, on the irrita-
bility or conductivity of nerve trunks? What is the boiling-
point of ethyl chloride ? If a local anesthetic be applied to a
mixed nerve trunk will all the constituent fibers be equally
affected at the same time?

Nfilosso-pharynqeal
Brachial plexus

kX- N -

N.Sup. Larynqeal
N. Vagus''
Lung'

M. Adductor maqnus ^ ^

. Adductor fangus
ft. Sartorius
h. Vdstus internus

M.Adducto?

brevis i

H.Rectus internus minor /
M.Rectus internus major*

M. Gastrocnemius

fl.Tibialis posticus -

M.Eirensor cruris

M. Tibidlis anticus

(Flexor tarsi

Fig. 60. Dissection of a frog to show the position of the heart, vagus nerve and the muscles
of the hind limb. The electrodes are in position for stimulating the vago-sympathetic trunk. It
is often desirable to fasten the electrodes in this position (in a burette clamp) so that the animal
mav not be disturbed when the nerve is stimulated.

ACTION OF ETHER ON THE HEART 65

EXPERIMENT II.

Ether. (Action on the Heart. Dissection for the Vagus

Nerve in the Frog.)

1. Pith a frog and clamp it down to the board with the
central side up, as shown in Fig. 60. With sharp scissors
split the abdominal and thoracic walls in the median line
forward into the skin over the floor of the mouth. If pos-
sible avoid dividing the abdominal vessels. Cut open the
girdle of bones directly over the heart (which should be
carefully avoided) with the scissors. Then pull the tho-
racic cavity widely open by stretching out the fore legs from
side to side. Reset the clamps holding these legs. Refer
to Fig. 60 and identify the glossopharyngeal, hypoglossal,
and brachial nerves. Near the angle of the jaw dissect
down carefully with a probe and fine-pointed forceps until
the laryngeal branch of the vagus and the vago-sympathetic
nerves come into sight. For the method of union between
the sympathetic chain and the main trunk of the vagus
nerve see Fig. 61. The sympathetic fibers pass forward
in the thorax to the base of the skull where they turn back-
wards and unite with the vagus nerve to be distributed
ivith the vagus to the heart, lungs, etc. When, the vago-
sympathetic nerve has been found it should be pulled out-
ward a little and the points of the electrodes slipped be-
neath the nerve. With a tetanizing current of medium
strength stimulate the nerve and see if the heart stops.
This is to identify the nerve. Do not stimulate lite nerve
any longer tlian is absolutely necessary, for the nerve end-
ings are easily fatigued and may not be able to stop the
heart later after your apparatus is all arranged.

The heart is now freed from the pericardium and con-
nected with a heart lever by means of a pin hook and a
thread as shown in Fig. 63. The tip of the ventricle is at-
tached to the pericardium by a small ligament called the

66

EXPERIMENTAL PHARMACOLOGY

frenum. Pick this up with the forceps, sever it, and at the
point where it is attached to the heart stick the pin hook
(which should be small) through the tip oP the ventricle.
Adjust the heart lever to write about one-half inch from
the lower edge of the drum and see to it that the tracing

N.GIosso-

Lei/ator
anquli scapulae

C 'a nation of
Sympathetic/chain

Art- Subdavian

Spinal

nerves

Vertebral
column

Descending
Aorta

(After Oaskell)

Fig. 61. Diagrammatic dissection to show the origin and course of the sympa-
thetic chain and the union of the vagus and the sympathetic fibers for the heart in the
frog (Gaskell).

Fig. 62. Heart lever. The rod is made of 3/16 inch round brass rod into the end
of which a small hole is drilled. A small block of wood fiber or hard rubber is attached
to the rod by a small wire nail which passes (loosely) through the wood fiber block and
is then driven (tightly) into the hole in the end of the rod. The writing lever is a
very thin strip split from a long (10 or 12 inches) section of a bamboo fishing pole.
This lever, which is very light and limber, passes (tightly) through an oblong hole in
the upper part of the wood fiber block. A paper or celluloid (used photographic film)
writing point is attached by mucilage or by a cement made by dissolving a photographic
film in acetone. These levers are entirely satisfactory for the hearts of frogs, turtles,
for uterine strips, etc. They can be made easily and cheaply.

RECORDING HEART TRACINGS

67

starts just to the right of the seam in the drum paper. The
time marker can be arranged and the time recorded as the
record of the heart beat is taken, or the time record may
be put on after the heart tracings are finished if the
speed of the drum is approximately constant. This latter
procedure is advisable for the first few records. It is also
advisable to use a signal magnet in the primary circuit ar-
ranged in such a manner that the exact moment and the

Fig. 63. Arrangement of apparatus for recording frog heart tracings by the sus-
pension method. The wires from the signal magnet are connected with the time clock.

duration of the stimulation may be recorded directly be-
neath the writing point of the heart lever. The heart trac-
ing should have an amplitude of about one-half to one
inch. The drum should have a slow or medium speed. If
the Harvard drums are used it is often advisable to clamp
a folded piece of paper on to the largest fan to thus fur-
ther slow the speed. It may be necessary to put a small
weight on to the long end of the heart lever to secure the
desired amplitude of movement for the tracing.

68 EXPERIMENTAL PHARMACOLOGY

When all adjustments are made start the drum and take
a "normal'' tracing. When about two inches of this has
been recorded then stimulate the vagus nerve and get a
record of the normal inhibition. It is important that the
electrodes do not rest on the neck or thoracic muscles of
the frog, for if such is the case these muscles will contract
when the current is turned on and the frog will move thus
spoiling the appearance of the tracing. Do not stop the
heart longer than is necessary (2 or 3 beats). Then allow
the heart to recover (the drum is kept running) from the
inhibition and record another two inches of "normal'
tracing. Then stimulate the vagus. This gives an oppor-
tunity to secure two sets of records.

Now back the drum aw r ay from the writing lever a little
and turn it back to the starting point. Lower the drum

Fig. 64. Medicine dropper for applying solutions to the heart.

so that the next round of the tracing will be about one-
half inch above the first. Pull the druni forward and
start it again and when about one inch of tracing has been
recorded then drop on to the heart with a medicine dropper
(Fig. 64) five or six drops of a saturated solution of ether in
normal salt solution ( solubility ==1 to 9). When the tracing
again comes directly over the place where the vagus was
stimulated in the lower tracing stimulate the vagus again
and determine whether or not the drug has affected the
reaction of the heart to the inhibition. Now rapidly drop
more ether solution on the heart and repeat the vagus
stimulation directly over the second inhibition record in
the normal tracing. Keep dropping on the drug and note
carefully the effect on the rate and amplitude of the heart.
Observe the appearance of the auricles and ventricles. Can
you determine in your tracing those portions of the rec-
ord made by the sinus, auricular, and ventricular contrac-

RECORDING HEART TRACINGS

69

tions respectively? In which direction does the lever move
in systole?

Take several rows of tracings, lowering the drum suf-
ficiently to leave about three-eighths or one-half inch be-
tween each row of tracings. The record should thus read
from left to right and from bottom to top. As the ether
is dropped on, the action on the systole of the heart will
soon become apparent. This should progress until the
heart almost stops. Then irrigate the heart with normal
salt solution a while and see if you can get it to recover.
Stimulate the vagus from time to time and see if the power

S^T", Ax Carotid Arch

Riaftt

Systemic- *
arch

Pulmo- -
cutaneous arc/)

H/<7/jf Auricle
Truncus arteriosus

Left Ant. Caval

-Left Auricle '
Pulmonary Vein '\ $

-Ventricle

Rn/ht Carotid
/ arc/?

RiqM Systemic

arch

Richt Pulmo -
cutaneous arch

Right Ant
Cava/ Vein

Opening of
Sinus venosus
into the Right
Auricle

-Sinus venosus

Post Cavd vein

Fig. 65. The anatomy of the frog's heart. (Modified from Wiedersheim. )

of inhibition is lost. How has the drug affected the heart?
Is the innervation of the organ involved in the action or
is this mainly a muscular affair? Does this experiment
show any action of the drug on the cardie-inhibitory center
in the medulla? When the heart tracings are finished then
record the time in five second intervals in two or three
rounds on the drum. These time records also serve as
comparison lines to determine whether or not there has
been an increase or a decrease of tone in the heart muscle.
What effect would a decrease in heart muscle tone have
on the position of the record with reference to a horizontal
line drawn around the drum?

70

EXPERIMENTAL PHARMACOLOGY

Chloroform. (Action on the Frog's Heart.)

2. Repeat the above experiment on a fresh frog using a
saturated solution of chloroform in normal salt solution
(solubility ==1 to 200). Does chloroform affect the nervous
inhibiting apparatus of the heart? What differences do you
note between ether and chloroform as regards their cardiac
action I

3. Familiarize yourself with the anatomy of the frog's
heart (Fig. 65). How does the frog's circulatory apparatus
differ from that of a mammal?

Dorsal.

Ventral.

LH posterior lymph u

Fig. 66. Diagrammatic representation of the lymph spaces of the frog.

(Modified from Ecker.j

Chloroform. (Action on Lymph Hearts.)

4. Allow a frog to sit in a good light with the lower end
of the urostyle turned toward a window. On each side of
the lower end of the urostyle (L.H. in Fig. 66) note a series
of feeble pulsations beneath the skin. This is caused by
the beating of the posterior pair of lymph hearts. (The
anterior pair of lymph hearts are located, one heart on
each side, between the transverse processes of the third

ACTION OF ETHER OX THE HEART 71

and fourth vertebrae. Their beats cannot be observed from
the exterior.) Count the rate of lymph heart beats and
also the rate of the blood heart beats. (These can be seen
beneath the skin of the chest.) If the frog breathes also
count the rate of respiration. (How does a frog breathe?)
Now place the frog under a battery jar and deeply anes-
thetize it with chloroform. Remove the animal and again
count the rate of beats of the heart, of the posterior lymph
hearts (do these beat synchronously?), and the rate of
respiration. What conclusions can you draw? Are these
results due to a central or a peripheral action of the chloro-
form? (How is the beating of the lymph-hearts controlled?
How is this mechanism provided for in the mammal?) Al-
low the frog to recover and observe its symptoms. How
long before the frog becomes normal again?

EXPERIMENT III.

Turtle: Vagus Dissection. (Action of Ether on the

Heart.)

1. Pick up a turtle and draw its head forward out of the
shell. This may be done with a wire having a short sharp
hook on one end. The hook is passed between the carapace
and plastron and hooked into the anterior angle of the
lower jaw below. Draw out the head and seize it between
the first and second fingers of the left hand. Clasp the
hand around the turtle's neck and pith it with a sharp
probe or hat pin in the same way that the frog is pithed.
It as advisable to pith the cord also by pushing a soft brass
or iron wire down the spinal canal. The wire is intro-
duced through the same opening by which the animal's
brain was destroyed.

Catch the turtle's lower jaw in the hook of a turtle board
(Fig. 28) in the manner shown in Fig. 67. Pull the hind
legs outward and backward firmly and forcibly and fasten
them to the board. This may be done with strings (heavy)

72

EXPERIMENTAL PHARMACOLOGY

as shown in Fig. 67, but it can be done quicker and per-
haps better by long sharp iron tacks which are driven
through the feet and into the turtle board with a hammer.

Induction.

s Co/7.

Fig. 67. Arrangement of apparatus for recording turtle heart tracings by the sus-
pension method. Note that only a small square opening is made in the plastron over
the heart.

It is very important that the auiiual be fully stretched out
so that it cannot move reflexli/ an<l spoil tJie tracings later.
Next pull out laterally the fore limbs and fasten them down
firmly.

EXPOSING THE TURTLE S HEART (5

Now by means of a hand bandage saw (Fig. 104), or with
a circular saw on a small motor (Fig. 68), cut out a square
opening in the plastron over the heart as shown in Fig.
67. With a scalpel handle pry up the square piece of
plastron and then carefully strip loose the tissues below
the square so as to avoid hemorrhage. There should be
practically no bleeding. With scissors cut away the peri-
cardium and expose the heart. Familiarize yourself with
the anatomy of the turtle's heart (Fig. 69).

In the side of the neck make a longitudinal incision and

Circular
saw

Spindle
extension

Fig. 68. Method of sawing out a square in the plastron of a turtle by means of
a circular saw (3 inches in diameter) attached to a small (1/10 horse power motor).

expose the carotid artery, the vagus nerve, and the sym-
pathetic nerve (Fig. 70). To identify the vagus nerve place
a thread around it loosely, lift up the thread, and with a
moderately strong tetanizing current stimulate the nerve.
Does the heart stop beating? If not, strengthen the cur-
rent. The heart normally should entirely cease to beat
when the vagus nerve is stimulated with a sufficiently strong
current.

Arrange the turtle and apparatus to record a heart trac-
ing as shown in Fig. 67. It may be desirable to use the
signal magnet in the primary current for the induction coil

74 EXPERIMENTAL PHARMACOLOGY'

and thus let the signal magnet record the moment and du-
ration of stimulation rather than the time. After the
heart records have been secured then the time tracing (in
five second, etc., intervals) can be put on the drum. The
electrodes should be adjusted under the vagus nerve in
such a way that the} 7 need not be disturbed or moved in
any way when one desires to stimulate the nerve. Keep
the nerve moist with normal salt solution. The record
should be made in such a manner that it will read from
left to right and from bottom to top. The amplitude of
the beats should be about one inch. The drum should turn
at a moderately slow speed. When all adjustments of the
apparatus are completed record about one or two inches
of the normal tracing and then stimulate the vagus nerve.
The right nerve usually is more effective in stopping the
heart than is the left. Allow the heart to recover (the
drum should be kept going all the time) and when about
one or two inches more of normal record have been ob-
tained, stimulate the vagus (or the opposite vagus) again
and thus get two sets of records. If there are three stu-
dents in "the group it is often advisable to thus make three
sets of records so that each student can have one. The
cardiac inhibitory powers of the vagi in the turtle are not
nearly so easily exhausted by electrical stimulation as are
those of the frog.

When enough normal tracings have been secured lower
the drum so that about one-half inch will be left between
the first round of the record and the second and start over
from the beginning (left hand side) of the record again.
When the second record reaches a point about one inch
to the left of the place where the vagus nerve was stimu-
lated in the first round then rapidly drop ten drops of
a solution of ether in salt solution on the heart as was
done with the frog's heart in Experiment II (1). When
the record comes directly over the place where the vagus
nerve was stimulated in the first round of the tracing stim-

Carotid drt

Subdav.art-
Put mo. art

Cdrotid art

5ubdav/an art
Sup Venae

Pulmonary art

Pulmo.
vein \

Et Auricle

Inf. Vena cai/a

fft. Aortic arc/)

-Left Aortic drch

Coeliac arteries

rDorsal Aorta

Kig. 09. Diagrammatic representation of the turtle's heart. (Modified from Nuhn.)

INNERVATION OF THE TURTLE S HEART

75

Specimen B

Sympathetic ganglia

Sympathetic
nerve

- vagus

nerve

-SympaMef/c
qanqlia

Testudo qraeca Specimen A

Fig. 70. Schematic representation of the vagus and sympathetic nerves in a turtle
(testudo graeca). (Modified from Gaskell.) Variations in the arrangement of the
sympathetic fibers were frequently found by Gaskell. (The writer has seen no instance
in which the arrangement and connections of the sympathetic fibers existed as shown in
this illustration, but the general plan of distribution appears to be approximately the
same in all specimens. )

76 EXPERIMENTAL PHARMACOLOGY

ulate the same nerve again with the same strength of cur-
rent and determine whether or not the nervous inhibitory
mechanism has been affected by the ether. Is the ampli-
tude, the rate, or the tone of the heart affected 1 ? If the
tone of the muscle is lowered how will this affect the trac-
ing? (After the records are all obtained, draw two or
three parallel lines around the drum by rotating it against
the writing point of a stationary signal magnet or tam-
bour. By comparing the general rise or fall of a whole
round of heart beats with this constant line any change in
muscular tone will be observed at once.)

Apply ether solution to the heart rapidly mid at the
proper position stimulate the vagus nerve. Take several
rounds of the tracings (lowering the drum a suitable dis-
tance between each two rounds) and observe the continued
action of the drug on the heart. Does the vagus nerve be-
come more or less effective in stopping the heart? How
do you explain this action? The drum may be stopped for
a while at the end of each round if the changes in the heart
come on very slowly.

When the heart has almost stopped, then proceed to rap-
idly wash off the ether with warm normal salt solution.
See if you can get the heart to recover. How do you ex-
plain any peculiar rises and falls in the general contour
of your tracings? How can you prevent these in later rec-
ords? Were you warned about this before?

Chloroform. (Action on the Turtle's Heart.)

2. Eepeat the above experiment on a fresh turtle using
a saturated solution of chloroform in tap water saline.
Does the chloroform affect the nervous inhibitory apparatus
of the heart? What difference do you note between ether
and chloroform as regards their cardiac action ?

ETHER, CHLOROFORM, ETHYL BROMIDE

77

EXPERIMENT IV.

Ether, Chloroform, Ethyl Bromide. (Dog 1 : Respiration,
Blood-pressure, Cervical Vagi, and Sympathetics.)

1. (a] Read the following directions over very careful ly
at least once before starting the experiment. It is exceed-
ingly important that yon learn the proper technic for the
following procedures correctly at the start. Arrange the
table for the experiment as shown in Fig. 117.

Anesthetization of the Animal. (a) Treat the dog-
gently and kindly and do not irritate or frighten it. Two

Fig. 71. Method of etherizing a dog. The animal should not be frightened or
hurt. (For description see text.)

(or three) students should apply the anesthetic. The ani-
mal is caught by the head and legs and gently placed on
its left side (wliy left?}. If the animal is vicious it should
"be muzzled at the start. The anesthetizer seizes the head
gently but firmly and lays it down on a towel which has
already been placed flat on the floor (Fig. 71). The head
is held by the right hand and the ends of the towel are

78 EXPERIMENTAL PHARMACOLOGY

brought up separately and wrapped about the head. The
right hand then carefully seizes the towel and holds it
tightly around the neck of the dog. The towel thus forms
a kind of sack or tube around the dog's head. The distal
end of this sack is now seized with the anesthetizer's left
hand and twisted around two or three times and then placed
flat on the floor where it is held down firmly with the anes-

/

thetizer's left foot. Both the anesthetizer and the assist-
ant should stand behind the dog. (Why?) The assistant
reaches forward over the animal and holds both fore feet
in the left hand and the hind feet in the right hand. To
prevent the dog from getting up the anesthetizer holds its
head firmly down to the floor with his right hand and the
assistant places one (or both) knees on its body. If the
dog is muzzled, two students can thus control almost any
dog with but little trouble. (In practice one seldom muz-
zles the dog.)

Caution. There should always lie kept in plain view and in easy reach
in the laboratory a bottle of carbolic acid solution and a bottle of alcohol.
These should be kept together and a toothpick with a little cotton wrapped
around one end should be stuck in the cork of the carbolic acid bottle. One
never knows when a student may lie bitten by a dog, and as all dogs or cats
are subject to rabies, airy wound made by the animal 's teeth or claws should
be cauterized with carbolic acid immediately. This is done by wetting the
cotton on the toothpick with the acid and applying it to the wound. In a
few seconds the acid will penetrate the tissues as deeply as the virus has
probably gone and then the acid should be carefully washed off with the alco-
hol. This dissolves out the acid and removes it. The acid may cause the
tissues to take on a whitish, cooked appearance, but the alcohol often removes
this entirely. Do not "kill the animal if the wound appears at all dangerous.
Save it carefully for diagnostic purposes. Consult a first-class bacteriologist
or the city health department.

As shown in Fig. 71 the anesthetizer now drops some
ether on the towel in front of the animal's nose. The dog
will struggle some and should be held firmly. With suf-
ficient ether the animal should be anesthetized in about
two minutes. Be sure the dog gets sufficient air through
the towel. Watcli the respiration closely. The animal will

ANESTHETJZATIOX OF ANIMAL

"9

likely hold its breath at the start. The danger signal af-
ter this preliminary holding of the breath is st<>i>i>(uic or
(jreat shallowness of the respiration. Avoid thi* carffnJJi/.
When the limbs become limp and drop down flaecidly when
lifted and turned loose then touch the cornea gently and
see if the dog winks. If not, hastily place it on a dog board
on the table (Figs. 20 and 72). The animal's head is quickly
drawn forward between the upright posts and the rod is
pushed through between the teeth (just behind the long

HW

Fig. 72. Laboratory table. The top of the table is 5 l / 2 feet long and 33 inches
wide. The height is 35 inches. The small square stand at the head of the table is 13
inches square at the top and has a small (7 inches) round sink in the center. Gas
(G), air (A) (positive or negative pressure, constant or interrupted current), hot (H W)
and cold (C W) water, inductorium or battery current (B). clock current (T), and
drop light circuit (L) are all connected with the (immovable) square stand. The piping
for the water, electricity, etc., runs in the floor. One locker and one large drawer
are available on each side of the table. The dog board is in position on the table.
The sink, etc., should be at the end of the table toward the window.

canines). A heavy twine about sixteen inches long should
have been previously laid across the board just back of
the upright posts. When the rod is pushed in this twine
is then ready to be brought up at once and lied ax tif/litli/
as possible around the dog's mouth just back of the rod.

80

EXPERIMENTAL PHARMACOLOGY

Fig. 73. Metronome for operating the electric time signal.

Fig. 74. Lieb-Becker time marker made from an Ingersoll watch. Time intervals

of 1 second, 5 seconds or 1 minute may be recorded. Obtainable from Mr. J. Becker,

Terrace Avenue, Maywood, N. J. Price $5.50. (See C. C. Lieb: Jour, of Pharm. and
Therapeutics, 1917, 9, 227.)

ANESTHETIZATION OF ANIMAL

81

The operator uses both hands to draw this string tight,
and when the first knot is tied the assistant places his right
thumb over the knot to hold it tightly while the second
knot is tied. Why should this string be tied so tightf/i/

Fig. 75. Harvard time clock.

The average student will probably find out before the first
experiment is finished. The towel is now quickly tucked
down over the dog's, mouth and nose and a little ether is
poured on. The most steady and reliable student in the

82

EXPERIMENTAL PHARMACOLOGY

Fig. 76. Jaquet chronograph (records in intervals of 1/5 second and 1 second).

V

Fig. 77. Two forms of time clocks. (Both made by E. Zimmermann, Leipzig and
Berlin.) The large clock (Bowditch-Baltzar) marks intervals of 1, 2, 3, 4, 5, 10, 15,
JO, 30 and 60 seconds.

ARRANGING FOR OPERATION

83

group now takes charge of the anesthetic and henceforth
directs his attention solely to this ivork. Quickly slip the
cords (each of which lias a slip noose, Fig. 79) over the

Fig. 78. Method of fastening the animal's head to the dog board.

Fig. 79. Heavy string with slip noose ready to put around the fore limb.

fore legs up to the elbows (Fig. 80). Draw these cords
tightly and then wrap the ends around the screw eyes at
the edge of the dog hoard (Fig. 81.) After the third or

84

EXPERIMENTAL PHARMACOLOGY

fourth round draw the end of each cord in between the
screw eye and the edge of the board. This will usually

Fig. 80. Method of attaching fore limbs to the dog board.

Fig. 81. Method for quickly fastening the string to the board without tieing any knots.

hold tightly and saves tying any knots which should be
avoided if possible. Stretch out the hind legs and tie them
down as shown in Fig. 82.

PRELIMINARY OPERATIONS

85

(b) Insertion of Tracheal and Carotid Cannulas; Isola-
tion of Vagi and External Jugular Vein. As soon as the
animal is securely fastened down, a median incision is
made in the skin and fascia over the trachea as shown in
Fig. 83. Observe with great care the teclmic shown in the
illustration and follow it carefullv. Next take two aneurism

Fig. 82. Method of fastening the hind limbs.

needles and separate the mesial borders of the sternohyoid
muscles as shown in Fig. 84. This brings into view the
trachea (Fig. 85) with the carotid sheath containing the
carotid artery and vago-sympathetic nerves on each side
(posteriorly) of the wind-pipe. Next take an aneurism
needle and hook it under the trachea as shoAvn in Fig. 86.
With the largest forceps pick up by one end the heavy
twine to tie in the trachea! cannula. While holding this
in the forceps lift up the trachea with the aneurism needle
and push the forceps (holding the twine) through the

86

EXPERIMENTAL PHARMACOLOGY

fascia back of the trachea. About half the length of the
forceps is pushed through below the trachea and the for-
ceps are thus left in place to hold up the trachea. The end
of the twine is taken out of the forceps and the twine is
drawn through a little over half its length (Fig. 87). The

Left hand of

" Incision -thru skin .
fascia fo Muscle.

Fig. 83. Method of incising the skin over the trachea.

twine is then tied loosely and with scissors the trachea is
cut crosxn-ixi' about three-fourths in tiro (Fig. 87). AVith
large sharp-pointed forceps the operator (right hand) now
holds open the cut portion of the trachea while the assist-
ant (right hand) pushes in the tracheal cannula (Fig. 88).
This is at once tied in and connected with the ether bottle

PRELIMINARY OPERATIONS

87

peedles
how h> tear
Fascist union,
between Sferno-
hyo/c/eus muscles

l~ig. 84. Separation of the borders of the sternohyoid muscles with two aneurism

needles.

.Carotid, sheath.

Conraininq Vaqo-
sy/npafnerfc neri/e
^ Carol-id artery

M. Sterno-hyoideus

Fig. 85. The trachea is exposed and the carotid sheath is seen just to the postero-

lateral border of the windpipe.

88

EXPERIMENTAL PHARMACOLOGY

Operator

Fig. 86. An aneurism needle is used to lift up the trachea while the forceps (holding
the end of a heavy string) are passed beneath the trachea.

Cut Trache?
3/y thru, cross
n wise, between
rinqs.

loosely
tied on

Fig. 87. The string is tied loosely and the forceps are left in position to hold up the
trachea which is cut crosswise about three-fourths in two with the scissors.

PRELIMINARY OPERATIONS

89

Fig. 88. Insertion of the tracheal cannula.

7?t Carotid arkry

Separate
blunt pointed

probe. Do/rr use ftnwe

Fig. 89. lifting up the right carotid sheath on an aneurism needle. A blunt probe is
then used to separate the vago-sympathetic trunk from the artery.

90

EXPERIMENTAL PHARMACOLOGY

Loose liaarure,
P/sCe on with, forceps^
NOT withfin<ie {

Lias fare on
sympathetic nerve

Loose Liy. around arferylj

TJ&C6 077 with forceps, M'/

/YOT wtii finders J|g

Fig. 90. Ligation of the carotid (in two places) and vago-sympathetic nerve.

Fig. 91. Opening the carotid artery. (The incision should be made nearer to the
upper ligature and the scissors should point more toward the heart than the picture
indicates.)

PRELIMINARY OPERATIONS

91

Fig. 92. Insertion of the arterial cannula. The cannnla and tubes contain no solution:
this is run in later after the cannula is firmly tied into the artery.

Posfhon of Exk Juqular V-

Fig. 93. The cannula is tied into the artery. The right external jugular vein is
dissected out by pulling the skin outward while the muscles and fascia are scraped
back inward with the probe. The vein lies in the fascia as indicated.

92 EXPERIMENTAL PHARMACOLOGY

and the screw clamp on the straight end of the cannnla is
adjusted to make the dog breathe just enough ether to keep
the anesthesia constant (Fig. 89). The forceps beneath
the trachea are withdrawn and the aneurism needle is
hooked under the right carotid sheath which is lifted up
out of the wound (Fig. 89). "With a blunt-pointed probe
the sheath is opened and the carotid artery and vago-sym-
pathetic trunk are separated. A ligature is placed under
the nerve and tied loosely. A bull-dog clamp is placed on
the ends of this ligature (Fig. 90) which is now dropped
down beside the neck. Similarly with forceps two more
ligatures are placed on the carotid artery and tied loosely
(Fig. 90). It is extremely important that the student learn
to do these operations with his dissecting instruments
not ivith his fingers except to tie knots, etc. Many stu-
dents bring with them from their anatomy courses an ab-
surd notion that they should do most of their dissections
with their fingers. Learn to use your dissecting instru-
ments. That is the only royal road to first-class operative
success. Place a bull-dog clamp (serrefin) on the carotid
low down in the neck and tie tightly the upper ligature.
The lower ligature lies close to the bull-dog (Fig. 91).
Place the scissors ready to cut the artery about half in
two at a point just below the upper ligature. (Why here?)
The assistant holds a piece of cotton just over the end of
the scissors to catch any blood that may fly out of the seg-
ment of artery as the operator cuts with the scissors (Fig.
91). With the large sharp-pointed forceps the operator
now holds open the artery while the assistant pushes in
the arterial cannula (Fig. 92) which is already connected
with the manometer. The washout tube and clip are also
on the side tube of the cannula. There is no fluid in the
cannula or tube connecting it to lite manometer. This fluid
is run in later when the operation at the neck is complete.
If the tip of the cannula does not enter the artery readily
the cannula should be dipped into a beaker of water and
then inserted into the artery. This is the usual method to

PRELIMINARY OPERATIONS

93

get a cannula into a vessel. The cannula is now tied in
the artery (Fig. 93). (If desired for injections the right
external jugular vein may also be dissected out just be-
neath the skin and fascia of the neck Fig. 93.)

In a similar manner isolate and ligate loosely the left
vagus nerve.

(c) Insertion of Femoral Injecting Cannula; Dissection
of Femoral Artery and Vein and Saphenous Nerve. Ob-

Fig. 94. Burette, tubing, clips and cannula arranged for connecting with a vein for

injection of drugs.

serve with great care the arrangement of the apparatus
shown in Fig. 94. Solutions to be injected into the veins
are placed in the burette. The cannula is tied in the vein,
a bull-dog clamp being ahvays left on the vein just prox-
imal to the cannula. When injections are made the bull-
dog is loosened and the dose is measured by opening cau-
tiously the clip on the tube leading from the burette. As
soon as the drug is injected the spring clip is closed and the
bull-dog is replaced on the vein. This is a double check

94 EXPERIMENTAL PHARMACOLOGY

for safety to prevent the unintentional injection of drugs.
This cannnla is exactly similar to the one in the carotid
artery. Drug solutions in the burette can be changed
quickly by running the solution out at the side (wash-out)
tube. The burette is then rinsed with water and the sec-
ond drug is poured into the burette. To get the air out
of the tubing the two clips are opened a little and some
of the drug solution is washed out at the side tube. The
solution is caught in a beaker and returned to the burette.

When the burette is to be inserted at first some normal
salt solution should be placed in the burette and a little
of it run through the cannula. This wets the inside of the
cannula (and tubes) and prevents air bubbles from stick-
ing inside the cannula later on when the drug is poured in.
Just as the cannula is inserted into the vein some of this
salt solution is run out and the end of the vein next to the
cannula is thus filled with solution and the air is driven
out. If air is left in the tubes, cannula or vein, then the
animal may die of air embolism when the drug is injected.
Always carry out tins technic when putting an injecting
cannula into a vein.

To dissect out the right femoral vein consult Fig. 199.
Place the tip of the finger in the inguinal region just at
the lower outer edge of the abdomen. The pulsations of
the femoral artery will be felt just beneath the skin. With
the large forceps pick up a narrow fold of the skin directly
over the pulsations and cut this fold away ic'rtli the scissors
as shown in the illustration. Do not use a scalpel. When
the skin and fascia are thus cut away an opening resem-
bling that shown in Fig. 95 will be made. With a blunt-
pointed probe dissect away the fascia between the sartorius
and adductor muscles. The vessels will be seen in the
floor of this triangular space as shown in Fig. 96. Use
only the probe or blunt-pointed forceps for the dissection.
When about one-half inch of the vein has been freed from
the fascia slip an aneurism needle under the vessel and lift

PRELIMINARY OPERATIONS

95

it up. Free it from fascia for a distance of three-quarters
or one inch and then with the forceps place two ligatures
loosely under it. Tie these loosely and place a bull-dog
on the vessel close up to the proximal end of the freed
space. The distal ligature is now tied tightly, the vessel is

Cephalad

Fig. 95. A blunt probe is used to dissect the fascia away from the femoral artery and

vein.

lifted on the aneurism needle, and with the scissors a cut
about three-fourths across the vessel is made close to the
distal tied ligature. If the segment of the vessel was full
of blood the assistant should hold a piece of cotton over

Cephaldd rN .S a phenus

n>
</t

5"

Fig. 96. Position and relations of the vein, artery and nerve.

the points of the scissors as the cut is made. The opera-
tor now holds the vessel open (supporting it on the hook
of the aneurism needle) with the large sharp-pointed for-
ceps while the assistant inserts the cannula, running out a

96 EXPERIMENTAL PHARMACOLOGY

little salt solution at the same time. The cannula is now
tied in and the remaining salt solution is run out through
the side tube. The relations of the vein, artery, and nerve
are shown in Fig. 90. You will need to knoir these rela-
tions well for future operations.

Now pour into the empty burette about fifteen cubic cen-
timeters of adrenaline solution 1-10,000 (Parke, Davis and
Co., adrenaline chloride; or synthetic levorotatory adren-
aline, Farbwerke-Hoechst Company, New York. The former
is advisable). Wash out a little of the solution to get all
air out of the tubes. Save the solution washed out and
return it to the burette.

(d) Recording Blood-pressure. Bring the writing point
of the manometer (mercury) to the smoked surface of the
drum. It is exceedingly desirable for the manometer to
carry a signal magnet which marks the base line, or line
of zero pressure, and at the same time marks the time
intervals as recorded from a master clock, Jaquet chrono-
graph, metronome, or other time recording device. The
construction of the manometer is shown in Fig. 6. This
illustration also shows the method of connecting the man-
ometer to the pressure bottle. The best anti-coagulating so-
lution to be placed in the pressure bottle for filling the tubes,
right limb of the manometer and the cannula, is a solution
of sodium citrate (5 to 10 per cent). (Several other salts,
Na 2 S0 4 , NaHCOo, MgS0 4 , etc., in varying strengths, are
sometimes used.) The signal magnet point should mark
about three-fourths of an inch to the left of the manometer
pointer. This avoids breaks in the time record in the
early part of the tracings. Hold a battery jar under the
wash-out tube and open the corresponding clip. Now open
the clip at the top of the manometer. The sodium citrate
solution will quickly run down and fill the tubes, manometer,
and cannula. All air will be washed out. Close the clip
on the side tube while the upper clip remains open. In
this manner run in citrate solution sufficient to raise the

PRELIMINARY OPERATIONS 97

pressure in the manometer until the manometer pointer
writes about one and one-half inches above the base line.
Do not raise this pressure too high. Wliy? See that both
clips are tightly closed and then remove the bull-clog; from
the artery. The pressure in the manometer should rise
sufficiently to lift the writing point about three-fourths or
one inch higher than it was.

The pressure bottle should be suspended from a pulley
at the ceiling and the bottle should be kept about four or
five feet above the table. Some workers put the pressure
bottle on the table and use compressed air to force the
fluid out. The writer advises that this method be avoided
at least in student work, for all the space on the table top
is needed for other apparatus. Furthermore, it sometimes
happens that students do not properly close the clip at the
top of the manometer and then the dog may soon bleed
to death by forcing blood out into the tubes and pressure
bottle, while at the same time citrate solution rather quickly
passes down into the carotid artery. This solution is very
poisonous and soon kills the heart. If the bottle is sus-
pended above the table the instructor can quickly see if any
blood is backing up into the bottle. In addition it is much
easier for the instructor to see at a glance just how much
citrate solution each group of students has ahead for the
experiment.

(e) Recording Respiration. Near the middle of the
thorax pass the long string of the stethograph drum under
the dog (use the hook of an aneurism needle to reach un-
der the animal) and bring it up on the opposite side. Ad-
just the two strings of the stethograph with a moderate
tension and damp them together trith a hemostat or bull-
dog. If too little movement is thus secured for the stetho-
graph membranes place fairly large wads of cotton under
the strings on either side of the chest. Now connect a
rubber tube (which carries near the middle a T-tube with

98 EXPERIMENTAL PHARMACOLOGY

a side tube and clip) to the stethograph drum and attach
the other end of the tube to a tambour which writes on
the drum. The respiratory record should be adjusted to
give an amplitude of about one inch and should be re-
corded below the blood-pressure and about one-half inch
above the base line (recorded by the time signal magnet
on the manometer or by a signal magnet placed separately
on a stand).

(f) Adjustment of Writing Points. On the drum now
adjust the writing point of the manometer in such a posi-
tion that if the blood-pressure falls very low then the writ-
ing point will just barely pass down to the right of the re-
spiratory tambour. This is an important point in te clinic
and must always be foreseen and provided for especially
if three or four tracings are being recorded at the same
time. The anesthetist should have maintained an even
anesthesia throughout these procedures. His guide is the
depth and regularity of the respiration. After the blood-
pressure record is started then it also furnishes valuable
information regarding the depth of the anesthesia. The
respiration, however, is the most important and should be
watched closest. While the anesthetist is personally re-
sponsible for the life of the animal yet it is the duty of
each student in the group to keep as careful and constant
a watch on the animal as possible. Each animal lost care-
lessly should be carefully checked up against the anes-
thetist and his group, and should be duly considered in
making out the respective grades at the end of the course.

There are certain objections to this method of record-
ing the respiration, but it is probably the best one for
student use.

(g) Other Methods of Recording Respiration. Some
workers record respiration by connecting the tambour to
the side tube of the tracheal cannula. If ether is given
through a bottle or if artificial respiration is suddenly

PRELIMINARY OPERATIONS 99

needed this method is of but little use. If the animal be
kept under the influence of a hypnotic such as chloretone,
then it may be of some use. It is best, however, that the
method be avoided, at least ~by students. Cushny has de-
vised a special apparatus for recording respiration where
greater accuracy is required. The apparatus consists of
a long narrow box with one-half or more of the ends (up-
per part) removed. The box can be turned bottom up-
wards over the animal as it lies on the operating table. A
very thin flexible rubber membrane is stretched loosely in-
side the box, being attached (air tight) to the sides and ends.
The bottom of the box (now turned upward) thus forms a
closed cavity over the entire chest and abdomen of the
animal (rabbit). "When the animal inspires the rubber
membrane will be lifted up and the air in the upper
part of the box will be driven out through a tube to the
recording tambour. Another tube in the box carries a
short rubber tube and a screw clamp. This serves as an
adjustable by-pass for the excess air if the tambour is too
small to record all changes (as are all tambours now on
the market). A small spirometer may also be used to re-
cord the respiratory movement by this method. (See also
Cushny and Lieb, Journal of Pharmacology and Experi-
mental Therapeutics, 1915, vi, 451.)

Another method of recording respiration consists in at-
taching a string to the tip of the ensiform (Xiphoid) car-
tilage by means of a pin hook. The string passes over
pulleys to a lever (or to two connected tambours) which
writes on the drum.

(h) Beginning of the Records. Take the bull-dog off
the carotid artery if this has not been done before and ob-
serve the blood-pressure tracing on the drum. Adjust the
pointer and also the respiratory tambour if it is not al-
ready making a satisfactory record. Do not proceed with
the experiment until a perfectly satisfactory record is be-

100 EXPERIMENTAL PHARMACOLOGY

ing obtained. Be sure the drum is wound up and set for
a slow speed.

Start the drum and take two inches of normal record.

2. Stimulate the right vagus nerve (the drum is kept
going) with a moderately strong tetanizing current. What
are the effects on blood-pressure and respiration? How
do you explain this!

3. Open the left eye and while observing the pupil closely
stimulate the left vagus nerve. What do you observe?
How do you explain this? Repeat this on the right side.

4. Crowd on the ether vapor by shutting off the straight
end (for air) of the tracheal cannula and shaking up the
ether in the bottle. The dog thus breathes a very concen-
trated vapor. What effect has this on the respiration and
blood-pressure? Do the heart beats become slower? Can
you determine this with a mercury manometer? Increase
in the amplitude (up and down) of the manometer strokes
indicates a slowing of the heart. Why? What mechanical
factors are involved? Do not mistake the reflected effects
of respiration on the blood-pressure for a change in the
amplitude of each separate heart beat. Allow the animal
to return to normal. Stimulate the vagi nerves. Are they
more or less active in affecting the heart and respiration
than before? What nerves are concerned in these respira-
tory effects and over what paths do the impulses travel?
At what points might an excess of ether affect these?

5. Give the animal a few breaths of chloroform vapor.
This is best done by taking an empty ether bottle (1 pint
milk bottle) and putting about two cubic centimeters of
chloroform into it (Fig. 89). The cork of the ether bot-
tle connected to the dog is now removed and inserted into
the second bottle. The chloroform vapor will be quickly
inhaled by the animal and there will be an immediate change
in the blood-pressure and respiration. Do not allow these
changes to go too far. Remove the chloroform bottle and
allow the dog to recover. Replace the ether. This may be

ASPHYXIA AXD RESUSCITATION 101

repeated two or three times to secure more sets of rec-
ords. Now inject one-fonrth cubic centimeter of adren-
aline. Do you get a normal effect? Ask the instructor
about the appearance of this record. You may need a
larger dose. Compare the effects of ether with those of
chloroform on the blood-pressure and respiration. Which
do you consider safer? Why?

6. Allow the animal to recover. Then place some ethyl
bromide (3 or 4 c.c.) in a second milk bottle and attach it
to the tracheal cannula. Compare the action of this drug
with that of ether and chloroform. Learn the odor of
each of these drugs.

7. If Harvard kymographs are being used one student
should see to it that at least one well smoked extra drum
is always available. Allow the animal to return to a satis-
factory condition and then close off both openings from
the tracheal cannula. The animal will soon become as-
phyxiated. Be sure you secure a good tracing of this.
Observe carefully the changes in blood-pressure and res-
piration. How do you explain these? How do the
respiratory movements affect the blood-pressure? Con-
tinue the asphyxia until either the heart or the respiration
finally stops. What is the immediate cause of death? Now
open the tracheal cannula and at once give the animal
artificial respiration (the ether should be removed) either
with a hand bellows, or better, by means of a special
respiration machine (Fig. 360). Inject one cubic centi-
meter of adrenaline solution. The lungs should be inflated
about twenty or twenty-five times per minute. Does this
affect the heart or respiratory center? Continue it for
ten minutes if the animal does not recover sooner. Stop
when you detect sufficient signs of recovery and allow the
animal to return to normal. Now give the animal suffi-
cient chloroform to stop both heart and respiration. Im-
mediately apply artificial respiration and try to revive the
dog as you did before. Compress the chest over the heart

102 EXPERIMENTAL, PHARMACOLOGY

intermittently with both hands. Watch the movements of
the manometer as you compress the heart. Does this af-
fect the blood-pressure? Quickly inject from the burette
two cubic centimeters of adrenaline solution and continue
the artificial respiration and heart massage for ten min-
utes if the animal does not recover sooner. What treat-
ment would you advise for threatened death under an
anesthetic? How would you apply this treatment in a mod-
ern hospital? If the animal revives (it of course never
comes out from under the influence of the anesthetic) then
again clamp off the wind pipe and allow it to die of as-
phyxia.

8. If time permits make the following dissections: Open
the chest by a median incision over the sternum. To do
this incise the skin and fascia down to the sternum, and
saw (Fig. 104) this through exactly in the median line.
(See Fig. 105.) Pull open the chest from side to side and
expose the lungs and heart (inside the pericardium). In-
flate the lungs. Open the pericardium and expose the
heart. Observe all the important structures in the chest.
Cut the phrenic nerves where they lie on the pericardium.
Could you make this dissection in a living animal?

9. Carefully clean up the table, manometer tubing, can-
nulas, etc., and put away all your apparatus. It is im-
perative for each group to clean up its own apparatus after
each experiment. The animal must be put in a garbage
can or box with the others and should be burned in the
furnace at the power or heating plant.

The records obtained during the experiment should be
labeled at once. The appearance of the record can often be
greatly improved by drawing a few straight lines horizon-
tally through the tracings by rotating the drum against a
stationary tambour pointer before the paper is removed
from the drum. (See Fig. 190.) Rough notes should be
made during the experiment. The record is varnished and
dried, and the permanent notes should be written up as soon
as possible.

ETHER, CHLOROFORM, ETHYL BROMIDE

103

EXPERIMENT V.

Ether, Chloroform, Ethyl Bromide. (Dog: Motor Areas,
Blood-Pressure, Blood, Heart.)

1. Arrange a dog as in Experiment IV, for recording
blood-pressure. Put adrenaline solution in the injecting
burette (in the femoral vein). Be sure the anesthesia is
regular and sufficiently deep.

2. Loosen the dog's mouth and the right fore leg. Turn
the head and part of the chest over toward the left so as
to leave the top of the head turned well over to the right.
If the instructor advises it turn the dog's head entirely

Fig. 97. Removal of a triangular area of skin and fascia over the skull for a trephine

opening.

over so that the top of the skull is directed upward. In
this case watch that the respiration is not hampered or
that the carotid or tracheal cannulas do not become dis-
turbed by compression of the carotid artery or trachea.
Observe Fig. 97 carefully. Make a median longitudinal
incision in the skin and fascia down to the skull as shown
in the illustration. With large scissors (Fig. 98) cut out
a triangular piece of skin and fascia. At the place marked

104

EXPERIMENTAL PHARMACOLOGY

"C in Fig. 99 a curved line will mark the point of at-
tachment of the temporal muscle (T). AVith a scalpel cut
the edge of the muscle loose from the bone exactly in this
line. Now dissect the muscle loose from the skull bv cut-

Fig. 98. Six inch tinner's snips used for cutting thick skin and fascia, etc.

ting the periosteum from the bone and reflecting the muscle
outward from the median line. Be sure to keep the dis-
section and cutting close down to the bone to avoid the

Fig. 99. A trephine opening (O) has been made in the skull (5) and the dura
mater (B) beneath is exposed. The electrodes can be applied to the dura mater over
the various centers in the motor area. C, line of attachment of the reflected temporal
muscle (T). .!/, median line beneath which is the great longitudinal sinus.

muscular blood vessels. Pull the reflected edge of the
muscle upward with a hemostat as shown in Fig. 99. Now
take a trephine instrument (Pig. 100) and at a point about

EXPOSURE OF MOTOR AREAS

105

one-half or three-fourths inch from the median line make
an opening through the skull. (It may be necessary later
to enlarge this opening.) Be sure to keep far enough out
from the median line to avoid the great longitudinal sinus
inside the skull (8). (If this is opened accidentally quickly

Fig. 100. Trephine.

remove the trephine instrument and tightly plug the open-
ing with cotton to stop the hemorrhage. Then turn the
animal over and perform the operation on the left side.)
Remove the button of bone and the dura mater over the

106

EXPERIMENTAL PHARMACOLOGY

brain should be seen as shown in Fig. 99. Now allow the
anesthesia to become as light as possible without letting
the animal come out from under the influence of the ether
too much. With the platinum electrodes (medium tetaniz-
ing current) begin to stimulate the exposed dura mater at
various points. Try to pick out some centers for various
muscular movements. Observe Fig. 101. Make careful

- Longitudinal sukus

Crucial sukus (Fissure of Rolando)

I _,

.Center for the neck muscles.

center for the extensors &-
adductors of the f or el i mo.

.center for the flexors &-
rotation of the fore/imb.

-center for the hind limb.

center for the muscles
innervated by the facial.

Fig. 101. Upper surface of a dog's brain. (Modified from Sisson.)

note of the position of the electrodes for each of these
centers and observe closely the extent and strength of the
movements produced. Be sure you understand the an-
atomy of the nervous paths l>y which these movements are
originated and controlled. Now deepen the anesthesia and
again stimulate. Is there any change in the response of

ETHER, CHLOROFORM,, ETHYL BROMIDE

107

the muscles'? Again lighten the anesthesia and secure
more "normal' 1 movements. Now give the animal a lit-
the (not too much) chloroform and again stimulate. Are
the movements affected in any way? How does this com-
pare with ether? If the instructor advises it the action of
ethyl bromide on the motor areas may be tried also. Re-
place the animal in the usual position and re-adjust your
apparatus.

Fig. 102. "Straight" glass cannula. Several different sizes of these are often needed.

3. Dissect out one femoral artery (Fig. 96) and place
in it (pointing toward the heart) a small straight cannula
(Fig. 102). Leave a bull-dog clamp on the artery proxi-
mal to the cannula. Into a test tube draw off about three
or four cubic centimeters of blood from the artery, and
at once pour an equal quantity of ether into the blood.
Shake the two together for a few seconds and set the tube

Fig. 103. Hand bellows.

aside for two or three minutes. Then observe the appear-
ance of the blood. Can you detect any changes? How do
you explain this?

4. Kepeat this with chloroform. Do these tubes of blood
clot?

5. Repeat with ethyl bromide.

6. Cardiometer. Arrange for artificial respiration. If

103

EXPERIMENTAL PHARMACOLOGY

possible this should be done with a thoroughly reliable res-
piration machine (Fig. 360). If this is not available then
use a hand bellows (Fig. 103). Prepare a needle and thread
and four strong twine (heavy) strings about eighteen
inches long.

With the scalpel make a median longitudinal incision in
the skin and fascia over the sternum. The incision extends
from the root of the neck to the end of the xiphoid cartilage.
When the fascia and muscular layers come into sight a
number of blood vessels will be seen passing mesially in
pairs to the midline of the sternum where they pass into
the chest. Do not cut these vessels if it can be avoided

Fig. 104. Bancage taw.

(which is sometimes impossible). In the center line it is
usually possible to cut between the ends of each pair of
vessels and thus avoid much hemorrhage.

If a vessel is cut clamp it with a hemostat. The bleed-
ing should soon cease. Have plenty of absorbent cotton
(in small wads) at hand to sponge off the operative field.
When the center line of the sternum is reached then take,
a saw (Fig. 104) and saw open the chest as shown in Fig.
105. Start tie artificial respiration as soon as any open-
ing is made into the chest. It is exceedingly Important to
keep the incision in the center line. If this is done prac-

OPENING THE CHEST

109

tically all important blood vessels will be avoided. Just
inside the chest the mammary vessels will be found on
each side of the midline. These vessels should be sepa-
rated, each pair remaining attached to the under surface
of its corresponding side of the sternum. If one of these
vessels is cut it must be quickly caught with a hemostat
and then a string is pushed (with the large sharp-pointed
forceps) through the chest wall close to the lateral sternal

Fig. 105. Method of opening the chest by a median incision.

border and the end brought around inside the chest. This
string is now tied firmly and should shut off the vessel on
one side of the cut place. But a second string is generally
needed on the opposite side of the opening in the vessel
to prevent hemorrhage from the other end of the vessel.
All hemorrhage should be checked before one proceeds
with the experiment. When all bleeding has stopped then
(with the forceps) pass the four large twine strings through

110 EXPERIMENTAL PHARMACOLOGY

the margins of the chest avails as shown in Fig. 106. Tie
these ends, draw the chest wall open, and fasten the strings
to the operating board as shown in Fig. 107.

This fully exposes the lungs and the heart which is cov-
ered by the pericardial sac. Did you see the anterior
mediastinum? What became of it? With scissors open
the pericardium in the midline. Then bring the cut edges
of the pericardium out laterally and sew them (with two
or three stitches on each side) to the chest wall. This
forms a kind of hammock in which the heart lies. The
animal must be given sufficient ether to keep it quiet all
the time. Observe carefully the beating of the heart and
the movements of the lungs. Did the blood-pressure fall
much when you opened the chest? It should not. Does
the heart rise and fall as the lungs are inflated and de-
flated? If so, try to reduce the extent of inflation a little
and see if the animal does Avell (blood-pressure remains
normal and convulsive movements do not appear). This
rise and fall of the heart is the most troublesome thing
concerned in the taking of heart tracings. Now take the
cardiometer (Fig. 108) and stretch the rubber membrane
outward from the opening, rolling part of the edge of the
membrane back over the metal rim. Now place the cardi-
ometer down over the heart (ventricles only, see Fig. 107)
and bring the membrane down to the auriculo-ventricular
groove. Roll the edge of the membrane off the metal part
and allow the opening in the membrane to close around the
auriculo-ventricular groove. Does the blood-pressure re-
main normal? If not, wait a little and if necessary re-
adjust the cardiometer. Connect the cardiometer tube with
a recording tambour which may write either above or be-
low the blood-pressure, depending on whether the pressure
is low or high respectively. Adjust all writing points and
take two or three inches of "normal" tracing. The cardi-
ometer record should be one or two inches in amplitude.

Tig. 106. Method of exposing the left pulmonary artery and vein. /-. lung. P, phrenic nerve
lying on the pericardium (//) over the heart. D, the diaphragm.

CARDIOMETER TRACINGS

111

Stimulate one vagus nerve and see how this affects the
tracings. Allow the heart to recover and take two inches
more of "normal" tracing. Now crowd on the ether and
note the effect on the pressure and cardiometer tracings.
What does the cardiometer tracing show with respect to
the heart? Be sure you describe this fully and correctly
in your notes.

Faucet from
artificial
resp/'rafro/) Ha^d
machine

Fig. 107. Method of applying the cardiometer over the ventricles. Artificial respi-
ration is carried on either with a hand bellows or by an artificial respiration machine.
The ether bottle has a by-pass so the amount of anesthetic can be regulated. The excess
air escapes through the tube in the straight end of the tracheal cannula which is regu-
lated by the screw clamp to give the desired amount of expansion and exhaustion of the
lungs.

Allow the animal to recover and then give it some chloro-
form. How does this compare with ether? Now inject
one-half cubic centimeter of adrenaline. Plow does this
affect the heart? Is the drum going fast enough to show
the individual heart heats?

Allow the animal to return to normal and then give it

EXPERIMENTAL PHARMACOLOGY

some ethyl bromide. How does this affect the heart! In-
ject a little adrenaline and let the animal recover.

(It will be interesting to try ethyl chloride also. It can
be sprayed into one of the rubber tubes going to the tracheal
cannula. To do this an extra T-tube may be placed in the
circuit. )

Fig. 108. Cardiometer. (See also Fig. 143.)

7. Dissection of Pulmonary Artery and Vein. Remove
the cardiometer and cut the stitches that hold the peri-
cardium to the chest wall. Pull the pericardium and heart
all over toward the right side of the animal. Observe the
left pulmonary veins at the root of the lung. Observe Fig.
106 closely. At the base of the heart observe the aorta
passing back posteriorly and then turning caudalward. In
the hollow of the arch of the aorta between it and the
heart a curved eminence covered with white fascia will be
seen coming from the base of the heart and passing down-
wards, outwards and backwards into the lung beneath the
most prominent pulmonary vein. With a blunt probe care-
fully dissect away some of the fascia over the curved emi-

NITROUS OXIDE,, CARBON DIOXIDE, OXYGEN 113

nence, and the left pulmonary artery can be seen passing
out into the base of the lung. Place an aneurism needle
beneath the artery, raise it up and clear a section of the
artery about three-fourths of an inch long with the probe.
Could you put a cannula into this artery and record the
pulmonary blood-pressure! The heart will probably have
ceased beating by this time. If it has not, stop the respira-
tion and let the animal die. // time permits it will be very
instructive to try to revive the heart by massage and by
injecting adrenaline. Keep up the artificial respiration
during these efforts.

EXPERIMENT VI.

Nitrous Oxide, Carbon Dioxide, Oxygen. (Frog: Central

Nervous System.)

1 . Place a frog in a one pint milk bottle as shown in Fig.
109. Arrange a nitrous oxide tank (and an oxygen tank
also if the laboratory can afford one if not omit the oxy-
gen) as shown in the illustration. The apparatus shown
in Fig. 110 may also be used if a nitrous oxide tank is not
available. Observe (and count) the rate of the frog's res-
piration, lymph heart beats and heart beats. Note the
size of the pupils, position which the frog assumes, etc.
Now open the N 2 tank a little and run into the bottle a
very small amount of the gas. Make a note of the time
of day. The outlet must be opened as the gas is run in,
for these taiiks may have 1000 pounds or more pressure
to the square inch and would quickly burst the bottle or
blow out the cork. AVatch the frog carefully as it begins
to breathe the gas. Does it show any signs of suffocation?
There was already sufficient oxygen in the bottle to run
the frog some time. Gradually run in more N 2 and watch
carefully for the first symptoms shown by the frog. As
the atmosphere in the bottle becomes more and more filled

m

EXPERIMENTAL PHARMACOLOGY

with the gas the frog will manifest distinct symptoms.
How long does it take to completely anesthetize the ani-
mal? When this stage is reached count the respirations,
lymph heart beats and heart beats. Inject a little oxygen
from time to lime and see if the animal comes out from

Wheel wrench

Fig. 109. Administration of nitrous oxide or oxygen to a frog.

under the anesthetic. As the oxygen increases in the
bottle the frog will recover. How long does this take and
how long a time is required to anesthetize the frog in the
first place? How does this anesthetic compare with ether
or chloroform or ethyl bromide?

2. Place another frog in the bottle. Note the time of

NITROUS OXIDE ANESTHESIA

115

day. Turn on the N 2 and fill the bottle at once with this
gas (washing most of the air out of the bottle with the
N 2 0). How long does it take to anesthetize the frog? When

Fig. 110. Method for making, purifying and administering nitrous oxide to a frog.
Strong solutions of ferrous sulphate, sodium hydrate and concentrated sulphuric acid
are placed in the wash bottles.

Fig. 111. Yoke for tanks of oxygen, nitrous oxide or carbon dioxide. These yokes
are attached to the tanks and a rubber tube is slipped over the nozzle of the yoke.
When the valve of the tank is opened a little the oxygen passes out through the tube.
The yokes can be obtained of dealers in surgical supplies or from the Lennox Chemical
Company, Cleveland, Ohio (Price $ .75).

the animal is deeply anesthetized remove it quickly from
the bottle and see how long it takes for complete recovery.

116

EXPERIMENTAL PHARMACOLOGY

Keep a record of these periods of time. Does the frog
again become completely normal?

3. Place another frog in the milk bottle. Xow inject C0 2

Oxygen

-Leather washer-

Nitrous

oxid

^

Fig. 112. A double yoke for holding gas tanks. Made by bolting together two bars

of iron.

Fig. 113. Yoke for holding gas tanks. Made of gas piping and fittings (see chapter

on shop work).

into the bottle. This may be done from a tank or from a
Guthrie generator (Fig. 11-1). Observe the effect on the

NITROUS OXIDE, ETHYL CHLORIDE, CARBON DIOXIDE 117

animal. How is the respiration affected? How does this
compare with the action of N 2 ? If you have oxygen, run
some of this into the bottle and see if this counteracts the
C0 2 .

Fig. 114. Guthrie's carbon dioxide generator. Two quart milk bottles are used to hold
blocks of marble 'and dilute acid (A) and the wash water (bottle B).

EXPERIMENT VII.

Nitrous Oxide, Ethyl Chloride, Carbon Dioxide, Increased
Atmospheric Pressure, (Decreased Atmospheric Pres-
sure). (Frog, Guinea Pig, Rat, Kitten, or Pup.)

1. Place a frog and a guinea pig (or other small mam-
mal see that the frog is protected) in a large bottle ar-
ranged as illustrated in Fig. 115. Open the outlet and run

118

EXPERIMENTAL PHARMACOLOGY

some oxygen into the bottle. What effect does this have on
the animals? It is to be noted that this experiment permits
comparison of the relative effects of the substances ad-
ministered on warm-blooded and cold-blooded animals. The

Outlet
Gebauer's eihyl chlorid

Fig. 115. Method for studying the action of nitrous oxide, ethyl chloride, carbon
dioxide, oxygen, increased (or decreased) atmospheric pressure on warm and cold-blooded
animals.

skin absorption or excretion of the frog should be held in
mind. Increase the amount of oxygen in the bottle. Then
with the greatest caution raise the oxygen pressure in the
bottle by closing the outlet and opening the clip on the tube

ATMOSPHERIC PRESSURE CHANGES 119

going to the manometer while more oxygen is run in. Do
not Now out the mercury by turning on the oxygen sud-
denly. What effect has this increased pressure on the ani-
mals f

2. If a suction pump (or negative air pressure) is avail-
able this may now be used. Open the outlet and connect
this to the suction pump or negative pressure faucet. Open
the clip to the manometer and exhaust the air in the bottle
as many centimeters of mercury as the oxygen pressure has
been raised. What effect has this on the animals?

3. Wait a few minutes to note how the animals act and
then again open the outlet and equalize the pressure inside
and outside of the bottle. Koll up four or five sticks of
sodium or potassium hydrate in wire gauze and put them
in the bottle in such a position that the animals cannot
touch the alkali. What is the purpose of this? Be sure
the alkali does not rest directly on the bottom of the bot-
tle. Why? Allow the animals to become quiet again and
then begin to gradually run N 2 into the bottle, leaving the
outlet open as gas is injected. Bring on the anesthesia by
very gradual degrees and do not excite the animal if pos-
sible. Do you notice any symptoms of somnolence in either
animal! Or do you note symptoms of excitement and con-
vulsive jumping-like movements? After the animals be-
come completely anesthetized begin to admit oxygen. How
long does it take to produce complete anesthesia? Be care-
ful that the oxygen does not become too low. If th ; s occurs
one animal may die. Which one? Is it possible f o you to
estimate how much oxygen (i. e., what per cent) you admit
by closing the outlet and raising the atmospheric pressure
in the bottle a given number of millimeters of mercury?
Try to so balance the proportions of N 2 and oxygen in the
bottle that you can maintain a regular anesthesia in the
animals for ten or fifteen minutes.

4. Now gradually admit more and more oxygen and note

120 EXPERIMENTAL PHARMACOLOGY

carefully the recovery symptoms. What principles are in-
volved in nitrous oxide analgesia or anesthesia ? How long-
does it take the animals to become normal? How does this
compare with ether?

5. Eemove the alkali and allow the animals to become
normal, or much better, get two fresh animals (a small tur-
tle may also be included if the bottle is large enough) and
then with the animals in the bottle run in a little C0 2 . Note
the changes in rate and depth of respiration if any occur.
Add more C0 2 . Can you produce an anesthesia with CO. :'
Read this up in your text. Compare the symptoms in the
two (or three) animals. Allow the animals to recover.

6. Paul Bert's Experiment. Replace the alkali in the
bottle and again run X 2 into the bottle but leave the outlet
open. In this way wash out the air and obtain almost a
pure atmosphere of N 2 0. Do not iraste any more gas than is
necessary. (As soon as marked symptoms of asphyxia ap-
pear add a little oxygen.) When nearly all of the air (nitro-
gen) has been run out of the bottle then close the outlet and
wait a little if the animals are not unconscious and do not
show too marked symptoms of asphyxia. Then slowly raise
the pressure in the bottle by admitting oxygen. Paul Bert
found that in an atmosphere consisting of eighty per cent
X 2 and twenty per cent oxygen, hut with the pressure
raised one-fourth above the normal atmospheric pressure, a
complete nonasphyxial anesthesia could be produced and
maintained indefinitely. Can you repeat his experiment?
What gas does an animal give off in its expired air? What
is the fate and mode of excretion of absorbed nitrous oxide?
In what form is it carried in the blood! How does this
compare with ether and chloroform or ethyl chloride or
ethyl bromide! What is the purpose of the alkali in these
experiments !

7. Allow the animals to recover (or obtain fresh ones).
Place them in the bottle (the alkali should also be in) and

CLOSED METHOD OF ANESTHESIA

then inject a small amount of ethyl chloride vapor. This is
best done with a Gebaner tube as shown in the picture but
other containers which may be used are also in the market
(Fig. 54). If ampoules are used the neck should be filed
a little and then the entire neck end of the ampoule is in-
serted like a cork (air tight) into the rubber tube going into
the bottle. The outlet is opened and the neck of the ampoule
is snapped off by bending the tube. The ethyl chloride is
very volatile and at once rushes into the bottle. Wait a lit-
tle while for the drug to act. It generally acts fairly rap-
idly but may require a little time for diffusion through the
bottle and absorption into the animals' blood. How do the
symptoms compare with those produced by ether or chloro-
form? How long does it take to produce complete anesthe-
sia ! If you add oxygen as needed, how long can you keep up
this anesthesia with one dose of ethyl chloride? Do not give
more etliijl chloride than is absolutely necessary or you may
kill one or both of the animals. "Somnoform" or Brugg's
mixture may be used also if the drugs are available (they
can be bought from dental supply houses and are put up in
ampoules). Similarly ethyl bromide may be used. A *i<ill
quantity of this may be poured into the bottle through a
funnel. Save all animals used until next dav and observe if

V

any permanent injury has been done to them.

EXPERIMENT VIII.

The Closed Method of Anesthesia. For Ether, Chloroform,

Ethyl Chloride, Ethyl Bromide, (Nitrous Oxide),

' ' Somnof orm, " etc., with Oxygen. Student

Method. (Dogs or Cats.)

1. Observe carefully the construction of the apparatus
shown in Fig 116. Arrange the table for operative work
as shown in Fig. 117, but omit the ether bottle, substituting
therefor the apparatus shown in the illustration. Into the

122

EXPERIMENTAL PHARMACOLOGY

bottom of the large pan shown in Fig. 116 pour a layer of
strong (not saturated) sodium (or potassium) hydrate solu-
tion about three-fourths inch deep. The solution must not
be warm. Stretch the thin rubber bath cap air-tight over
the rim of the large pan as illustrated. Thereafter do not
iip set the pan nor splash out the solution. If the dog strug-

Wheei wrench

-Yoke

Oxyqen
tank

Fig. 116. Apparatus used for closed ether (ethyl chloride, chloroform, nitrous oxide,
etc.) anesthesia. A large, shallow, round cake pan covered by a thin bath cap holds
the vapors or gases. The animal breathes into and out of the pan through a spout.
Strong sodium (or potassium) hydrate solution (which must be cold) in the bottom of
the pan absorbs the CO 2 eliminated. A diagrammatic view of the pan as seen from above
is shown in Fig. 118. Oxygen is admitted as needed by the animal from the tank (or
from the apparatus shown in Figs. 176 and 177). Ether or chloroform or ethyl bromide
may be injected through the burette. Ethyl chloride can lie sprayed in through one of
the inlets. (See Journal of Laboratory and Clinical Medicine, 1916, ii, p. 94; also ibid.,
1916, ii, p. 145.)

gles this might occur, but such an accident is much more
likely to happen as the result of awkwardness. Etherize
the dog on the floor in the usual manner (Fig. 71). Then
place it quickly on the operating board, tie it down and
insert the tracheal cannula. The straight end of the can-

CLOSED METHOD OF ANESTHESIA

123

nula carries a short piece of rubber tubing and a screw
clamp. Close the clamp and insert the side tube of the can-
nula into the hole in the cork, which closes the large spout
from the pan. Bun enough oxygen into the pan to lift the
bath cap up about one inch above the top of the large pan.
From the burette it will probably be necessary to inject
about one or two cubic centimeters of ether into the pan be-
fore the anesthesia becomes deep enough. Do not be in
too much of a hurry to add this ether, for the anesthesia
should not be any deeper than is necessary. Hereafter the

Wash jar Ether bottle

injecting burette

Stethograph

Ligatures

Artificial
respiration

Key Electrodes

Pressure
bottle

Inductorium

Cord for jaws

outh rod Dog board

fan for
waste
materials

Cotton sponges

Sig. maqnet
Tbmbour

Cord forfrac^e^ Lias,

Kymo-
graph
drum

'Hemostats'

Hq -manometer

f- -N/VWVWVfcWV,

5 WWVWWV*/

^To timer-

Liqatures din. Tinner's snips Trephine

Fi^. 117. Arrangement of the apparatus on the table for performing an experiment.

anesthetist merely watches to keep a fair amount of oxygen
in the pan and at long intervals from one-half to one cubic
centimeter of ether may be injected if needed. The anes-
thesia should remain perfectly constant and regular if no
leaks are present in the apparatus. These are not difficult
to avoid. If the experiment is performed correctly the stu-
dent will be impressed with the ease and certainty with
which a perfect anesthesia can be maintained for long per-
iods of time. If too much ether (or other anesthetic) gets
into the pan open the screw clamp on the tracheal cannula

12-i

EXPERIMENTAL PHARMACOLOGY

and allow some of the vapor to escape. Then refill the pan
with oxygen. This method is new. Students are advised to
study it carefully. Is there any danger of the respiratory
medium becoming too moist ? Are any volatile poisons
given off in the breath that might accumulate in the breath-
ing space? Will the smaller percentage of nitrogen in the
air breathed bv the animal influence the anesthesia f Will

-Efher
inlet

Oxyqen
inlet

flanqe

Fig. 118. Diagrammatic view of the pan as seen from above.

the respiratory medium become too warm! Could you
counteract this! How is the ether excreted! How is it
absorbed and carried to the tissues! What combinations
does it form in the body ?

2. Arrange to record blood-pressure and respiration
(stethograph). Connect an injecting burette to the left
femoral vein. Isolate and ligate loosely (but do not clamp
or injure) the right femoral artery. Place some adrena-
line (1:10,000) solution in the burette. Or epinine solu-
tion (1:1000, Burroughs, Wellcome and Co.) may be used.

CLOSED METHOD OF ANESTHESIA

125

126

EXPERIMENTAL PHARMACOLOGY

Arrange all writing points on the drum and take a few
inches of normal record. How does this record of blood-
pressure and respiration compare with that obtained when
you used an ordinary ether bottle to maintain the
anesthesia?

3. While the anesthesia is moderately light but per-
fectly regular, inject just enough oxygen to run the animal
for about three minutes. Then with a screw clamp close
off the injecting (oxygen) tube and change the oxygen

Fig. 120. At the place marked "normal" the animal was breathing naturally. No
drug had been administered and the animal was lying quietly on the table. At the point
indicated some nitrous oxide was given. The respiration at once becomes deeper and
more rapid.

tank for a nitrous oxide tank. Open the screw clamp on
the injecting tube and run in as much N 2 as is possible
without stretching the bath cap. This should be perfectly
free to rise and fall and should not be under any tension.
If the cap is stretched the animal cannot breathe well for
the mechanical obstruction and may die. The drum runs
at a slow speed as the N 2 is run in. How does this affect
the blood-pressure and respiration? How does this com-
pare with the injection of a drug through the femoral vein?

CLOSED METHOD OF ANESTHESIA

What is the action of N 2 on the heart? Is the anesthesia
deepened?

4. After a sufficient time open the side clip from the pan
and empty out the mixed gases. Close the clip and run
in some fresh oxygen. Take some more normal record
and then from a Gebauer ethyl chloride tube inject through
the outlet tube of the pan a small amount of ethyl chloride.

Fig. 121. The animal was anesthetized with nitrous oxide. At the point indicated
a little ethyl chloride was given (in addition to the nitrous oxide). The much more
marked action of ethyl chloride on the blood-pressure and respiration is seen at once.

Do not give too much. How does this affect the blood-
pressure and respiration? Is the anesthesia deepened?
Which is the more powerful, ether or ethyl chloride?
Empty out the ethyl chloride and allow the anesthesia to
become fairly light.

5. Repeat No. 4, using ethyl bromide, "somnoform" or
Brugg's mixture instead of ethyl chloride. Do not give

128 EXPERIMENTAL PHARMACOLOGY

more titan one cubic centimeter of ethyl bromide (one-half
cubic centimeter is much safer). This is a powerful drug.

6. After records are obtained empty out the vapors,
open the screw clamp on the tracheal cannula and allow
the dog to get fresh air for some time to recover. (The
animal, of course, thus exhales the drugs into the open
air. )

7. When the animal recovers close the tracheal clamp
and let the anesthesia again become as regular as pos-
sible. Now through the burette inject into the pan one-
half cubic centimeter of chloroform. Do not give too much.
Obtain a record and then empty out the vapor as before.
How does this record compare with those obtained with
the other drugs ! What conclusions can you draw concern-
ing chloroform? What class of physicians make most use
of chloroform?

Can you use the closed method for anesthesia when the
chest is opened? This is a good point for the student to
consider. Does this method present any advantages over
the use of an ordinary ether bottle? What are the relative
disadvantages ?

8. Put about one cubic centimeter of chloroform into a
ciood dental syringe carrying a small short needle. Now
lift up the right femoral artery on an aneurism needle an 1
at the same time let an assistant press down on the cor-
responding vein to shut off its return flow. Now with
great care slip the syringe needle endwise into the lumen
of the artery. Loosen the tension on the artery a little
and as the blood again flows through carefully inject the
chloroform. Feel of the leg. Is there produced a pro-
found change in the tissues! If not, repeat the injection
into the other femoral artery.

9. Kill the dog by asphyxia. Open the abdomen and
dissect out and examine the spleen, pancreas and left kid-
ney. To what is the spleen attached ? Place it inside an

INTRATRACHEAL IX.SU F F LATION

129

oncometer and close the abdomen with heinostats. Could
you do this in a living dog I Remove the oncometer and
put away all apparatus. Do not forget to wash out the
tubing connecting the carotid to the manometer.

EXPERIMENT IX.
Intratracheal Insufflation.

1. Study carefully the principles involved in the con-
struction of the apparatus shown in Fig. 122. A constant

Fig. 122. Apparatus for intratracheal insufflation. The tip of the catheter should
toe cut off just back of the "eye." Any similar sized rubber tube may be used instead
of the catheter. The outer diameter of the tube should be about one-half (or a little
Jess than) that of the inner diameter of the trachea.

current of air passes into the tube at the extreme right of
the picture. By turning the small lever on the side of the
ether valve, part or all (or none) of the air can be made to
pass over the ether and then out through the rubber
catheter at the left. (The cap and spout on the top of the

130

EXPERIMENTAL PHARMACOLOGY

ether valve are not used in this experiment. The opening
up into the cap should be closed with a cork.) Any ordi-
nary ether bottle with a side pass as shown in Fig. 107 may
be used for this purpose instead of the valve here shown.
Just to the left of the ether bottle is a smaller bottle con-
taining mercury. The cork in this bottle is perforated by

-Flexible
Breathing
Bay

Metallic muzzle
with rubber cushion

Fig. 123. Schematic arrangement of an apparatus for administering nitrous oxide
(ether, etc.) to an animal. The gas or vapor (ether; is washed (by means of the air
pump) through NaOH solution (to remove CO 2 ) and through HoSO* (to remove watery
vapor). Oxygen is admitted as needed by the animal. The animal breathes into and
out of the ventilated bag.

two holes through one of which a tube from the main air
way dips down just below the surface of the mercury.
This tube can be raised or lowered and thus serves as an
adjustable pop-off valve to regulate the pressure if it be-
comes too great. To the left of the mercury bottle a mer-
cury manometer and scale are placed. The manometer

ACTION OF CARBON DIOXIDE

131

132 EXPERIMENTAL PHARMACOLOGY

connects with the main air way and when in use the mer-
cury manometer should record a pressure of about twenty
millimeters.

For an average sized dog the catheter may have an out-
side diameter of about three-sixteenths or one-fourth inch.
The catheter is slipped into the trachea down to its bifur-
cation and then withdrawn a little. The animal should be
etherized in the usual manner and then the catheter may
be introduced through the larynx or through the tracheal
cannula. The air and ether vapor blown in through the
catheter escapes again from the lungs between the outer
wall of the catheter and the inner Avail of the trachea.
As a rule, the dog will keep up shallow respiratory move-
ments while the anesthesia is carried on by this method.
Would it be advisable to turn the air current off for a
few seconds at intervals of one or two minutes'? It is ad-
visable for the student to practice for some time with this
method before attempting severe operations while using
it. Meltzer, Auer and their associates at the Rockefel-
ler Institute have extensively used and developed this
method, while from the University of Minnesota Hirsch-
felder has reported excellent results with it in ordinary
student experiments. Can you repeat these results ? Could
this method be used when the chest is opened? What pre-
cautions would you then take ? Could you use the method to
record changes in the volume of the lungs (see Figs. 187
and 257, also consult Experiments XXIX and LXX).

What are the advantages of this method ? What are
the disadvantages I This method may be used in some of
the later experiments. It is often very convenient for
maintaining a regular anesthesia.

This method has been much used for intrathoracic sur-
gery, etc., and several different forms of apparatus for
carrying on intratracheal insufflation have been devised
and used. It is very desirable for the student to become
familiar with the principles involved, and if possible, to
have some experience in using the method.

GENERAL ACTION OF ALCOHOL 133

EXPERIMENT X.

Alcohol. (Frog: Central Nervous System, Heart and Vago-

sympathetic Nerve.)

1. Solutions of alcohol for injections or administration
by stomach should, if possible, be made up from absolute
alcohol. For the technic of injecting solutions into the
lymph spaces of frogs see Figs. 125 and 126. Make up
nine cubic centimeters of alcohol 66 2/3 per cent strong.
Into the anterior lymph sac of a frog inject either from a
glass injecting pipette (Fig 127) or with a hypodermic
syringe (Fig. 126) one cubic centimeter of the alcohol so-
lution. Do not injure the frog in any w r ay in holding it,
etc. Place the animal in a battery jar on some moist cot-
ton and observe its actions closely. Touch it from time
to time to observe the condition of the reflexes. Does the
animal show any symptoms from the local irritation of
the drug at the point of injection? Do these obscure the
later systemic effects which come on after absorption of
the drug by the circulation? How do the symptoms pro-
duced by alcohol compare with those produced by ether or
chloroform or nitrous oxide? What organs are affected
by alcohol as shown by this experiment? Does the frog
become completely narcotized? If so, how long does the
condition last? Does the animal recover completely?
Place it in a battery jar on moist cotton for several hours
to allow of recovery. The beating of the heart can be
seen through the chest wall in front.

2. Pith a frog and dissect out the vagus nerve. Place
the electrodes so that the nerve can be stimulated without
disturbing the animal and arrange for taking a heart trac-
ing. Take two inches of normal tracing and then stimulate
the vagus nerve. Do you get a normal inhibition 1 ? (Do
not stimulate the nerve too long or too often or you will
w^ear it out. You can not then test the action of the drug

134

EXPERIMENTAL PHARMACOLOGY

on the inhibitory mechanism.) It is usually advisable to
take two records of normal vagus inhibition.

Now start a second round of the tracing and when the
new record lacks about one inch of being directly over

Fig. 125.

Fig. 126.

Fig. 125. Injection of drug solutions into the anterior lymph sac of a frog. The
narrow point of the injecting pipette is passed into the mouth, and the tongue (which
is attached to the front part of the lower jaw) is pushed to one side. The point of the
pipette is quickly but gently forced through the muscles in the floor of the mouth. The
point will then be felt just beneath the skin over the under jaw. The pipette is now
slipped down toward the chest. The skin is attached to the underlying muscles across
the sternum but the point is passed through this attachment and into the lymph space
in front of the abdomen. The finger is taken off of the upper end of the pipette and
the solution is allowed to run slowly into the anterior lymph sac. Do not injure the
frog by squeezing it.

Fig. 126. Injection of solutions into the anterior lymph sac with a small hypodermic
syringe.

the first vagus inhibition record, drop on the heart about
ten drops of ten per cent alcohol. How does this affect
the beat of the organ? At the moment when the record

ACTION OF ALCOHOL 135

reaches a place directly over the first inhibition record,
stimulate the vagus nerve again. Do you now get an in-
hibition, or has the drug paralyzed some part of the local
inhibitory apparatus? Drop on more alcohol and again
stimulate the nerve over the second inhibitory record. The
total length of the record from left to right should be
about seven or eight inches with a moderate drum speed.
About five or six rounds of tracing (in a series from the

w^

Fig. 127. Injecting pipette made of glass. About 2/3 natural size.

bottom of the drum upwards) should be made. Add the
alcohol freely to the heart during the second and third
rounds, but on the later rounds, if necessary, use thirty or
forty per cent alcohol. What is the general action of alco-
hol on the frog's heart as shown by your tracing? Does
alcohol either paralyze or stimulate the inhibitory appa-
ratus'? How does this compare with ether or chloroform 1 ?

EXPERIMENT XI.

Alcohol. (Turtle: Heart and Vagus Nerve.)

1. Pith a turtle and fasten it down to the turtle board.
Expose the heart and take a heart tracing (normal) includ-
ing two or three vagus inhibitory records. Then apply
twenty per cent alcohol to the heart as was done in Experi-
ment X, and again stimulate the nerve. What effect does
the drug have on the local inhibitory apparatus'? If the
heart muscle alone should be stimulated by the drug would
the inhibition be greater or less when the nerve was stim-
ulated after the drug was applied? How would the inhibi-
tion be affected if the muscle alone were depressed?

136 EXPERIMENTAL PHARMACOLOGY

EXPERIMENT XII.

Ethyl Alcohol, Brandy, Whiskey, Wine, Methyl Alcohol,
Amyl Alcohol. (Dog: Blood-pressure, Respiration,

Esophagus.)

1. Etherize a dog and arrange for blood-pressure and
respiratory tracings. Connect injecting burettes to both
femoral veins. Isolate and ligate loosely both vagi, using
great care not to injure them in the dissections or manip-
ulation or by allowing a part of either nerve to lie outside
the wound and to become so much dried up in the air that
impulses can no longer be conducted over the nerve fibers.

Xow pull the trachea to the left side and pick up the
esophagus (pulling it toward the right) on a large aneu-
rism needle. Make a longitudinal incision about three-
fourths of an inch long in the side of the esophagus a little
way below the larynx. Xow pass through this incision into
the lumen of the esophagus the finger cot on the end of
the catheter as shown in Fig. 128. The end of the cathe-
ter should pass down the esophagus to a point about one
or two inches above the cardiac sphincter. A ligature is
then tied around the catheter at the esophagus incision
tight enough to prevent the catheter from slipping out
and with a hemostat the ligature ends are clamped (close
to the esophagus) to the neck tissues at the side of the
wound. The burette is now filled about half full of wa-
ter and the catheter is moved in and out a little to get
the water to run down into the finger cot. It /> important
for the cot to be trell filled iritli the water. Place the cork
in the burette and connect the tube in the cork to a medium
sized tambour which is adjusted for a fairly large magnifi-
cation. Arrange this tambour to write at the top of your
records; next below this should be the blood-pressure
(manometer) record, below this the respiration, and at
the bottom should be the base line marked bv a signal

RECORDING LSOPHACHAL CONTRA' TIONS

137

magnet which records five or ten second intervals. If a
metronome or Harvard clock is used, shorter time inter-
vals must be employed. This may call for a faster drum
spe<-<l. The rate should, however, be fairly slow. When

Elastic rubber
band to attach

cot fa
catheter

Fig. 128. Arrangement of apparatus for recording esophageal contractions.

all adjustments are made start the drum and record one
or two inches of normal tracing-. Then with a medium
strength tetanizing current stimulate the right vamis nerve
for one-half second. Wait till the records all return to

138

EXPERIMENTAL PHARMACOLOGY

normal and then stop the drum. Does the vagus stimula-
tion stop the heart? How does it affect the respiration?
Did you get a record from the esophagus? If so, how do
you explain the cause of this last record ? Could the record
have been caused by the respiratory movements? Could

' .j

Fig. 129. Four esophageal contractions, blood-pressure and respiration. The nerve was
stimulated (for a moment only) four times by a tetanizing current.

ACTION OF ALCOHOL 139

yon avoid this possibility in any way? Is the superior
laryngeal nerve concerned in any way with your observa-
tions! Stimulate this nerve independently and study the
results.

Place adrenaline solution in one injecting burette and
twenty per cent alcohol (made from absolute alcohol) in
the other. Start the drum and when about one inch of
satisfactory normal tracing has been taken inject two cubic
centimeters of the alcohol solution. The blood-pressure
and respiration are slightly affected. This gives you a fair
basis to estimate the resistance of the animal to the alco-
hol and to judge what size the next dose should be. If the

Fig. 130. Harvard membrane manometer.

dog is small or very susceptible the dosage must be re-
duced. When the records have returned to normal inject
as large a dose as you think the animal can safely stand
and yet make a good recovery. This will likely range
between five and fifteen cubic centimeters but may be much
larger in many cases. Secure two or three good tracings
from alcohol and then again stimulate one vagus nerve for
a brief period. When the records return to normal stop
the drum. How do the records obtained now compare
with those made before the drug was given? If the ani-
mal seems very weak or about to die inject one-half cubic
centimeter of adrenaline.

2. Empty the alcohol out of the burette (give it back to

140 EXPERIMENTAL PHARMACOLOGY

the instructor) and fill the burette with brandy. What is
the percentage of alcohol in brandy? How is brandy made?
Start the drum and inject what you believe will be a fair
sized dose for vour animal. Do this two or three times

/

and secure satisfactory tracings. How do these tracings
compare with those obtained from alcohol?

3. Replace the brandy in the burette with whiskey.
What is the percentage of alcohol in whiskey? Inject a
fair sized dose and secure satisfactory tracings. This may
be done two or three times if the animal is sufficiently re-
sistant. But if the animal is weak, then the fewest injec-
tions possible should be given to secure typical tracings
showing the action of each drug.

4. Substitute wine for the whiskey in the burette. How
much alcohol is there in wine? What else is contained in
wine? Inject one or two cubic centimeters and see how
this affects the animal. Use larger doses if you can safely
do so. How do the records obtained compare with those
from alcohol, brandy and whiskey? How do you explain
this? Inject some adrenaline and then allow the animal
to recover.

5. Fill the burette with twenty per cent methyl alcohol.
Inject one cubic centimeter and secure a record. How
does the toxicity of this drug compare with that of ethyl
alcohol? If it appears safe, a larger dose may be injected
to secure satisfactory tracings. Does the alcohol which
you have injected affect the anesthesia in any Avay?

6. Substitute a ten per cent mixture (shake well) oi ?
amyl alcohol and water for the methyl alcohol in the bu-
rette. Inject one-half cubic centimeter and secure trac-
ings. What can you say about the toxicity of this body .'
Kill the animal with amyl alcohol. Which stops first, the
heart or the respiration? Give some adrenaline, massage
the heart and give artificial respiration to see if you can
revive the animal. It is important for the student to learn

PRACTICE DISSECTIONS

141

the methods used for reviving animals when they are near
death, especially from threatened death under an anes-
thetic.

Suspended
pressure bottle

Finger cot or
rubber dam

Glass tube, or
Harvard muscle
warmer

Fig. 131. Arrangement of apparatus which may be used as a membrane manometer.

7. If time permits after the animal is dead, open the
chest by a median longitudinal incision, sawing the ster-

Fig. 133. Dissection showing the vessels and nerves in the neck and upper part of
the chest in a dog. (Modified from Schmiedeberg.) 1. Rt. inferior (recurrent) laryngeal
nerve. 2. Vago-sympathetic nerve. 3. Phrenic nerve. 4. Vertebral nerve. 5. Rt. in-
ferior (recurrent) laryngeal nerve. 6. Inferior cervical ganglion. 7. Cervical sympa-
thetic nerve. 8. First thoracic ganglion. 9. Superior cardiac nerve. 10. Inferior
cardiac nerve. 11. Vagus trunk. 12. External jugular vein. 13. Thyroid gland. 14.
Internal jugular vein. 15. Subclavian artery. 16. Carotid artery. 17. Brachial plexus.

PRACTICE DISSECTIONS 143

num open endwise, and make the following observations :
Isolate and trace out both phrenic nerves. Trace the
vago-sympathetic trunks from the neck region down into
the chest. Follow the right nerve closely in the tissues at
the apex of the chest. At this point isolate the subclavian
vein and tie two ligatures tiglitly around the vessel. Be
sure tlie ligatures are tied iigl/itly enough not to slip off.
Cut the vein between the ligatures and follow the nerve
down behind the vein to the subclavian artery. (See Figs.
133 and 184.) Isolate the annulus Vieussenii (ansa sub-
clavia) and pick up the fibers that pass off toward the
heart. Part of these fibers are from the vagus proper and
if stimulated in the living animal will S!OW T or weaken (or
stop) the beating of the heart. A few of the remaining
fibers are from the sympathetic system (Figs. 148 and 318)
and when stimulated in the living animal will cause the
heart to beat faster (accelerators) or stronger (augmen-
tors). Could you perform a dissection like this in a living
animal? What would be the most likely causes of failure?
How could you avoid these? Open the pericardium, ex-
amine the auricles and ventricles. Isolate the left pul-
monary artery and pass a ligature beneath it. Hunt for
the thoracic duct. Where is it located in the chest? What
does it resemble? With what might you confuse it? The
writer has seen students look in the wrong side of the
chest for the duct. What criticism would you offer in
such a case?

EXPERIMENT XIII.

Whiskey or Brandy. (Reaction Time.)

1. Observe carefully the arrangement of the apparatus
shown in Fig. 134. The subject of the experiment holds
down (closed) the handle of key A; key B remains open.
The writing point of the signal magnet does not move.

144

EXPERIMENTAL PHARMACOLOGY

The operator holds key B. The drum is started off at a
fast rate. While the subject watches the signal magnet
closely the operator suddenly closes key B. The writing
point of the signal magnet at once goes down. Instantly
as the subject sees this he opens key A. The drum keeps
running, the operator opens key B and the subject again
closes key A. The operator now closes key B and the sub-

K Key A

Fig. 134. Arrangement of apparatus for recording reaction time for sight.

ject instantly opens key A. In this manner about twenty
or thirty normal records are taken. With a vibrating
tuning fork (Fig. 136) beating fiftieths or hundredths of
a second, a time tracing (three or four may be needed) is
now run around the drum. With a pair of dividers or a
rule the average length of time which it takes the subject

EFFECT OF ALCOHOL ON REACTION TIME

L45

to respond to a sight stimulus, i. e., liis normal reaction
time for sight, is estimated.

The subject now takes by stomach five or ten cubic cen-
timeters of whiskey or brandy well diluted with water. A

Fig. 135. Simple key.

little sugar may be added to the water in order to in-
duce the subject to take the drug more readily. After fif-
teen minutes the student's reaction time for sight is again

Replaceable fort

Fig. 136. Electric tuning fork.

taken. Is there any change! How do you account for

this? "\Vhat portions of the nervous system are involved?

2. Arrange a telephone in the secondary circuit of an in-

146

EXPERIMENTAL PHARMACOLOGY

duction coil as shown in Fig. 137. The subject holds the
telephone to his ear and listens (with closed eyes) for
the click of the closing of key B by the operator. At the
instant the sound is heard the subject opens key A. The

KeyB

Fig. 137. Arrangement of apparatus for recording reaction time for hearing.

reaction time for sound is thus recorded on the drum. Re-
peat this twenty or thirty times and estimate from the
tuning fork record the average length of time required for
the reaction.

The subject now takes some whiskey or brandy (or wine)
as indicated above (1) and after fifteen minutes his reac-

ALCOHOL, WHISKEY, BKANDY, WINE

147

tion time is again taken. Is there any change? What
parts of the nervous system are concerned?

3. In a similar manner the effect of alcoholic drinks on
the reaction time for touch may be recorded by allow-
ing the subject to place his finger under key B in such a
manner that he can just feel the closing of the key by the
operator. The subject then opens key A.

4. If time peTmits, the reaction time for sight and sound
may be taken again after three or four hours. Compare
these results with the normals and with those obtained
fifteen minutes after the drug was taken. What conclu-
sions can vou draw?

EXPERIMENT XIV.

Alcohol, Whiskey, Brandy, Wine. (Dog or Cat: Myocar-
diographic Tracings, Cardiac Sympathetic Nerves.)

1. Arrange for a perfectly constant and reliable source
of artificial respiration before beginning the experiment.

Fig. 138. Box for anesthetizing cats.

If a cat is used, all the cannulas for vessels and the tra-
chea must be much smaller than those used for dogs.

Etherize the animal in the usual fashion. If a cat is
used it may be etherized in a special box (Fig. 138) or in

148

EXPERIMENTAL PHARMACOLOGY

a bell jar (Fig. 139) or in an ordinary earthenware or
glass jar covered with a glass plate. A tin bread box
serves very well, especially if it has a glass window. Cot-
ton may be placed in the neck of the bell jar and the
ether dropped in on this. If a box like Fig. 138 is used, the
animal's head is left out when the lid is closed and a towel
on which the ether is dropped is placed over the cat's
head. Cotton saturated with ether can be dropped in the
earthenware jar or bread box.

Fig. 139.

Fig. 140.

Fig. 139. Bell-jar as used for anesthetizing cats.

Fig. 140. Glass or earthenware jar covered by a glass plate. Used for anesthetizing

cats, rabbits, etc.

Quickly tie the animal down on the operating board and
arrange to take a blood-pressure tracing. Connect inject-
ing burettes to both femoral veins. Record the normal
rectal temperature. By a median incision open the chest.
In a cat this is best done with tinner's snips (Fig. 98).
(See Fig. 105, also read Experiment V, 6, page 108.) When
the sterum is divided throughout its length pull the chest

MYOCARDIOGRAPH

149

Supporting rod

Rubber
digphraqm

Adjustable

attachment

Eye5 for
levers to heart-

Rubber tube
to recording

tambour.

iiSlS^

Adjustable
tambour

ig. 141. Myocardiograph.

150

EXPERIMENTAL PHARMACOLOGY

open, tie four strong ligatures into the margins of the sev-
ered walls as shown in Fig. 106, and with these ligatures tie
the chest firmly, leaving an opening about three or three
and one-half inches wide in a dog. This opening will be
smaller in a cat. Open the pericardium and stitch it to
the chest walls.

X 7o recording
tambour

Csrdi'ometer

Pin hook to fasten into
ventricle

Fig. 142. Cardiometer arranged for use as a myocardiograph. The pin is hooked
into the heart muscle and the cardiometer is held in a clamp. The beating of the heart
moves the membrane in and out. A tambour is used for recording.

Various forms- of instruments are used to record heart
tracings directly from the heart. One is shown in Fig.
141. If you have such an instrument, suspend it in a clamp
from a stand over the heart. By two stitches made with a
needle in the upper and lower ends of the left ventricle

RECORDING HEART TRACINGS

151

fasten the lower ends of the two levers firmly to the heart.
As the ventricle beats air will be forced in and out of the
tambour on the apparatus. With rubber tubing connect
the apparatus to a medium sized tambour which records be-
low the blood-pressure on the drum. Cushny has devised
a myocardiograph which may be used to advantage. (Eber-
bach and Son Company, Ann Arbor, Mich.) With this in-
strument the drum must be brought to the side of the
animal. (See Fig. 317.)

If no special apparatus is available, then a pin hook can

To tambour

-Thistle tube

Ca rdiom eter

Elastic rubber
dam

Fig. 143. Cardiometer made from a large thistle tube. A hollow rubber ball with
an opening cut in one side and a tube in the other may be made into a cardiometer
by cementing a perforated rubber membrane over the opening in the side of the ball.

be attached to the heart. A string is tied to the pin and
passed over pulleys to an ordinary (weighted) frog heart
lever which writes on the drum. Or a rubber membrane
(in the center of which a screw is attached, see Fig. 374) is
tied over a cardiometer (Fig. 142) and the string attached
to the heart by the pin hook is fastened to the screAv in the
membrane. The cardiometer is held in a clamp and con-
nected with a recording tambour. Another method of re-
cording heart tracings is shown in Fig. 144.

When all adjustments are made place adrenaline solu-

152

EXPERIMENTAL PHARMACOLOGY

tion in one burette and thirty per cent alcohol in the other.
Start the drum with a medium speed and take a short nor-
mal record. // even/thing is satisfactory then inject two
cubic centimeters of alcohol if the animal is a dog, or one-
half cubic centimeter if vou have a cat. From the results

Weights ^ari

Ventricular lever
Artificidl respiration

Fig. 144. Arrangement of apparatus for recording the movements of one auricle
and one ventricle. The heart is held in a special holder (Fig. 145) here but sometimes
the pericardium is slit open and the edges are stitched to the sides of the chest so that
the heart lies in a sort of hammock.

of this first dose you can estimate about what sized doses
the animal will be able to overcome later. This will vary
with each experiment and the student should early learn
to estimate doses of drugs of low toxicity. AVith very pois-

CARDIOGRAPHIC TRACINGS

153

onous drugs the dose must be given much more accurately.
How does this first dose affect the heart tracing? Increase
the dose and secure marked effects from the heart. Ob-
serve the appearance of the organ while the drug is acting.
The respiratory movements of the lungs may disturb your
cardiac apparatus and show notches at the top and bottom
of your heart tracing. To check this reduce the respira-
tory movements as much as possible by shutting down the
amount of air blown into the lungs. Note carefully any

Right bowl

Fig. 145. Special heart holder to keep the heart from moving with the lungs as
they contract and expand from the artificial respiration.

effect this may have on blood-pressure. Watch your
anesthesia carefully and do not give too much ether. Make
one injection (y 2 c.c. for a dog, 140.0. for a cat) of adrena-
line and obtain a tracing showing the action of this drug
on the heart.

2. Now obtain tracings showing the action of whiskey,
brandy and wine. Can you use beer or champagne for in-
travenous injections? On what do you base your conclu-
sions? Record the rectal temperature again and com-

154

EXPERIMENTAL PHARMACOLOGY

o

r

in

Fig. 146. Heart levers for dogs. The writing lever is made of heavy aluminum
wire which is coiled around a small wire nail to form the hinge. The nail is driven
tightly into a small hole drilled in the end of a 3/16 inch brass rod.

Medulla

oblongata
N.XI

N.I

Postganglionic fibers

are dotted thus

Accessory n.
hi trapezium

Spinal
medulla
(cord)

Kami

communican-
tes going to
5ymp. gang,
(preqanglionic)
Ansa

subclavia
(Annulus of
Vieussens)r

Thoracic 3
nerves

Electrodes
(Acceleration, or

augmentation of heart.)

N.IX.
f . /\

-Juqular ganglion (Cang. of the root)

Depressor (Fall in pressure or slowing of heart.)
(Sensory) separate nerve in rabbit and opossum

Nodosum ganglion (Gang, of the trunk) * Hunf
Inhibitory cranial autonomic fibers

Harrington)

Superior cervical ganglion
Descending sympathetic fibers in cord
Cervical vago- sympathetic trunk

^Electrodes (slowing or stoppage of
5ubclavian heart. Augmentation in some

animals.)
Aortic arch

Inferior
cervical
gang

First thoracic gang/ion
(Stellate)

Fig. 147. Schematic representation of the innervation of the heart.

SYMPATHETIC CARDIAC SERVES

155

pare this reading with the former one. What conclusions
can yon draw?

3. If the animal is in fair condition, isolate the right
subclavian vein at the apex of the chest (see Figs. 133 and
184). Tie tightly two ligatures around the vein and sec-
tion the vessel between the ligatures. Pick up the ansa
subclavia (annulus Vieussenii) and stimulate some of the

Depressor nerve
(running with
the vagus trunk
on the right)

Union between
middle cervical
ganglion and
vagus nerve

Fibers from
spinal cord
to stellate
ganglion

Right
stellate
(inf. cervical)
ganglion

Communicating
branches between
the vagus and the
stellate ganglion

-Vagus trunks-ff
Ceik * - IK

.
athetic cords

Depressor nerves
Separate on
the left)

Middle cervical
ganglia

Recur rent-i

laryngeal

nerves

Ansa
subclavia

Cardiac
fibers

Union between
middle cervical
ganglion and
vagus nerve

Left stellate
inf. cervical)
^ganglion

Fibers from
spinal cord to
stellate gang.

t>
Depressor nerve

Cardiac nerves

from the
stellate ganglion

Fig. 148. The innervaticm of the heart in the cat. (After Boehm. )

small fibers passing from the ganglia or the anterior loop
of the annulus toward the heart. These will probably be
derived from the vagus and the heart will then be slowed.
Pick up some others of the small fibers lower down and
stimulate them. You will probably find a fiber which does
not cause any slowing of the heart and no immediate effect
may follow its stimulation. But if you get a pure sympa-
thetic cardiac fiber, stimulation of this nerve will, after a

EXPERIMENTAL PHARMACOLOGY

II

3'5>

T3

S.2

g

' CC

o

II
~ rt

<

*- ^ in

03 nj o

I- U

"o iJ"3

'-l

J2 60 ~

bo c rt

07: o

ANTISEPTIC ACTION OF ALCOHOL

157

very perceptible latent period, cause a change in the heart
beat either producing an acceleration of the rate or in-
creasing the strength of the beat (augmentor effect). If
possible, secure tracings showing these effects on the heart.
How do these records compare with the action of adrena-
line on the heart? Do you know of any other drugs that
act on the heart similarly to adrenaline? Watch for these
later in your course. Kill the animal by asphyxia.

EXPERIMENT XV.
Antiseptic Action of Alcohol.

1. Obtain four fermentation tubes (Fig. 150). Place a
cake of yeast in two hundred cubic centimeters of water,

Fig. 150. Fermentation tube.

add some glucose and shake up the mixture thoroughly.
Pour out enough of the mixture to fill one fermentation
tube, add sufficient absolute alcohol to the mixture to make

158 EXPERIMENTAL PHARMACOLOGY

a one per cent solution and fill the tube. Similarly fill the
other three tubes with the mixture, but place in the second
tube ten per cent of alcohol, in the third, forty per cent,
and in the fourth, seventy per cent. Be sure the air is all
out of the tops of the tubes. Place these in an incubator
at 37 degrees Centigrade (or in a warm room) until the
next day. Then examine the tubes and record any obser-
vations you may make. A culture of colon bacilli may be
used instead of yeast.

EXPERIMENT XVI.

Alcohol, Brandy, Urethane, Chloral. (Dog: Blood-pressure,
Respiration, Cerebrospinal Fluid, Kidney or Spleen.)

1. Etherize a dog and arrange for blood-pressure and
respiratory tracings. Provide two injecting burettes (one
containing adrenaline, the other twenty per cent alcohol).
Turn the dog's head to the left, trephine the skull (see
Figs. 97 and 100; also read Experiment V, 2, page 103).
Make the trephine opening in the skull as carefully as pos-
sible so the edges will be smooth and regular. With small
scissors cut away the dura mater over the area covered
by the opening. Do not injure the brain and try to avoid
all hemorrhage. NOAV place a perforated (rubber) cork
tightly in the opening so that solutions cannot leak around
it. The cork must not press on tlie brain. The perfora-
tion in the cork carries a small (5/16 inch) glass tube.
This tube is filled Avith salt solution and then connected
by rubber tubing to a small water manometer (Fig. 151).
From the funnel the manometer and tubing are filled with
normal salt solution, the glass tube in the cork is filled
with salt solution from a pipette, and the rubber tube is
slipped over the glass tube. This makes a complete fluid
connection between the cerebrospinal fluid in the subdural
spaces and the meniscus of the salt solution in the left
hand limb of the manometer. For adjustments in pres-

RECORDING CEREBROSPINAL, PRESSURE

159

sure, the manometer can be moved up and down on the
stand. The dog's head can now be rotated back to the
original position and the pin put through between the
teeth. Mark on the glass (or record from the scale) the
level of the meniscus.

Adjust the apparatus to record blood-pressure and res-
piration. If you have a small and very sensitive tambour
you may also connect this to the top of the manometer tube

Fig. 151. Arrangement of apparatus for recording the pressure of the cerebrospinal fluid.

(left) and try to record changes in the pressure of the
cerebrospinal fluid. Otherwise simply observe and write
down the variations which the manometer shows. Becht at
the University of Chicago records intracranial pressure
by means of a long glass tube inclined upward at a slight
angle from the horizontal. In this way a slight increase in
pressure moves the fluid in the small bore of the glass
tube.

160

EXPERIMENTAL PHARMACOLOGY

2. With a medium tetanizing current stimulate the right
vagus nerve for a second or so. How does this affect the
respiration, blood-pressure, and cerebrospinal pressure?
What mechanical factors are involved ? Xow inject one-
half cubic centimeter of adrenaline and repeat your obser-
vations. What mechanical factors are concerned?

When the records return to normal inject two cubic cen-

Fig. 152. Spleen oncometer for dogs. A little less than natural size.

timeters of alcohol. Note the effect on the circulation and
respiration and then estimate how much larger dose you
can safely inject. When the records return to the nor-
mal inject more alcohol and watch carefully for changes in
the cerebrospinal fluid. It may be necessary to inject three
or four times to produce any results. "What do you ob-
serve! How do you explain this? Stop the drum and
wait ten minutes to allow the animal to recover and to see

ADJUSTMENT OF ONCOMETER

161

if other changes occur in the pressure of the cerebrospinal
fluid. The anesthesia should be as nearly perfect as pos-
sible while the above parts of the experiment are being
performed.

3. With a median longitudinal incision now open the
abdomen and place hemostats at each side on the edges of
the wound. Pull upward and outward on these (two) hem-
ostats and expose the viscera. Do not manipulate these
organs any more than you can help or the animal may pass
into a condition of shock. Keep Hie Intestines inside the
abdomen. If you have a spleen oncometer (Figs. 152 and
153) this is easiest for a beginner to adjust. Gently pull

Fig. 153. Spleen oncometer for dogs. About one-half natural size.

the spleen forward and fit it into the oncometer, close the
instrument and place it back into the abdomen, attach the
tube for the tambour and close the abdomen air tight with
three or four hemostats. (Sew it up if you do not have
hemostats.) The abdominal wound must be closed tightly
and there should be no internal hemorrhage. If you have
a kidney oncometer (Figs. 154 and 156) instead of one for
the spleen, then refer to Fig. 158, and in the manner there
shown expose the left kidney. Do not injure the renal ves-
sels but gently lift up the kidney and slip it into the on-
cometer. Carefully avoid catching loops of the intestines
or a piece of the omentum in the oncometer. Close the lid
and fasten the latches (or put on the rubber band) and
connect the tube for the tambour. Carefully replace the

162

EXPERIMENTAL PHARMACOLOGY

Fig. 154. Kidney oncometer (natural size for medium sized dogs). Front view. Made

of sheet brass.

Fig. 155. Rear view of same oncometer shown in Fig. 154.

OISTCOMETERS

163

]''ig. 156. Front view of kidney oncometer made of a round metal pill or ointment box.

Closed by a rubber band.

1'ig. 157. View showing the oncometer partly open. This oncometer can also be used

well for a loop of the intestine.

164

EXPERIMENTAL PHARMACOLOGY

intestines around the kidney and close the abdominal
wound tightly.

The recording tambour should have a fairly large bowl
and the magnification should be large. Adjust all writing

Fig. 158. Dissection showing the method of exposing the kidney from a median
incision. Do not cut across the side of the abdominal wall. When the kidney is placed
inside the oncometer the abdomen is closed air tight with hemostats. LK, left kidney.
S, stomach. RA, renal artery. K.V , renal vein. L, ureter. /, intestine.

ADJUSTMENT OF APPARATUS

165

points on the drum, recording 1 from above downward, on-
cometer, blood-pressure, respiration, base line and time
signal. The writing points slwuld not be in a straight line
perpendicularly but should be so adjusted that each two
adjacent pointers can just pass each other.

2plre,

Lea

-F>7?ff3ffee.

Fig. 159. Arrangement of apparatus for making several records at the same time
on the drum. The proper adjustment of these tambours, etc., is one of the most dif-
ficult parts of the whole experiment. Suitable stands which can be placed close to-
gether at the bottom aid greatly. (See chapter on shop work.)

4. Start the drum and inject one-half cubic centimeter
of adrenaline. Make a small cross just under the position
of each record at the moment of injecting the drug. Do
you get a satisfactory record? The purpose of this in-
jection is to show you what a good spleen or kidney volume
tracing should look like.

Consult the instructor to get his opinion of your record.

166 EXPERIMENTAL PHARMACOLOGY

Now stimulate one vagus nerve and record the result.
When all the pointers return to normal inject a fair sized
dose of alcohol. Does this affect the blood-pressure? How
does the spleen or kidney tracing obtained now compare
with the one produced by adrenaline ? How do you explain
this? What mechanical factors are involved? Inject an-
other dose of adrenaline and see if you can determine two
phases to the adrenaline action. How do you explain this?
Now obtain tracings showing the action of brandy, ure-
thane (ten per cent solution, two cubic centimeters for the
first injection), and chloral (four per cent solution, one
cubic centimeter for the first injection). The oncometer
tracing is liable to become unsatisfactory after three or
four records have been obtained from it. Can you deter-
mine what this is due to! (See Fig. 160.) How do ure-
thane and chloral affect the blood-pressure and respira-
tion? Which is the more active drug? Kill the animal
by closing off the respiration. Do you get an oncometer
tracing? How is the blood-pressure affected?

5. If time permits, carry out the following dissections :
Open the chest by a median longitudinal incision and pull
the heart (pericardium) over to the right side. Deep down
in the chest (behind the diaphragm as it arches upward)
and a little way latterly from the median line you will find
the esophagus and the aorta. These can be traced down
from the upper part of the chest and from the heart. Look
for the vagus trunks on the esophagus (Fig. 161). Be-
neath the pleura at the side of the spinal column you can
find the main branches of the thoracic sympathetic. Pick
these up and trace them down behind the diaphragm.
Open the abdomen, divide the diaphragm, and pull the
stomach and liver to the right. Can you trace the passage
of these sympathetic fibers from the chest down into the
abdomen? Observe carefully the exact position which the
fibers occupy and see into what kind of a structure thev
pass. If the stomach, liver and diaphragm were in their

\

\

Fig. loO. Illustration showing the appearance of the blood-vessels in the ears of a
white rabbit. (By permission of Seelig and Joseph.) "To show the contrast between the
constricted vessels still connected with the vaso-constrictor center (left ear) and the control
dilated vessels that have been disconnected from that center (right ear). Drawing made
late in the experiment when the animal was apparently in a state of deep shock. The strong
vaso-constriction in the left ear was replaced by a wide dilatation as soon as the connection
of this ear with the vasomotor center was severed." (From Seelig and Joseph: Jour, of
Laboratory and Clinical Medicine, 1916, i, p. 283.) This illustration shows the continued
marked activity of the vaso-constrictor center in the ears of animals when they are apparently
"in a state of deep shock." The student is urged to be constantly on the watch to see if
he can observe a similar action of the center on the vessels of the kidney, spleen, or intestinal
loop as indicated by the character of the oncometer records in animals which do well in the
early part of an experiment but pass apparently into "a state of deep shock" in the later
stages of the experiment. In this case how would the oncometer records be affected?

Fig. 161. Dissection (dog) showing the position of the left pulmonary vessels and the
sympathetic trunk in the chest above the diaphragm. Ms, mediastinum; Jl/T 1 , mammary
vessels (seen through the mediastinal membranes); T, thymus; / ', vagus trunk; Pa, left
pulmonary artery; Pvs, left pulmonary veins; H, heart covered over by the pericardium.
The connection of the pericardial sac to the diaphragm is torn loose from the diaphragm
at the edge, P; Ph, left phrenic nerve lying on the pericardium; Lit, lower lobe of The
left lung; V, V, branches of the vagus trunks on the esophagus, Oe; Ao, aorta; Sy, sym-
pathetic trunk; D, D, diaphragm; /."', liver; S, edge of stomach.

PRACTICE DISSECTIONS

167

normal position, could you now find these same fibers in
the abdomen! Consult Figs. 158 and 162. Perform a
similar dissection on the right side. Could you find these

Fig. 162. Dissection to show the abdominal viscera (dog). /, intestine; O, omen-
turn; D, duodenum; P, pancreas; Sp, spleen; Li', liver; S, stomach; RK, right kidney;
LK, left kidney; LO, left ovary; RO, right ovary; RU , right ureter; LU, left ureter;
RH . right uterine horn; LH , left uterine horn; U, uterus; R, rectum; B, bladder (pulled
outward and downward).

fibers and stimulate them electrically in a living animal?
On which side are the fibers easier to reach? "What are the
functions of the splanchnic nerves? Consult Fig. 318 to
determine the general distribution of the visceral nerve.

168 EXPERIMENTAL PHARMACOLOGY

EXPERIMENT XVII.

Chloral Hydrate, Urethane, Paraldehyde, Chloretone.
(Frogs: Central Nervous System.)

1. Into the anterior lymph sac (Fig. 66) of a frog in-
ject (see Figs. 125 and 126) one cubic centimeter of four
per cent chloral hydrate solution. Place the frog on
moist cotton in a battery jar and observe its symptoms.
Try its reflexes from time to time by touching it. Turn
it over and see if it can regain its normal position. Are
there any symptoms of stimulation? Some local irritation
may be caused by the drug when first injected. How long
does it take for the animal to become completely narco-
tized? How do the symptoms compare with those pro-
duced by ether, chloroform or nitrous oxide!

2. Into the anterior lymph sac of another frog inject one
cubic centimeter of a ten per cent urethane solution. Care-
fully observe its symptoms, noting the condition of the
reflexes, power of equilibrium, etc., from time to time.
How does this drug compare with chloral or ether?

3. Inject another frog with one-half cubic centimeter of
paraldehyde. Observe its actions carefully and compare
these with those manifested by the other frogs. What
structures or organs are chiefly concerned in the produc-
tion of the symptoms you observe! How would a decere-.
brated frog act under paraldehyde?

4. Inject a fourth frog with chloretone solution. This
solution can be made up as f ollows : Place about half a
gram of chloretone crystals in a beaker and pour a few
drops of absolute alcohol over the drug. The chloretone
should soon dissolve. Now add water until faint traces of
a precipitate (white) begin to appear. Then add just
enouf/li alcohol to redissolve the precipitate. Of this solu-
tion one or two cubic centimeters may be injected into the
frog. (Chloretone is also sometimes dissolved in olive oil
for administration to animals.)

ACTION OF CHLORAL HYDRATE 169

Save all the frogs until next day and note all later symp-
toms. How does the length of duration of the anesthesia
compare with that produced by ether or chloroform? Do
any of the frogs recover? If not, smaller doses may be
tried again.

EXPERIMENT XVIII.
Chloral Hydrate. (Action on the Frog's Heart.)

1. Pith a frog and arrange for recording heart tracings
(see Fig. 63). Obtain one or two normal tracings (show-
ing the effect of vagus stimulation). Start a new round on
the drum and apply four per cent chloral hydrate solu-
tion to the heart with a medicine dropper. Stimulate the
vagus nerve from time to time and note any changes. Con-
tinue the application of the drug until the heart stops.
Time the record and draw three or four horizontal com-
parison lines around the drum between the records. These
lines are made by rotating the drum by hand while a sta-
tionary tambour pointer or signal magnet pointer marks
on the drum. How did the drug affect the tonus of the
heart muscle? Was the inhibitory apparatus affected?
Examine the condition of the auricles and ventricle.

EXPERIMENT XIX.

Chloral Hydrate. (Frog: Retinal Circulation With the

Ophthalmoscope. )

1. Examine carefully an ophthalmoscope (Fig. 163).
Fasten a frog to a board as shown in Fig. 164. Then with
the ophthalmoscope look into the frog's eye from a posi-
tion in front of the animal, but slightly from above and
from the side. Turn the lenses in the instrument until you
find one that permits you to see the red blood vessels in
the fundus of the eye. Examine these carefully. Can you

170

EXPERIMENTAL PHARMACOLOGY

detect any movement inside these vessels? The larger
ones show a motion resembling that of a rapidly moving
belt. Seek out some very fine vessels and watch for move-
ments of the corpuscles. Can you distinguish individual
corpuscles in these finer vessels'? Find a place where a

Fig. 163. Electric ophthalmoscope. The small (replaceable) battery is concealed in the

handle of the instrument.

very small vessel divides. Watch the movements of the
corpuscles as they strike against the walls of the vessel at
the point of division. Can you see this in the human eye?
Now carefully observe the rate and appearance of the
corpuscle flow in some easily observed (very smalt) ves-

RETINAL CIRCULATION CHANGES

171

sels. Keep this observation carefully in mind for later
comparisons.

Under the skin of the back inject with a hypodermic syr-
inge one cubic centimeter of four per cent chloral hydrate
solution. At intervals of five minutes or less again care-
fully observe the rate and appearance of the corpuscle flo\v
in the vessels previously examined. Does the frog become
deeply narcotized? How does chloral affect the heart!

Fig. 164. Position and method used for observing the retinal circulation in a frog.
The ophthalmoscope shown in Fig. 163 is being used, but several other (cheaper) forms
of ophthalmoscopes are on the market and may be equally well employed.

Are the muscular walls of the vessels- directly affected by
chloral hydrate? What conclusions can you draw from
this experiment?

You may repeat this experiment using urethane or
paraldehyde or chloroform to anesthetize the frog if you
have time. Later in your course other drugs, such as nitro-
glycerine, amylnitrite, arecoline, atropine, etc., may also
be used in this experiment.

172 EXPERIMENTAL PHARMACOLOGY

EXPEKIMENT XX.

Chloral Hydrate, Adrenaline. (Turtle's Heart.)

1. Pith a turtle and take a normal heart tracing. Then
drop on the heart four per cent chloral hydrate solution
until the beats become slow. Then drop on adrenaline
solution (1:10,000) and note carefully any change in rate
or amplitude of the heart record. What structures are af-
fected by each drug? What conclusions can you draw
from the experiment?

EXPERIMENT XXI.

Chloral Hydrate and Alkalies.

1. Into a test tube containing two cubic centimeters of
a four per cent chloral hydrate solution pour an equal
volume of potassium hydrate solution. What do you ob-
serve ? Smell the mixture. What do you note ? A reaction
represented by the following equation has taken place :

CC1 3 CHO + KOH = CHC1 3 + HCOOK

What bodies are formed? Are they soluble in water?

EXPERIMENT XXII.

Morphine. (Frog: Central Nervous System.)

1. Into the anterior lymph sac of a frog inject one cubic
centimeter of four per cent morphine acetate solution.
(The sulphate or hydrochlorate of morphine may be used
instead.) Place the animal on moist cotton in a battery
jar and observe its actions. Try the reflexes from time
to time. Are the pupils affected? Is there any change in
the respiratory movements? How does the action of the
drug compare with that of nitrous oxide or chloral? If
the frog becomes completely narcotized do not cast it aside

ACTION OF OPIUM ALKALOIDS

173

hut carefully save it until the next day observing it several
times in the meantime if possible. Do you note any
changes in the reflexes at any time? Does the frog re-
cover? What symptoms are exhibited during the recovery
period? How do you explain this?

EXPERIMENT XXIII.
Thebaine, Codeine. (Frog: Central Nervous System.)

Inject a frog with one cubic centimeter of two per cent
thebaine solution and a second animal with one cubic centi-
meter of two per cent codeine solution. Place the frogs on
moist cotton in a battery jar and watch the symptoms pro-
duced by the drugs. Compare these animals with the one
that got morphine.

EXPERIMENT XXIV.
Morphine. (Chemical Test for Morphine.)

1. Add a few drops of a dilute mixture of ferric chloride
and potassium ferricyanide solutions to a morphine salt so-

N.I

Olfactory nerves
Olfactory lobe

Cerebral hemisphere

N.n

N.vr

Ha Heck-

optic
Hypophysis

Optic lobe
Cerebellum
Medulla oblongata

Spinal cord

Fig. 165. Ventral and dorsal views of a pigeon's brain. (Modified from Wiedersheim.)

174

EXPEKIMENTAL PHAKMACOLOGY

lution. A deep blue color appears. Considerable mor-
phine produces a precipitate of Prussian blue.

Potassium ferricyanide oxidizes morphine to oxy-dimor-
phine :

2 CANO, + 2 KOH + K.Fe 2 (CN) 12 = 2H 2 O + (C 17 H 18 NO 3 ) 2 + 2K 4 Fe (CN).
Morphine Potassium Oxy-dimorphine Potassium

ferricyanide ferrocyanide

Potassium ferrocyanide then forms Prussian blue with

Cerebrum

Optic lobe
Cerebellum

Semicircular

canals
Medulla oblonqata

Spinal cord

Fig. 166. Posterior view of the brain and semicircular canals of a pigeon.

Skin (cut)

Cut edge of skull bone
Cerebrum

Optic lobe
Cerebellum

External ear

Trachea

Semicircular
canals

Medulla

pinal
cord

Fig. 167. Lateral view of the head of a pigeon showing the brain, external auditory

opening and semicircular canals.

GENERAL ACTION OF MORPHINE

175

ferric chloride (Autenrieth and Warren). The instructor
may give you other tests for morphine if he desires to
do so.

EXPERIMENT XXV.

Morphine. (Dog: Respiration, Excretion, Pupils, Central
Nervous System, General Symptoms.)

1. Inject subcutaneously into a dog twenty milligrams
(one cubic centimeter of two per cent solution) per kilo-

0/facfory bulb

Optic nerve

Optic chiasnid
Optic tract

Hypophysis -

Cerebral
peduncle~

Pons-

Olfactory tract
- Sulcus rhinalis

-- Fossa lateralis

idtfv^r

--Pii~i form lobe
-Oculomotor nerve

Jrochlesr nerve
-Tncjemmal nerve

cX:&&r < i *

nerve
Corpus trapezoideum

'$-- Qlosso-pharynqeal verve
' ---Vaqus nerve
--Accessory nerve

Acoustic

P 'd --^^Q^; -' ^^'

^^ii ^N" ! x f:

wM" m
Spinal cord -' W t ''j^ Median fissure

Fig. 168. Base of the brain of a dog. (Modified from Sisson.)

gram of weight of morphine hydrochlorate (or the acetate
or sulphate). Note carefully the size of the pupils and

176 EXPERIMENTAL PHARMACOLOGY

watch for any change in these. Allow the animal to walk
about the room and do not disturb it at first. How is the
respiration affected? Does the animal vomit! If so, can
yon detect morphine in the vomitns ? How is morphine ex-
creted? Is there present an increase in the secretion of
saliva? How do yon account for this? Does the animal
defecate? How is the intelligence of the dog affected?
What later changes do you note in the respiration? Are
there any symptoms of excitement? Take the rectal tem-
perature. When the animal lies down and becomes quiet,
then try its reflexes from time to time by pinching, loud
noises, etc. Eecord the respiration on the drum and watch
for irregularities (Cheyne-Stokes respiration). Are there
any changes in the pupils? Consult several text-books to
find out what action morphine has on the dog's pupil.
Would the administration of ether to a dog that had pre-
viously received a dose of morphine in any way affect the
action of the alkaloid on the pupil? Has the animal's tem-
perature changed? Keep the animal in a quiet place (in
a metabolism cage if possible) until next day and follow
the course of the drug's action as fully as you can. Is
the recovery complete? How long does this require? If
the animal dies what will be the immediate cause of death ?
If you succeed in collecting any urine test this with Bene-
dict's modification of Fehling's solution. Do you get a
positive test? What does this show? If you do not have
this solution use Fehling's or Haines' solution.

EXPEKIMEXT XXVI.
Fehling's Test for Reducing Bodies.

1. Into a test tube pour five cubic centimeters each of
solutions A and B. Bring the mixture to a boil. Is there
any change from a clear deep blue color? If so the solu-
tion is probably decomposed. If no change of color and
no precipitate forms the solution is satisfactory. Add

GENERAL ACTION OF MORPHINE 177

drop by drop to this warm solution five or ten drops of
the urine to be tested. Wait a little while and if no reduc-
tion (yellowish or reddish precipitate) appears, then again
heat the mixture. A red or reddish-yellow precipitate in-
dicates the presence of reducing bodies in the urine. (If
no precipitate forms at once, set the tube aside for a few
minutes and observe it later.) This is usually due to
sugar, but other substances (e. g., glycuronic acid, etc.)
may give a similar reaction. For tests to differentiate be-
tween these bodies the student is referred to text-books
on physiological chemistry.

EXPERIMENT XXVII.

Morphine. (Cat: General Symptoms, Central Nervous

System.)

1. Inject into a cat subcutaneously twenty-five milli-
grams of morphine sulphate (or the hydrochlorate or ace-
tate) per kilogram of body weight. Observe carefully the
symptoms produced by the drug in this animal and com-
pare them with those exhibited by the dog that was in-
jected with morphine. AVhat differences do you note as
regards the pupils, intelligence, reflexes, convulsive tremors,
etc. ?

EXPERIMENT XXVIII.

Morphine, Codeine. (Dog: Respiration, Blood-pressure,
Oxygen Consumption, Urine.)

1. Arrange a dog for recording blood-pressure and res-
piration. Place adrenaline in one injecting burette (femo-
ral vein) and a morphine salt solution (one cubic centi-
meter equals five milligrams) in another burette (femoral
vein). The dog should weigh about ten or twelve kilos. If
you do not have suitable apparatus omit the oxygen deter-

178

EXPERIMENTAL PHARMACOLOGY

Nasal

Maxillary

Premaxillary
Malar

Lachrymal

Temporal

Coronal
Suture

Mastoid

Infer parietal

Fig. 169. The upper surface of the skull of a cat. (Partially adapted from Jayne. )

THE CAT S SKULL

179

m

O

TO

p_

l-h

O
i-h

S-

r-h

n

p
<;

3
ft

/

s

Q>

X

^

O,

^*^_,^

^
re

3
OP

Vomer.

a

X

0~
i
f

3-

5*

y>

^

^

^M

O>

J

-t

<F

-

-s
o~

-*

^

o-

5 '

L^

. 5i-
CO

I

t>

rnb-i

-* ; A*

-o'

1 i

2--o

.^|

o

D-"

180

EXPERIMENTAL PHARMACOLOGY

urination and proceed with the remaining observations.
To determine marked changes in the rate of oxygen con-
sumption by the animal an apparatus similar to that shown
in Fig. 172 is required. (See also Fig. 175.) This con-
sists essentially of the anesthetic apparatus shown in Fig.
116 but with the addition of a four or six inch thin alumi-
num (or pasteboard) disc which rests (stuck on with nraci-

Olfactory lobe

Crucial fissure

Lateral sulcus

Suprasylvian
sulcus

Great

longitudinal
fissure

Lateral lobe of

cerebellum

Posterior pyramids
Cray matter of cord

Oyrus Marginal is
Oyrus Suprasylvius
Oyrus Ectosylvius

Vermis of cerebellum

Ned u I Id oblongata
1st. cervical nerve
Spinal cord
White matter of cord

Fig. 171. Dorsal surface of the brain of a cat. (Partially adapted from Daviscn.)

lage) on top of the bath cap covering the large pan in the
bottom of which is placed strong (not saturated) sodium
hydrate solution [Ca(OH) 2 may also be added if desired]
to the depth of about three-fourths or one inch. Oxygen is
run into the breathing pan from the tank as needed. In
the center of the aluminum disc are two small holes in
which is tied a twine string about four feet long. One, two
or three bull-dog forceps must usually be laid on the top of
the disc to cause it to move down readily as the dog in-
spires. As the dog expires the disc moves upward. These

RATE OF OXV(JKX CONSUMPTION

181

Counter balancing
qht

Vooc.c.

Graduated

cylinder

Fig. 172. Arrangement of apparatus for recording and measuring the rate of oxy-
gen consumption. (See also Fig. 175.) The side tube of the trachea! cannula opens
into the interior of the large square pan. The trough (Fig. 173) is filled with water
and the breathing pan dips up and down in the water. A layer (3/4 inch deep) of
strong sodium or potassium hydrate solution is placed in the bottom of the inner pan
to absorb the CO 2 exhaled by the animal. If the clip on the tube leading from the
graduated cylinder to the pan be closed while the oxygen tank is opened a little, the
water in the cylinder will be forced up into the pressure bottle. When the cylinder is
thus filled with oxygen the tank valve is closed. The oxygen remains stationary in the
cylinder but can be immediately run into the pan by opening the clip on the com-
municating rubber tube, as the water in the pressure bottle will quickly run down and
displace the oxygen which is thus forced out into the pan. This causes the writing
lever on the drum to make a sharp rapid descent. As the animal uses up the oxygen
and the breathing pan slowly descends the writing point on the drum slowly goes up.
(See Fig. 175.)

182

EXPERIMENTAL PHARMACOLOGY

fairly rapid movements up and down correspond to the
regular respiratory movements of the animal. But in ad-
dition to these rapid movements a larger and more pro-

Breathinq pan

Inner pan
Trouqh (wafer)
Outer pan

Respiratory
openinq
NaOH solution

Hinge rod
Oxyqen inlet
Ether inlet

Fig. 173. Inner construction of the pans shown in Fig. 172. These pans can be
made of sheet brass or tinned iron. Pans which can be used for the purpose can often
be purchased at a hardware store (or a ten cent store). (See Journal of Laboratory and
Clinical Medicine, 1916, ii, p. 145; also ibid, 1916, ii, p. 94. )

Removable
hinge rod

Counrerbalancinq
weiqhf-

Stopper

Ji Inches

13 xiz

r. T. rtillrck

Fig. 174. Lateral view of a cross-section of the apparatus shown in Fig. 172. The
breathing pan is best made of very thin sheet brass (which is easily soldered and is not
affected by alkalies as is aluminum). The pan should be carefully counterpoised with
an adjustable weight. The dimensions are indicated in inches on the scale.

longed movement of the disc occurs. This corresponds to
the injection of oxygen from the tank into the pan when
the disc will be lifted up a considerable distance (perhaps

RATE OF OXYGEN CONSUMPTION

183

one inch), and then to the gradual consumption of this
oxygen by the dog during which interval the disc will be
falling (one inch). During all this time the exhaled car-
bon dioxide is being absorbed by the alkali solution. The
twine string attached to the disc passes over two pulleys
(one inch brass wheels these should be of the best quality
and can be bought at any good hardware store for about
twenty or thirty cents apiece). The opposite end of the

Fig. 175. A simpler arrangement for recording the rate and amount of oxygen
consumption by an animal. (See also Fig. 172.) There is more chance for "lost mo-
tion" by use of the flexible bath cap over the pan than with the apparatus shown in
Fig. 172. (See Journal of Laboratory and Clinical Medicine, 1916, ii, p. 94.)

string is clamped on to the long arm of a frog heart lever
by means of a bull-dog clamp. Two clamps may be neede'd
to draw the lever down readily. These clamps serve not
only to hold the string to the lever but act as balancing
weights as well. The heart lever writes at the top of
the drum, below this is the blood-pressure (mercury ma-
nometer), next the respiration (tambour connected to the

184 EXPERIMENTAL PHARMACOLOGY

stethograph drum), and at the bottom is the base line and
time marker. The drum should have an approximately
constant slow speed.

The arrangement of the apparatus and records is shown
in Fig. 175. The anesthesia should be fairly light and
maintained solely with ether (since morphine is injected
later). If the apparatus is in good condition the anesthe-
sia will be approximately constant. Observe the character
of the tracing on the drum, also Fig. 180. The thin narrow
curved lines in the oxygen consumption record are made
while the drum is standing still. This narrow line repre-
sents the downward movement of the lever as the pan is
filled with oxygen. The extent of this down stroke is op-
tional but should be regulated by the tension of the oxygen
on the bath cap. The cap should not lie filled so full as
to stretch it, as this would cause too great a mechanical
obstruction to the breathing of the animal'. This must be
carefully avoided. When the pan is filled sufficiently with
oxygen the writing lever will have descended to a certain
level on the drum. This level marks what may be termed
the lower base line for the oxygen record. In filling the
pan with oxygen at all later times see to it that the lever
again descends to this same level as nearly as you can de-
termine. This is done by watching the lever go down as
oxygen is run in very cautiously. Conversely the highest
point in the oxygen record may be called the upper base
line for this record. If while the drum is stopped the lever
be run down to the lower base line by adding oxygen to the
pan, then just as the lever reaches the base line the injec-
tion of oxygen is stopped and the drum is started. (It is
desirable that the drum start quickly and soon reach the
maximum for that rate of speed.) As the drum runs the
lever moves up and down a short distance rapidly at each
inspiration and expiration. We are not much concerned
now with these short, rapid movements as they correspond
fairly closely with the respiration tracing from the stetho-

THE GENERATION OF OXYGEN

i sr>

Mercury bulb
or funnel

To anesthetic

device or to

reservoir

lOTHl.mVUW

'.IIIIIUUMI.

Wash
borHc

Fig. 176. A cheap form of apparatus used lor making pure oxygen. Sodium per-
oxide^ is placed in the left hand bottle and water is allowed to drop slowly down on to
the NaoOo from the mercury bulb above. Oxygen is liberated and at once bubbles over
through the water in the wash bottle. In one experiment 74 grams of sodium peroxide
generated sufficient oxygen to run a IS kilo dog for one hour. At the end of this period
the left hand bottle was exchanged for a second (quart milk bottle) containing a sec-
ond 74 grams of sodium peroxide and this again liberated sufficient oxygen to run the
animal another hour. In this experiment the closed anesthesia apparatus shown in Fig.
116 (see also Fig. 175) was used. It is advisable to use some kind of reservoir to catch
the oxygen generated as the rate of liberation cannot be controlled accurately by the
addition of the water.

186

EXPERIMENTAL PHARMACOLOGY

graph drum. These movements do, however, with many
drugs, record very profound and striking changes in the
bronchioles. (Can you detect any evidence of this when
morphine is injected into the femoral vein?) But the im-
portant point in the oxygen record is the gradual rise of
the lever as the oxygen in the pan is consumed by the dog.
The rate of this rise determines the rate of oxygen con-
sumption. Watch carefully and when the lever reaches a
satisfactory altitude (this will vary with each experiment
and the student with a little practice can estimate about
when to stop), which will generally be about two inches
if a large drum is used (lower and less magnified if a
small drum is used), then suddenly stop the drum and at

Rubber bath cap

9

das inlet

9*W Cake pan
Flanqeonpan
Added flanqe

Gas outlet 1

Fig. 177. A simple gas reservoir made from a very shallow, wide, round cake pan
with two spouts soldered into the walls. A large bath cap is stretched over the pan
and serves to form an adjustable gas reservoir suitable for use with the apparatus
shown in Fig. 176. A small spirometer ( 1 or 2 gallons) may also be used as a reservoir.
The spirometer should be delicately counterpoised as the oxygen is not delivered from
the wash bottle under a high pressure. A large, thin walled rubber bag may also be
used.

once run a fresh supply of oxygen into the pan. The lever
comes down and when the base line is reached stop the
oxygen inflow and immediately start the drum. (If the
drum is exceedingly slow the oxygen can be run in while
the drum is turning. This is very convenient.) When the
lever again reaches its former high point stop the drum
and at once reinject oxygen. This gives a saw-tooth like
record. And the distance between each two consecutive
teeth or descending narrow lines in the record gives a
measure of the relative amount of oxygen consumed dur-
ing that period of time. Tf a drug which slows the con-

OXYGEN DETERMINATION

1ST

sumption of oxygen is given, then the distance between
the consecutive descending lines will be increased; while
a drug which increases the relative consumption of oxy-

To suction apparatus

-Large glass tube or Liebig condenser
with graduated scale (c.c.)

Removable pinchcocks
' Inspiratory\

4-1, ;. *

To trachea
of animal

Glass tube

Large
glass
jar or
dish

/Inspiratory
valve

Fig. 178. Dreser's arrangement of apparatus for recording the volume of air ex-
pired by an animal in a given length of time. The large glass tube (or Liebig con-
denser jacket; is filled with water which is supported up in the tube by the pressure
of the atmosphere. The by-pass is closed and the clip on the tube leading from the
milk bottle inspiratory valve is removed. When the animal inspires, air enters the in-
spiratory tube, bubbles through the water in the bottom of the bottle and thence passes
to the lungs. At expiration the air passes through the straight course of the tubes to
the large glass jar or dish and thence is liberated in the lower end of the large glass
tube. The exhaled air then quickly displaces the water and rises to the upper part of
the large glass tube where it can be measured on the scale.

188

EXPERIMENTAL PHARMACOLOGY

gen will cause a decrease in the distance between consecu-
tive descending lines.

If the instructor desires it is an easy matter to place a
gas measuring device in the path of the oxygen inflow tube

' II

To recording
tambour

Mercury bulb

Hemostet

Bladder cannula

into beaker
or to recorder

Urachus
Loose liqature

Fig. 179. Technic for inserting a bladder cannula or for connecting a mercury bulb
to record bladder contractions. (For discussion see text.)

and measure the amount of oxygen run in at each filling
of the pan (see Fig. 172). This is instructive and is a
valuable procedure in the beginning, but with a little prac-
tice the operator will be able to attain sufficient accuracy

RATE OF OXYGEN CONSUMPTION 189

by simply watching the lever as it writes on the drum. A
monkey wrench is better than the regular wheel wrench to
control the valve on the oxygen tank where careful regu-
lation is needed. It is very desirable to have the tank
fastened doAvn with a clamp to the table (see Figs. 112 and
113).

To obtain urine for tests the abdomen is opened over the
bladder which is caught in a hemostat at the urachus (Fig.
179). The bladder is then raised a little and a second
hemostat is clamped on the opposite side of the urachus
in such a manner that an opening can be cut with a scalpel
or scissors just between the tips of the hemostats. Be-
fore this opening is made place a twine string around the
upper part of the bladder (just below the points of the
hemostats) and tie it loosely. Open the bladder (do not
allow any urine to escape or blood to run down into the
bladder if it can be avoided) and quickly insert the blad-
der cannula. Tie the ligature and replace the bladder
within the abdomen which is closed by hemostats. Catch
the urine in a beaker and test some early to see if it con-
tains glucose.

When all apparatus is adjusted start the drum and
take several records of the oxygen consumption in order
to become familiar with the method and to get some nor-
mal records. Your success will depend largely on your
ability to determine exactly when to stop and start the
drum and to judge when the lever has gone high enough.
This is the most diffcult part of the experiment and should
alivays be done by that member of the group who is best
able to carry out this work.

Your "normal" oxygen records should be almost exactly
alike both in form and in the distance they occupy on the
drum.

Inject one cubic centimeter of morphine. Watch the
oxygen records closely and make your changes promptly.
When the records all return to normal inject three or four

190 EXPERIMENTAL PHARMACOLOGY

cubic centimeters and record the results. Do you get what
you expected? Does the anesthesia remain regular? How
are the respiratory movements affected? Does the rate
of oxygen consumption correspond with the rapidity or
slowness of the respiratory movements or with the height
of the blood-pressure? Would you have expected these re-
sults? Now take one or two normal oxygen records and
then when the oxygen lever is getting pretty well up to
the top of its course inject one-half cubic centimeter of ad-
renaline. Watch carefully to reset your oxygen record at
the exact moment. Be sure before the adrenaline is in-
jected that the rise in the manometer writing point will
not interfere (catch] ivith your oxygen lever. Watch your
oxygen record closely and make the changes promptly.
Take at least two or three minutes to record this after the
adrenaline is injected. Do you observe any peculiar
changes in your records? If not, wait a Avhile and repeat
the adrenaline injection.

How does morphine affect the heart? Can you detect
any change in the rate? Give more morphine from time
to time (two cubic centimeters per dose), and see if you
can bring on a Cheyne-Stokes form of respiration. Does
the anesthesia become any deeper? Examine the pupils
carefully. Are they in the same condition as were those
of the dog in Experiment XXV? Does this agree with the
text-book descriptions?

Inject as much morphine as you think (from the ap-
pearance of the respiration, blood-pressure, etc.) the ani-
mal can safely stand. You may not get a Cheyne-Stokes
form of respiration, but many small repeated doses are
very liable to bring it on. Variable but constantly repeated
irregularities of the respiration often appear.

Allow the animal to recover a little if it will and then
inject codeine (two cubic centimeters 1 c.c. = = 5 nig.). Get
a record of this and then increase the dose given. After
a few injections (and within half an hour), marked symp-

ACTION OF MORPHINE ON OXYGEN CONSUMPTION

191

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sro
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192

EXPERIMENTAL PHARMACOLOGY

toms should appear. Test the urine for glucose. Is there
any reduction? How do you account for this? Kill the
animal with codeine.

2. If time permits carry out the following dissections.

Fig. 181. Record showing the action of adrenaline on the rate of oxygen consump-
tion, uterine contractions, blood-pressure and respiration. There is a slight slowing
down of the rate of consumption of oxygen which is mainly concordant with the period
occupied by the fall in blocd-pressure after the large initial rise. (See Journal of Lab-
oratory and Clinical Medicine, 191t>, ii. 145.)

Isolate both the internal and the external jugular veins
on each side. (See Figs. 133 and 183.) Note carefully in
just what portion of the neck tissues these vessels are

PRACTICE DISSECT IOX

I!).'!

located. Could you pass a large needle in at the median
incision in the neck and then push it out through the tis-
sues in the side of the neck in such a manner as to in-
clude both the jugulars on one side in a ligature threaded
through the eye of the needle? If you should thus tit 1 a
ligature loosely around a portion of the tissues in the
side of the neck (including both veins), and then should
lift up with a moderate degree of pressure on the ligature,
what effect would this have on the back How of blood
through the veins to the heart? How much pressure does
it take to shut off the flow through a vein? Carry your

Cervical nerves

Diaphragm

Vaqo

symp.

trunk

Cervical
vertebrae

Fig. 182. Schematic representation of the origin, course and distribution of the right
phrenic nerve in a dog. (The origin varies in different animals.)

dissection well down on to the longus colli muscle in the
right side of the neck (Fig. 184) and find the right verte-
bral artery. Pass a large aneurism needle under the ves-
sel, lift it up and slip a ligature around it. What is the
distribution of this vessel? Could you inject a solution
from a hypodermic syringe into this vessel toward the
head? How long a space would you have to operate on
the vessel? If you do not find it readily, pick up the right
subclavian artery and find the vertebral from this. Could
you make the dissection icitlwiit getting into the chest cav-

194 EXPERIMENTAL PHARMACOLOGY

ity? Pick up the right phrenic nerve. AVhat is the origin
of this nerve? If you do not find it readily open the chest
and locate it on the pericardium at the side of the heart.
Trace it from here back up into the neck. Could you cut
both phrenics in the neck icitlwut opening the chest? This
is sometimes done to stop movements of the diaphragm
when these interfere Avith certain records that are being-
made.

EXPERIMENT XXIX.

Morphine, Codeine, Pantopon, Heroine, Peronine, Dionine,
Narcotine or Thebaine. (Spinal Dog: Bronchioles.)

1. This is a new field of experimentation for most med-
ical schools. Many drugs act vigorously on the bronchioles
and it is unfortunate for medical students not to have
some opportunity to perform experiments to bring out
these results, for the action of these drugs is often much
more striking on the bronchioles (and perhaps frequently
as important) than are the corresponding actions on the
heart or other organs. Several methods will therefore be
given in different experiments in order to give every lab-
oratory a chance to carry out such experiments. The best
(but perhaps the most complicated) method will be given
in Experiment LXX. For peripherally acting drugs it is
advisable to use spinal dogs. (Cats may also be used for
this work but dogs are better.)

Before starting the experiment be sure to arrange for
a reliable source of artificial respiration. This should be
from an artificial respiration machine, but a hand-bellows
fixed to open only a given distance (to regulate the stroke)
may answer.

Etherize a dog and arrange it for a blood-pressure trac-
ing. Place injecting burettes in connection with the fem-
oral veins. One burette contains adrenaline (1:10,000),
the other an opium alkaloid. Any one of those at the head

Exf. jugular vein...
Carotid artery -
Inf. juqular v.~

Transverse scapular

cervical ascending arteries

Subclavian vein

Fig. 183. Dissection of the lower part of the neck and upper part of the chest on the
right side in a dog. (Modified from Schmiedebcrg. )

Ext. jugular vein ^^
Carotid artery
Int. jugular vein-^. N
Vaqo sympathetic x
nerve x
Vertebral artery % vein^

Deep cervical artery .\

Transverse scapular

ascending cervical arteries^

Rt. subclavian artery* Rt. mammary artery

Fig. 184. Dissection of the lower part of the neck and upper part of the chest and
of the axillary region in a dog. (Modified from Schmiedeberg. )

BRONCHIAL ACTION OF OPIUM ALKALOIDS 195

of this section may be used, but either heroine, codeine or
dionine will probably give the best results. Be sure the
drug is fresh and of first-class quality. Codeine possesses
some advantages in this respect. The strength of the solu-
tion chosen should lie five milligrams to the cubic centi-
meter.

With great care to avoid opening tlie chest at the apex
dissect down on the right side of the neck (see Experiment
XXVIII, 2; also Figs. 183 and 184), and pick up the right
vertebral artery. Place a ligature around the vessel and
tie the ligature once loosely. The ends of this ligature are
brought together and clamped with a hull -dog so it can
be found readily. Now with a large (five or six inch)

Fig. 185. Large needles for sewing with heavy twine.

needle (Fig. 185) pass a ligature of heavy twine through
the tissues in the side of the neck in such a manner that
both jugular veins will be included. The carotid artery
and vagus nerve must not be included. The ligature passes
out through the skin at the side of the neck. The two ends
of the ligature are brought together and tied once loosely
and clamped with a hemostat. Another ligature is simi-
larly placed on the opposite side so that in this way the
chief venous return flow from the head can be quickly
clamped off. Now fill a small syringe (two cubic centi-
meters) of good quality with chloroform. The point of the
syringe should be as small and as short as possible. A
cheap syringe is very liable to leak chloroform. Get all
apparatus properly adjusted and then lift up the vertebral
artery on an aneurism needle and insert the syringe point

196

EXPERIMENTAL PHARMACOLOGY

into the lumen of the artery pointing toward the animal's
head. This should be done with great care and no chloro-
form should be emptied out in the wall of the vessel. The
assistant now takes hold of the ligatures (hemostats) that

Fig. 186. Brass tube (//,. inches long and J4 inch in diameter) with (separable)
spear point to be passed through the chest for recording lung volume changes. The
holes cover a space about 2 I / 2 inches long.

control the jugular veins and gets ready to close off (by
pressure) these vessels. It is advisable for a second as-
sistant to put a bull-dog clamp on the left carotid at this
moment. The operator then injects the chloroform (one

To recording
tambour

Requlatmq by pass

I
Perforated brass tube

- 6t /n fere 05 fa/ space

Fig. 187. Arrangement of animal for recording lung volume changes. (For descrip-
tion see text.)

or two cubic centimeters) into the vertebral artery. This
chloroform quickly reaches the brain and destroys all parts
with which it comes in contact. The blood-pressure falls

CHLOROFORM INJECTION INTO VERTEBRAL ARTERY

197

rapidly and artificial respiration must be started at once.
Close off the jugulars immediately and tie the ligatures
firmly. Be sure the lungs are well inflated but do not burst
them. Remove the ether quickly as no further anesthetic
is needed. If your first injection does not succeed well,
make a second one into the left carotid artery. Luckhardt

-Cenfaqrade
thermometer

Fig. 188. Arrangement of apparatus for keeping the systematic blood-pressure at a
constant level during the action of drugs which produce marked changes in the caliber
of the arterioles. The cannulas in the femoral arteries are connected with a siphon tube
which dips in a beaker containing warmed salt solution (or whipped or hirudinized
blood). Hirudin is injected intravenously to prevent clotting of the blood. The alti-
tude of the beaker above the animal regulates the pressure which can be maintained
in the blood vessels. This is read off from the mercury manometer. If the vessels
contract blood is forced over into the beaker but the arterial pressure does not rise.
When the vessels (arterioles) dilate the blood siphons back into the femoral arteries.

has succeeded well by making- injections into the carotid
artery alone. (Some workers have obtained good results
by injecting a three per cent suspension of starch gran-
ules into the carotid artery.) This is easier than inject-
ing the vertebral on account of the dissection, but the me-
dulla may not be well reached through the carotid. In a

198

EXPERIMENTAL PHARMACOLOGY

Fig. 189. This lung volume and blood-pressure record was taken from a dog by the
use of the blood-pressure regulating device shown in Fig. 188. The lung record was
taken by means of (positive) artificial respiration (using the tube shown in Fig. 186 and
the method illustrated in Fig. 187). The purpose of the. tracing was to show that con-
traction or dilatation of the bronchioles is practically entirely independent of the changes
in systemic blood-pressure. The slight variations in the course of the carotid pressure
tracing were due to the great suddenness of the extensive changes in caliber of the
arterioles produced by the action of the drugs, i. e., the contraction of the arterioles
occurred slightly quicker than the blood could siphon over through the small pointed
cannulas into the beaker. But if no equalizing device had been used the carotid pressure
would have risen above the top of the lung tracing.

BRONCHIAL ACTION OF OPIUM ALKALOIDS

199

spinal dog the blood-pressure will be about one inch above
the base line on the drum. Do not be alarmed so long as
it remains this high and is not falling. If any of the chloro-
form gets back to the heart, the dog may die quickly. If
the animal is about to die inject one-half or one cubic

Fig. 190. Blood-pressure and bronchiole tracings showing the action of morphine
in a dog. These tracings were made by the method described in Experiment LXX, page
287.

centimeter of adrenaline. When the blood-pressure is reg-
ular, then pass a brass tube (Fig. 186) directly through
the chest walls at the level of the ventral border of the
sixth intercostal space (see Fig. 187). To do this make

200

EXPERIMENTAL PHARMACOLOGY

an incision through the skin on each side in the proper
place. Then push the spear point of the tube right through
the muscular walls from side to side. Do this as the lungs
are deflated. Be sure the tube passes inside the chest cav-
ity and does not slip along under the parietal pleura just

HH.'fi I
I 11

/-I 0,000

Fig. 191. Blood-pressure and bronchiole tracings showing the action of pantopon.
(Pantopon, or pantopium hydrochloricum, is the hydrochloric acid extract of the total
alkaloids of opium very soluble in water, sold by IIoffmann-LaRoche Chemical Works,
New York.)

BRONCHIAL ACTIOX OF OPIUM ALKALOIDS

201

below the sternum. Eemove the spear point from the tube
and place on this end a piece of rubber tubing carrying a
screw clamp. This is to regulate the amount of air going
into the tambour which is attached to the other end of
the tube. Clamp the brass tube tightly in the chest walls

Fig. 192. Blood-pressure and bronchiole tracings showing the action of peronine.
"Epinine" failed to cause dilatation of the bronchioles and the animal died of asphyxia.
It could easily have been saved by forcibly dilating the lungs mechanically to check the
asphyxia.

202

EXPERIMENTAL PHARMACOLOGY

by hemostats on each side. The tambour should have a
large boAvl (three inches, see Fig. 14). Bring the writing-
point of the tambour on to the drum above the blood-pres-
sure and adjust the tambour to give a tracing about two
or three inches high. The force of the respiration may
have to be changed to give this. The rate of inflations

Fig. 193. Blood-pressure and bronchiole tracings showing the action of dionine.
Adrenaline caused a prompt dilatation. The method used is described in Experiment
LXX, p. 287.

should be about twenty or twenty-five times per minute.
Start off the drum (slow speed) and take one or two inches
of normal record. Then inject five cubic centimeters of
the opium alkaloid solution. The blood-pressure falls at
once but the heart should not stop. What does the lung

BRONCHIAL ACTION" OF OPIUM ALKALOIDS

I'D:;

volume show? Did you get what you should get? "\Vhen
the action of the drug has become very marked inject one
cubic centimeter of adrenaline. How does this affect the
blood-pressure and lung volume? Does the one depend

Fig. 194. Blood-pressure and bronchiole tracings showing the action of narcotine.

on the other! (They do not each is mainly independent
of the other; see Figs. 188 and 189).

When the records again become normal then inject six
cubic centimeters more of the opium alkaloid. Do you get
a second lung volume tracing? Inject some adrenaline to

204

EXPERIMENTAL PHARMACOLOGY

revive the animal. Now stimulate each vagus nerve in
the neck to see the effect on the heart and lungs. What
is the innervation of the heart and bronchioles ? If the
animal is still in a suitable condition, inject six cubic centi-
meters, of a different opium alkaloid. Do you get lung
records! Give some adrenaline to help revive the animal.
The abdomen may now be opened by a three inch median

Fig. 195. Respiratory and blood-pressure tracings from a dog showing the progres-
sive actions of narcophine (Straub), narcotine and morphine. The peculiar irregularity
of the respiration is developed early and leads to the Cheyne-Stokes type of respiration.
What is the cause of Cheyne-Stokes respiration? Does the peripheral action of these
drugs (note the size of the doses) have anything to do with the respiratory disturbances?
The vagi were intact.

longitudinal incision down near the pubic symphasis and
the bladder lifted up as described in Experiment XXVIII,
page 189. The animal will probably be dead by this time.
Could you thus pick up the bladder and place a cannula
in it in this manner in a spinal dog without letting the ani-

ACTION OF CANNABIS INDK'A

205

mal die? How might you do such an experiment and avoid
opening the abdomen after the brain of the animal was
destroyed? "What are the main differences that you note
between the reactions and vitality of a spinal dog as com-
pared with a normal animal?

Fig. 196. Method of administering capsules, pills or tablets to dogs. The tongue
is pulled forward and the prepared dose is dropped far back in the mouth. The jaws are
held closed and the animal is gently slapped under the throat, or a little water may be
given. The method illustrated is frequently used in testing (standardizing) cannabis
indica preparations. The U.S. P. doses are: fluidextract 0.03 cubic centimeter, extract
0.004 gram and tincture 0.3 cubic centimeter per kilogram of body weight, for small or
medium-sized, smooth-haired (preferably fox terrier) dogs. Doses not larger than these
should produce incoordinatioii (best observed when the animal is standing still) and
slight ataxy in walking. The animal should be kept in a quiet room and the symp-
toms may not become marked (or even perceptible) for one or two hours. In three or
four hours the symptoms entirely disappear. The administration of 3/4 grain of "can-
nabinole" in oil (in globules) to a dog weighing about 4 to 6 kilos, is recommended for
demonstrating marked symptoms. (For the method of standardization of cannabis
indica, see U.S. P., ix, page 60S.)

One may destroy the cerebrum only in an animal and
thus leave the medullary centers intact. This is easiest
done in a cat. Normal respiration may go on (no further
anesthetic is needed) and the blood-pressure remains high.

206

EXPERIMENTAL, PHARMACOLOGY

EXPERIMENT XXX.

Heroine or Codeine. (Spinal Dog: Blood-pressure, Lung
Volume and Bladder Contractions.)

1. Examine carefully the apparatus shown in Figs. 197
and 198. Arrange a dog (ten or twelve kilos) for record-

Fig. 197. Mercury bull).

ing blood-pressure. The injecting burettes contain heroine
(one cubic centimeter equals five milligrams) and adrena-
line (1:10,000). Arrange for artificial respiration.

Open the abdomen and pick up the bladder. Insert into
it at the urachus a glass tube connected with a mercury

PRELIMIjSTARY OPERATIONS

207

bulb. (See Figs. 198 and 199 for teelmic and apparatus;
also see Experiment XXVIII, page 189.) Use a large
bowled tambour to record the bladder contractions. If the
bladder is full of urine do not allow more of this to escape
than can be avoided. Arrange the mercury bulb as shown
in Fig. 199 and fill the bulb about two-thirds full of warm
salt solution. Insert the cork which carries a glass tube
to connect with the tambour. It is best not to connect the
tambour tube until the lung shield is inserted and the dog

Air

Mercury bulb
zso c.c.

Salt solution

Larqe bowled

recording tambour

Class or metal tube
orooved where tied
into bladder wall.

Abdominal wall

Fig. 198. Arrangement of apparatus for recording bladder contractions. A catheter
passed through the urethra may also be used sometimes to connect to the mercury bulb.

is pithed, as the bladder tambour and tube would be in
the way of the operation. Place a hemostat on the penis
or vulva of the animal to prevent urination.

By a median longitudinal incision open the thorax (start
artificial respiration at once) and expose the right lung
and the heart (do not open the pericardium). The anterior
mediastinum should, if possible, be gently turned over to
the left. Pick up both phrenic nerrc.s and cut iliem.

208

EXPERIMENTAL PHARMACOLOGY

The lung shield (Fig. 200) should be dipped in warm water
and inserted in the chest in such a manner that the large
notch at the lower border of the shield will just pass over
the pedicle and vessels of the right lung. The flanged
portion w T hich turns outward at the right hand end of the
shield rests on the anterior surface of the diaphragm.
There is a groove in the shield between the large notch and
the out-turned flange. This groove is for the passage (ine-

Fig. 199. The forefinger is placed over the inguinal region just at the lower edge
of the abdomen. The beating of the femoral artery should be felt just beneath. An in-
cision should be made just over the area. Note the little fold of skin picked up by the
forceps while the scissors are vised to cut away the skin and fascia. Do not use a
scalpel here. The arrangement of the mercury bulb for recording bladder contractions
is also shown.

sially) of the inferior vena cava. This must not be closed
off or the dog will die. Now cut a small hole in the skin
of the right side about the position of the anterior border
of the sixth intercostal space. Pass an aneurism needle
through the muscular wall (through the skin incision) and
into the chest. Be sure tlie parietal pleura does not peel

ADJUSTMENT OF LUXG SHIELD

I'D!)

off and keep the aneurism needle from entering the chest
cavity proper. Beside this aneurism needle insert another
in the same opening and pull the sides of the opening thus
made far enough apart to insert the bent end of the glass
tube shown in Fig. 201. Be sure the pleura does not close
the inner end of the tube. This is the most common source
of failure in this experiment. The edge of the lung may
also move up when inflated and close the tube. Watch this.
With hemostats clamp the glass tube (catching the
strings) air-tight in the chest wall. Now close the chest

Fig. 200. Lung shield made of thin sheet brass with a wire rim soldered around
the edge to add strength. A little more than one-half natural size. The large notch
passes down over the pedicle of the right lung. To the right of the large notch is seen
a grooved channel for the passage (mesially) of the inferior vena cava. (For method
of use see text.)

and fasten it air-tight either with hemostats or by sewing.
Connect the glass tube to a large bowled recording tam-
bour. This records the lung volume changes. The record
should be about two to three inches high. The adjustable
by-pass may be opened to allow excess air (which the tam-
bour can't hold) to escape. (Air also will then enter the
by-pass again when the lungs collapse. This exchange is
approximately constant, however, with regular artificial
respiration and will not interfere with the validity of the

210

EXPERIMENTAL PHARMACOLOGY

record.) The animal should be firmly tied down to the
operating board so the chest cannot move too much.

Now pass ligatures through the sides of the neck as dp-
scribed in Experiment XXIX, page 195 (see also Experi-
ment XXVIII, 2, page 192 and Figs. 183 and 184). Isolate
the left carotid artery and arrange to inject chloroform
(one or two cubic centimeters) into it. Proceed as in Ex-
periment XXIX to destroy the animal's brain, but try to

Glass tube

;7b recording tambour

Hemostat clamping string
on corK to cftesr,

Adjustable c/a/np
(by-pass)'

Fig. 201. Arrangement of apparatus for recording the volume changes of the right
lung by use of the lung shield. The glass tube shown in the upper part of the illustra-
tion has its bent end passed into the chest cavity.

do this by injecting the chloroform into the left carotid
artery alone. If you succeed well in this you can avoid
dissecting out the right vertebral artery. The blood-pres-
sure should come down at least to a height of one or one
and one-half inches above the base line as seen on the drum.
If the pressure does not fall, or even goes up higher, the
injection has not succeeded. A very high pressure thus

ACTION OF OPIUM ALKALOIDS 211

produced may last for some time and is very liable to cause
the heart to stop (possibly from the extra strain). The re-
spiratory movements of the dog should stop entirely. If
they do not, wait a little while and make a second chloro-
form injection. Sometimes the diaphragm will contract
at every beat of the heart. This is due to an action cur-
rent generated by the heart where the phrenics pass over
it. These nerves should therefore be cut between the heart
and the diaphragm (while the chest is open).

The animal should now lie quietly and the blood-pressure
should be about one inch or a little less above the base line
on the drum. Just above the blood-pressure should be the
lung volume record (about two or three inches in height),
and above this about one-fourth inch should lie placed the
tambour record for the bladder which is now connected up
to the mercury bulb. Take about one inch of normal trac-
ing. If everything is satisfactory then inject five cubic
centimeters of heroine (or codeine) solution. Is there any
change in the bladder? If not it may have been completely
empty and contracted before the drug Avas injected. Do
you get any lung volume change"? How do you account
for this? What mechanical factors are involved? How
does positive artificial respiration differ from natural res-
piration? As soon as you get a well marked action from
the drug injected, then run into the vein one cubic centi-
meter of adrenaline. How does this affect your record?
How do you account for this? Of what clinical use might
this be? What effect does this have on the bladder? How
do you explain this?

Wait until the records return to normal and then inject
eight cubic centimeters of the second alkaloid (codeine
or heroine, or vice versa, depending on which drug was in-
jected the first time). How does this drug affect the blad-
der and lungs? The dose is larger than the first one given.
How do these doses compare with those given to dogs to
narcotize them before operations? Has the first injection

212

EXPERIMENTAL PHARMACOLOGY

Fig. 202. Bladder contraction, lung volume change (bronchioles) and blood-pressure
from a dog, showing the action of heroine and adrenaline. Both brain and cord were
destroyed. The tracing was made by the method described in Experiment LXX.

ACTIOX OF OPIUM ALKALOIDS

213

1111

Fig. 203. Tracing showing the action of codeine and "epinine" on the bladder, bronchioles

and blood-pressure in a pithed dog.

214

EXPERIMENTAL PHARMACOLOGY

i Hi !' ' ! Hi i

ill

A\vU\\H\n\nH\v

Fig. 204. Tracing showing the action of muscarine (and "epinine") in a pithed dog alter
the animal had become irresponsive to codeine injections.

ACTION OF OPIUM ALKALOIDS

215

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216

EXPERIMENTAL PHARMACOLOGY

caused any permanent change in the lungs or bladder that
yon can detect by the results of your second injection?
Give more adrenaline to revive the animal. Do you see
the reflected effects of the filling and emptying of the heart

c |II-M -

Flexible rubber catheter

Class catheter

Metal catheter

Fig. 206. Three kinds of catheters.

in your lung tracing? Stop the artificial respiration for a
few seconds and watch for the heart action to affect the
lung tracing.

Fig. 207. Dissection showing the position and relation of the organs and struc-
tures within the lower pelvis (dog). The pubes were sawed apart and the left side of
the bone shows at L.S.P. A, probe passed into the urethra, Ur; B, probe passed in the
vagina, V; R.S.P., right edge of the (divided) symphasis pubis; V, vulva; F.C., fossa
clittoridis; Cl, clittoris; W. V ., vaginal wall; Bl, bladder; R.L '., right ureter entering the
bladder; R, rectum; Ut, uterus.

ACTIOX OF STRYCHNINE 21 <

The animal will probably be very low by this time. If
it is still alive and the pressure is high enough inject some
other of the opium alkaloids, such as dionine, thebaine or
peronine, and try to counteract this effect by injecting
"epinine' : (1:1000 Burroughs, Wellcome and Company,
New York). ' ' Epinine ' ;t is nearly related chemically and
pharmacologically to adrenaline.

2. After the animal dies, if it is a female, try to pass a
catheter (Fig. 206) through the urethra into the bladder.
Consult Fig. 207 to do this. A catheter made of a very
small glass tube slightly curved at the end is very satis-
factory for this purpose. Could you thus pass a catheter
in a living animal? Isolate the left kidney (or the spleen)
and place it in an oncometer. Place a loop of intestine in
an oncometer (see Fig. 157).

EXPERIMENT XXXI.

Strychnine. (Frog: Action on the Cord.)

1. Pith a frog and attach it to a frog board. Dissect
loose the right tendo Achillis and gastrocnernius muscle
but do not injure the tissues of the thigh. Cut the tendo
Achillis long and drive a carpet tack through the knee joint
region (avoid the artery and sciatic nerve) as shown in
Fig. 208. The tack gives a firm point of attachment for
the gastrocnemius muscle. Then place the frog board in
a large clamp and arrange all apparatus as shown in the
illustration. The drum should have a fairly rapid speed
and the muscle lever should write near the bottom of the
drum (leaving enough space below for the time record).
With a hypodermic needle inject into the dorsal lymph sac
of the frog one cubic centimeter of strychnine sulphate
solution (one cubic centimeter equals one-half milligram).
Wait about three minutes for the drug to be absorbed and
then start the drum. The frog will soon show a marked

218

EXPERIMENTAL PHARMACOLOGY

reaction and it is important to record the first manifesta-
tions of this effect. The drum is kept running and pres-
ently further results will be obtained. When the first
round is completed lower the drum and take a second
round. Blow against the frog and note the results. How
do the contractions obtained on the first round compare
with those of the second! After the two rounds are coin-

Fig. 208. Arrangement of frog and apparatus for recording the contractions of
the gastrocnemius muscle during convulsions. The animal's brain is destroyed.

pleted dissect out the sciatic nerve on the back of the right
thigh (see Fig. 47, page 54) and cut the nerve in two.
Now stimulate the frog (blow against it) and note the re-
sults on your records. What does this show? What can
you say regarding the action of strychnine? Pass a soft
copper wire down the spinal canal and destroy the cord.

ACTION OF STRYCHNIN K

219

What effect lias this on the convulsions? Can you locate
the seat of action of the drug from this experiment? In
what other ways might you test out your conclusions ''.

Fig. 209. Tracing showing th'e action of strychnine on the frog made liy the contrac-
tions of the gastrocnemius muscle as arranged in Fig. 208.

This is the usual method for obtaining graphic records to
illustrate the action of convulsant poisons. This action can
usually be shown quite well on frogs, and since frogs are
cheaper and more easily managed than mammals, they are
generally used for this purpose. The cerebrum is destroyed.

220 EXPERIMENTAL PHARMACOLOGY

EXPERIMENT XXXII.

Strychnine. (Frog: Heart and Vago- sympathetic

Nerve.)

1. Pith a frog and destroy the spinal cord with a soft
copper wire. Examine the beating of the lymph hearts
(see Fig. 66) before and after the cord is destroyed. How
is the beat of these affected? Fasten the frog down, ven-
tral side upward, and dissect out the vagus nerve (Fig. 60).
Arrange to record heart tracings on a moderately slo\v
drum (Fig. 63). Take about one inch of normal tracing
and then stimulate the vago-sympathetic nerve and record
the inhibition and recovery. Take two inches more of the
normal record and repeat the stimulation. Lower the
drum and start a second round. Drop on to the heart a
few drops of strychnine sulphate solution (one cubic centi-
meter equals one-half milligram) and after a few seconds
again stimulate the nerve. This stimulation record should
be directly above the first inhibition record in the first

/

round on the drum. Apply more drug to the heart and
stimulate again. Be sure the stimulating current is not
too strong and do not continue its application to the nerve
any longer than is absolutely necessary or the nerve (or
its endings) may be affected. Apply more drug and then
stimulate again. How is the beat of the heart affected?
Is the muscle of the heart directly concerned in this? What
are the later effects of strychnine on the heart when thus
applied? How does strychnine affect the innervation of
the frog's heart?

EXPERIMENT XXXIII.
Strychnine. (Turtle: Heart and Vagus Nerve.)

1. Pith a turtle and fully destroy the cord by pushing
a soft copper or iron wire (No. 14 or 16) down the spinal

ACTION OF STRYCHNINE

22J

canal. Arrange for taking heart tracings. Dissect out
the vagus nerve in the neck (Fig. 70) and record a nor-
mal inhibition at two places in the lower round on the
drum. Lower the drum and start a second round. Apply
strychnine solution (one cubic centimeter equals one milli-

frr gating fluid

Requlatina
screw clamp

Fig. 210. Greene's method of irrigating the heart.

gram) to the heart with a medicine dropper or according
to Greene's method (Fig. 210) for irrigating the heart. Do
you notice any immediate change in the appearance of the
heart beat? Might this be due simply to the fluid moisten-
ing the heart muscle (as normal salt solution would do) or

222

EXPERIMENTAL PHARMACOLOGY

to temperature changes caused by applying the solution?
How could you avoid these possible effects! Stimulate
the vagus nerve again and record the results. What do
you observe? Apply more drug (the record is made as in
Experiment XXXII) and try stimulating the nerve from
time to time. Are any changes observed? How do you

Fig. 211.' Tracing from the heart of a turtle showing the action of strychnine. At
the short bar the vagus trunk was stimulated and stopped the heart for a brief period.
Subsequently a solution of strychnine was dropped on the heart (at X). The rate of
beat was apparently slightly accelerated. Later (at R.l'.S.) the vagus trunk was again
stimulated but could not slow or stop the heart. What structures were affected by the
drug?

account for this:' How does this compare with the re-
sults obtained by other students? Did the turtle have any
convulsions? How do you explain this?

EXPERIMENT XXXIV.

Strychnine. (Dog: Blood-pressure, Respiration, and
Kidney, Spleen or Intestinal Loop.)

1. Arrange a dog for taking blood-pressure, respiration,
and an oncometer tracing of either the spleen, left kidney

ACTION OF STRYCHNINE

223

or a small loop of the intestine. For the latter record an
instrument similar to the one shown in Fig. 212 may be
used, or the ointment box kidney oncometer (Fig. 157)
may be employed. It is necessary not to get too large a
loop of intestine into the oncometer. Three inches of the
small intestine bent into a small loop is sufficient. It is
very desirable to fasten safety-pins through the ends of
the loop as shown in Fig. 212 to prevent more of the in-
testine from working into the oncometer after the experi-

Pin to fasten
hop of intestine

Opening to receive loop
of intestine

Fig. 212. Glass oncometer for a small loop of the intestine. The safety pins
should be passed through the edges of the wall of the intestine to prevent more of the
intestine from working into the oncometer or any part of the loop from getting out.
About three-fourths natural size.

ment has started. This may also be accomplished by sew-
ing a stitch through each end of the loop with a needle and
thread and tying the thread in the small holes of the onco-
meter. If the gut is allowed to keep crawling more and
more into the instrument as the experiment goes on the
records will soon be spoiled. When the oncometer is ad-
justed then attach the tube for the recording tambour and
close the abdomen securely with hemostats or stitches.

224 EXPERIMENTAL PHARMACOLOGY

Why is this so import ant? The injecting burettes contain
adrenaline and strychnine sulphate (one cubic centimeter
equals one-half milligram).

Adjust all writing points (so they will pass each other)
on the drum. Keep the anesthesia moderately deep and
as even as possible. The oncometer tracing should be the
upper record, the blood-pressure next below, then the res-
piration, and at the bottom of the drum should be the base
line and time marker. The student (and the instructor)
should make careful observations in each experiment to
determine about what sized tambour bowls and what mag-
nification should be used for each organ from which rec-
ords are obtained. This will necessarily vary largely with
different types of tambours and must be determined in
each laboratory from experience.

Take about one inch of satisfactory tracings and then
inject one cubic centimeter of strychnine. What is the
result? Note the time of day. After the pointers return
to normal (which should be in a short time) inject one
cubic centimeter of strychnine again. When the records are
again back to normal inject one-half cubic centimeter of
adrenaline. Do you get satisfactory records? What is
the action of small (therapeutic) doses of strychnine on
the heart and circulation? Slowly, from time to time, in-
ject one cubic centimeter doses of strychnine and allow
the animal to lie perfectly quietly. Is there any change in
the blood-pressure as the action of the drug comes on
slowly? After a time there will be a sudden reaction. Be
sure the drum is going and that you record the result well.
Do not give any more drug for a while then and wait for
further developments. How is the oncometer record af-
fected? How do you account for this? Be sure you are
ready to give artificial respiration if it is needed. Observe
carefully the actions of the face and mouth muscles when
the animal shows most marked symptoms. What is meant
by the expression "risus sardonicus"? Are there any spe-

ACTION OF STRYCHNINE 225

cial pupillary changes ? Do you get any results resembling
a Cheyne-Stokes respiration? Deepen the anesthesia a
little and see if you can depress the action of the drug a
little. Try touching the animal from time to time or jar
the board a little and note the effect. What parts of the
central nervous system are mainly affected? What is the
difference between epileptiform, clonic and tonic convul-
sions? How do you explain these? How long did it take
for the action of the drug to come on? Do you get satis-
factory oncometer tracings! What mechanical factors are
concerned in the production of these? Your apparatus
should be carefully arranged so you can hold the stands,
etc., down firmly on the table to prevent them from being
shaken out of place.

Fig. 213. Glass ureteral canmila with rubber tube connection. About one-half natural size.

Inject some adrenaline into the vein. How does this
affect the animal? Secure records of as many typical
convulsions as you can. Many of these will probably lie
spoiled by movements of the apparatus. Crowd on enough
ether to check the convulsions, then open the bladder and
insert a cannula (or pass a catheter if you can) and close
the abdomen firmly with hemostats. Draw off some urine
and test it for reducing substances. What action will
strychnine have on the glycogen stores of the body? How
is this brought about? What mechanisms are concerned?
How is strychnine excreted? Could you get a positive test
for it in the urine? How long does the drug remain in
the body before it is excreted? What bearing does this
have on the treatment of strychnine poisoning?

226 EXPERIMENTAL PHARMACOLOGY

Kill the animal by a large dose of the drug. AVliat is
the immediate cause of death!

If time permits open the abdomen and dissect out both
ureters (Fig. 162) and trace their course to the bladder.
Could you tie a cannula (Fig. 213) in each ureter and col-
lect the urine from each kidney separately? What is the
innervation of the ureters ?

EXPERIMENT XXXV.

Strychnine. (Ether, Morphine, Chloral Hydrate.) (Dog:
Blood-pressure, Respiration, Oxygen Consumption,

Air Embolism.)

1. Read over carefully the section on oxygen consump-
tion given in Experiment XXVIII, page 177. The ap-
paratus there used is of a very simple form and will be
available in most laboratories. A better but somewhat
more complicated form is shown in- Fig. 172. This figure
shows in addition a special arrangement for measuring
the oxygen each time it is run in. If only enough water be
placed in the pressure bottle to allow 200 or 300 cubic
centimeters (the bottom of the bottle must first be filled up
to the level of the spout) to run down into the graduate* 1
cylinder at a time, then the measuring of this amount of
oxygen before it is run into the pan becomes automatic
and can quickly be done each time. If the oxygen tank
be opened a little oxygen will be forced through the
T-tube into the graduated cylinder. This oxygen is un-
der pressure and will drive the water in the cylinder up
into the pressure bottle. If it is especially desired for
greater accuracy, the bottle can then be lowered to the
level of the graduated cylinder to avoid compression of
the oxygen while its volume is being measured, but this
is not generally necessary, for the compression of the
oxygen in the graduated cylinder by the column of water
up to the pressure bottle will be the same each time and

ACTION OF MORPHINE OX OXYGEX CONST MPTIOX 227

will thus not change separate readings on the drum. This
automatic measuring of the oxygen saves time and should
be done by the student who manages the apparatus on
the drum. The measuring device can also be used on the
simple apparatus shown for Experiment XXA 7 III if de-
sired.

Several very interesting and important actions of cer-
tain drugs can be recorded either with the apparatus
shown in Fig. 172 or with that illustrated in Fig. 175.
Thus the short, rapid, up-and-down movements of the heart
lever records the respiration of the animal even more ac-
curately than does the stethograph around the body. In
addition the actual relative amount of gases passing in
and out of the lungs at any given period can be compared.
And any general change in the volume of the lung con-
tents (contraction or relaxation of the bronchioles) is
well shown. For the latter purpose the short respiratory
excursions of the heart lever on the drum should be mag-
nified to write about one or one and one-half inches in
amplitude.

Arrange a medium sized dog for recording blood-pres-
sure and respiration. The injecting burettes contain
adrenaline and morphine (one cubic centimeter equals
five milligrams). Attach the apparatus for recording
oxygen consumption and take a normal record. This will
involve at least one (and better two or three) complete
notches on the oxygen record. Now deepen the ether anes-
thesia a little (not too much) and see if this slows down
the oxygen consumption. What would you expect the
ether to do? Now r get the animal into a perfectly satis-
factory condition and inject three cubic centimeters of mor-
phine. How does this affect the oxygen record ? Can you
determine whether the observed result is due to a central
or to a peripheral action of the drug! Are there any evi-
dences of bronchial changes! Explain. Inject one -cubic

228

EXPERIMENTAL PHARMACOLOGY

Fig. 214. Tracing showing the action of morphine (and adrenaline) on the rate
of oxygen consumption, on the bronchioles, respiration and blood-pressure in a dog.
At the point marked "bronch. contract." in the upper record it will be seen that the
curve actually turns downward for a short distance. This is due to the marked con-
traction of the bronchioles forcing a part of the supplemental (or reserve) air out of the
lungs. This is probably also reflected on the respiratory tracing by limiting the expan-
sion of the chest. Adrenaline counteracts this broncho-constricting action of morphine
and the three injections of adrenaline each causes a marked increase in the depth of
respiration which lasts approximately during the period that the action of the adrenaline
can be seen on the blood-pressure. Experimentally it has been shown by Guber at
Zurich that animals poisoned by a minimal fatal dose of morphine recover if they be in-
jected with adrenaline. How would you explain the prevention of death (from the
morphine) in these cases by adrenaline?

ACTION OF STRYCHNINE ON OXYGEN CONSUMPTION 229

centimeter of adrenaline. How does this affect the record?
Now give a second dose (three cubic centimeters) of mor-
phine and see what effect this has on the rate of oxygen
consumption. Take three or four notches in the oxygen
record to get the prolonged effects of the drug.

Now arrange for all the drum space you can command
and prepare to record the rate of oxygen consumption
after strychnine. It is to be recalled that the C0 2 exhaled
by the animal may vary quite as much as the rate of oxy-
gen consumption for short periods of time. If a consider-
able excess of C0 2 is excreted it can affect the record
somewhat before it is absorbed. Will this mean a pro-
longation or a shortening of the oxygen record! Will it
add to or subtract from the relative length of time which
a given injection of oxygen will last? Consider this point
carefully in observing the manner in which strychnine
acts on the metabolism.

Arrange all writing points and inject one cubic centi-
meter of strychnine (one cubic centimeter equals one-half
milligram). Wait a little and then repeat the injection
(one cubic centimeter). Continue this at brief intervals,
recording carefully the rate of oxygen consumption all
the time. Be sure the animal cannot shake down your
apparatus when the convulsions come on. Continue giv-
ing strychnine until convulsions are fully developed. How
do these affect the rate of oxygen consumption ? What be-
comes of the oxygen taken up by the animal ? What is the
respiratory quotient? How is it determined? Examine
the pupils during and after a convulsion. What do you
observe? Crowd on ether and see if you can stop the
convulsions. How does this now affect the oxygen con-
sumption? Lighten the anesthesia and empty the strych-
nine out of the burette. Fill the burette with chloral hy-
drate solution (four per cent) and then just after a con-
vulsion inject one cubic centimeter of the solution. How

230 EXPERIMENTAL PHARMACOLOGY

does this affect the convulsions, blood-pressure, respiration
and oxygen consumption! Inject more chloral from time
to time and observe its general action as fully as you can.
If the animal is still alive empty the chloral out of the
burette, then take the burette out of the clamp and place
the upper end of the empty burette in your mouth. Take
the bull-dog off the femoral vein and blow some air into
the vein. Replace the bull dog and watch the action of
the air on the animal. What is meant by air embolism ?
How may it be produced? How does it act inside the
heart chambers'? In the vessels? Blow more air into
the vein if necessary to kill the animal. What conclu-
sions can you draw from this?

Caution. The alimentary canal of the dog contains large numbers of tape
worms and ilieir eggs. If these eggs are swallowed by other animals infection
may occur.

If time permits, dissect out the nerves to the bladder
(and uterus if the animal is a female).

EXPERIMENT XXXVI.
Strychnine. (Student: Reaction Time.)

1. Test the acuteness of hearing of the student who is
to act as the subject of the experiment. Do this by allow-
ing the student to sit at a table (at complete rest) with his
ear or the side of his head against a heavy stand (which
must not be moved later). A watch is now moved away
from the ear of the subject until the ticking can just be
heard (note the position of the watch, i.e., which side is
toward the subject). Mark this distance on the table or
otherwise and then take the watch back to the point
where the ticking just fails to be heard. Mark this point.

2. Xow refer to the arrangement of the apparatus
shown in Figs. 134 and 137 (also see Experiment XIII, 1,

STRYCHNINE AND PICROTOXIXK I*.')!

page 144) and record the subject's normal reaction time
for sight, touch and sound.

3. Take two tubes of oil (or water color) paint, one
white, the other red (other colors may also be used), and
with a brush on a white tile surface (pill tile) make a series
of mixtures of white and red varying only the slightest
degree in color. Also make several just alike. Number
these and let the subject note all those between which he
can just distinguish a difference. Record these results.

4. Now let the subject take a therapeutic dose of
strychnine.

Caul ion. Strychnine is very poisonous. The average dose is oue-sixtielh
of a grain, but many physicians give doses as large as one-thirtieth of a
grain. The drug i s probably best taken in the form of tablets (one-sixtieth
grain) as mistakes are thus less liable to occur regarding the size of the dose.

5. AVait fifteen or twenty minutes (or longer) for the
drug to be absorbed and then again test the acuteness of
hearing, the reaction time for sight, touch and sound, and
the acuteness of color sense with the painted spots on the
tile (be sure these have not changed their color or appear-
ance by drying the spots should be thoroughly dry be-
fore the subject sees them the first time). Has the strych-
nine affected any of these reactions! AYhere did the drug
act to do this! Is the reaction in the nature of a stimula-
tion or a depression? How does this compare with alco-
hol!

EXPERIMENT XXXVII.
Picrotoxine. (Frog: Action on Medulla and Cord.)

1. Examine the arrangement of the apparatus shown
in Fig. 208. Pith a frog (cerebrum only] and arrange it
thus for recording contractions of the gastrociiemius mus-
cle. Under the skin of the back inject one cubic centi-
meter of picrotoxine solution (one cubic centimeter equals

232

EXPERIMENTAL PHARMACOLOGY

i

Fig. 2\>. Tracings from the gastrocnemius muscle of a frog injected with picrotoxine.

one-half milligram). Wait about three to five minutes for
the drug to be absorbed, then start the drum at a moderate
rate of speed. After a short time the frog will begin to
manifest certain symptoms. Record these (on the lower
part of the drum the muscle contraction record should
have an amplitude of about one and one-half or two inches)
and when the first round of the drum is completed lower
it and wait a short while. Then take a second round of
contractions on the upper half of the drum. How do the
last contractions compare with the first ones obtained'?
Have you studied any other drug having a similar action?
How do you explain the results'?

Note. A method for destroying (cutting off) the cerebrum while leav-
ing the medulla intact is described on page 238.

ACTION OF PICROTOXIXE

233

Fig. 216. Tracings from the gastrocnemius muscle of a frog injected with brucine.

EXPERIMENT XXXVIII.

Picrotoxine,* Chloretone. (Dog: Blood-pressure, Respira-
tion and Kidney, Spleen or Intestinal Loop Volume.)

1. Dissolve three grams of chloretone in about eight
cubic centimeters of absolute alcohol. Then add water
until a slight precipitate starts to form. Then add a few
drops more of alcohol to dissolve the precipitate. Now
observe carefully the method of giving drugs to dogs il-
lustrated in Fig. 217. The dog for this dose of chloretone

*Picrotoxine is not often used in medicine.

234

EXPERIMENTAL PHARMACOLOGY

should weigh about eight or ten kilograms. Some dogs
are considerably more susceptible to the drug than others.
One student holds the animal between his knees and
reaches forward to grasp the dog around the nose and
mouth with both hands firmly. The assistant slips a gag
(Fig. 218) into the dog's mouth just behind the eye teeth.

Fig. 217. Method of administering medicine to a dog by means of a stomach tube.

The mouth is now held closed and this prevents the dog
from biting or dropping out the gag, A second assistant
should hold the dog's feet to keep it from scratching.
Sometimes the hind feet must be held also. An ordinary
soft rubber stomach tube (or one-fourth inch rubber tube
with a pointed end) is now passed through the hole in

PRELIMINARY OPERATIONS

the gag and back into the dog's mouth. Push the tube
into the pharynx and wait a little. The animal will make
swallowing movement and these help to direct the tube
into the esophagus. When the tube is safely started it
can be readily pushed down into the stomach.

Cinttion. It not infrequently happens that the tub* 1 passes through the
larynx and into the trachea. If the drug be injected into the lungs the animal
will die in a few moments. This accident must be carefully avoided by using
great caution in getting the tube started far back in the dog's mouth. Also
when the drug is given pour a little of the solution into the funnel and wait
to see what results this has. Breathing sounds may sometimes be heard by
listening at the end of the inserted tube if it is in the lungs but these are un-
trustworthy as similar sounds are often heard when the tube is in the stomach.

fc in. Hole

Rubber tubmq

Fig. 218. Mouth gag for dogs, cats or rabbits. Made of wood.

Allow about ten or fifteen minutes for the drug to act.
If the stomach was filled with food the result will not be
the same as if the stomach was empty. The animal often
becomes very lively and playful at first, but soon gets weak
and unsteady, especially in the hind limbs. After a time
it lies down and becomes drowsy or even unconscious. If
the dose was too small give a second small amount after
fifteen minutes. If the first dose was large enough (and
too marked depression should be carefully avoided) then
give a little ether to bring on complete anesthesia and ar-
ia nge the animal for blood-pressure, respiratory and on-
cometer (kidney, spleen or intestinal loop) tracings. Iso-
late both vagi and place loose ligatures around them. It
may be necessary to give small amounts of ether to keep
the anesthesia sufficiently deep at least in the beginning

236 EXPERIMENTAL PHARMACOLOGY

of the experiment. The injecting burettes contain adrena-
lin and picrotoxine (one cubic centimeter equals one-half
milligram).

When the operations are completed adjust the writing-
points on the drum and take a normal record. Stimulate
each vagus nerve and get records. How does this affect
the respiration and circulation! Now inject one cubic
centimeter of picrotoxine and get records of the results.
Note the time of day. Inject more picrotoxine from time
to time in small doses (one-half or one cubic centimeter)
and keep a close watch on the heart action as shown by
the amplitude of the manometer tracing and by the rate
of heart beat. There should be a slowing of the heart
and a fall of pressure. Both of these should be brought
on very slowly and cautiously by small repeated doses.
(Too large a dose of chloretone weakens the heart con-
siderably and must be watched in this experiment. It also
depresses the medulla somewhat.) The heart beat should
become slow r enough after a time to give a pressure trac-
ing with an amplitude of about ten or twelve millimeters
(one-half inch) to each stroke of the manometer pointer.
When this stage is reached lift up both vagi and tie the
ligatures tightly. Does this affect the heart? If not quickly
cut both vagi centrally to the ligatures. Does this affect
the blood-pressure? Does the respiration remain normal?
How do you account for any changes observed? Did you
get satisfactory records of all these changes? If not why
did you fail ? Can you do better next time ?

Now stimulate the central end of one vagus nerve. How
does this affect the animal ? What nervous paths are con-
cerned in this? Stimulate the peripheral end of the nerve
and note the effect.

Inject more picrotoxine. How does the action here com-
pare with that in the frog? Inject some adrenaline. Do
you get normal effects from this dose? Is the heart

ISOLATION OF THE SCIATIC NERVE

237

slowed! How is the respiration affected! Now give sev-
eral doses of picrotoxine to kill the animal. What is the
immediate cause of death so far as you can judge by this
experiment ?

Fig. 219. A dissection showing the position in which an incision should be made for
finding the sciatic nerve and placing a ligature around it for stimulation.

If time permits dissect out both sciatic nerves from the
outer and posterior aspect of each hind limb (see Fig. 219).
Ligate these nerves loosely and examine them carefully as

238

EXPERIMENTAL PHARMACOLOGY

to size, relations, and the best way to dissect them out,
quickly. It is sometimes of much help to dissect out one
of these nerves and stimulate it to start up the respiration
in an animal that has stopped breathing but in which the
blood-pressure remains fairly high.

EXPERIMENT XXXIX.
Hydrastine. (Frog: Spinal Cord.)

1. With a pair of scissors cut off the front part of the
head of a frog (including the cerebrum) as shown in Fig.
220. Arrange the animal for recording muscular contrac-
tions as shown in Fig. 208.

Cut on dotted line, just anterior to optic lobes

Cerebrum

rr.H.

Fig. 220. Method for destroying (removing) the cerebrum but leaving the rest of the
brain intact in a frog. Note the position of the section.

Under the skin of the back inject one cubic centimeter
of hydrastine (sulphate or hydrochloride) solution (one
cubic centimeter equals two milligrams). Wait two or
three minutes for absorption to occur and then start the
drum at a fairly rapid speed. After a little while there
should be a marked reaction. Try to record the firtt action
manifested by the frog. Finish the first round on the drum,
then lower the drum and take a second round. How do the
reactions shown on the last round compare with those in

ACTIOX OF HYDRASTIXE

239

OK!

to
to

n>

o

o

TO

240

EXPERIMENTAL PHARMACOLOGY

the first round. How do you explain these effects! Cut
the sciatic nerve to the muscle you are using. Is the action
of the drug central or peripheral? Stimulate the muscle
itself directly a few times with single shocks. AVhat does

this show ?

Left Ant Caval vein

.Right Ant Caval vein

Preodnq/ionic rreurdn

Postgongl ionic neuron

nemaAi
Gang lion in
walls ofs/nus.
venosus

sAuricu/dr sleptum

_ from nl
Sinus to auricle I Position of

Hi Auriculo -ventricular

Ho ok from
'Heart lever

YonBezolds Canal/on

m Auricular septum /.,, , _

| 'didders Ganglion

in auriculo-ventricular junction

InfVena cai/a

.Stimulating electrodes

in sino-auricular junction [Crescent]

Sympathetic fibres- dotted lines

Fig. 222. Diagram to show the innervation of the heart in the frog or turtle.

EXPERIMENT XL.

Hydrastine. (Frog: Heart and Vagus Nerve.)

1. Pith a frog and dissect out the vagus nerve (Fig.
60). Arrange to record heart tracings and take one inch
of normal record. Stimulate the vagus nerve and get a
normal inhibition. Then pour on the heart a few drops
of hydrastine sulphate solution (one cubic centimeter
equals five milligrams). How does this affect the beat"?
Stimulate the vagus nerve again and record the result.

HYDRASTINE AND CAFFK1NK 241

What do you observe ? How do you account for this ?
Drop on some more of the drug and again stimulate the
nerve. Is there any change? Now take up the electrodes
and (while the drum is going) turn on a strong (tetaniz-
ing) current. With the extreme tips of the electrodes just
touch for a moment the tissues at the base of the heart
just where the sinus venosus joins the right auricle.
This is about the point where the inferior vena cava pass-
ing forward would bend up toward the right auricle. The
inferior (caudal) border of the tissue which forms the
connecting tube between the sinus venosus and the right
auricle is called the crescent. What result do you ob-
serve following a brief stimulation of this area? (Examine
Fig. 222.)

EXPERIMENT XLI.
Hydrastine. (Turtle: Heart and Vagus Nerve.)

1. Pith a turtle (brain and cord) and take a normal
heart tracing showing vagus inhibition in two or three
places. Lower the drum and start a second round of the
tracing. Drop some hydrastine solution (one cubic centi-
meter equals five milligrams) on the heart. Record the re-
sults and then stimulate the vagus nerve again. What do
you observe ? Apply more drug and stimulate again. Now
stimulate the crescent and note the results. What do you
observe? Can you explain this?

EXPERIMENT XLIL
Caffeine. (Frog: Central Nervous System, Muscles.)

1. Cut off the front part of the head of a frog (Fig.
220) and inject two cubic centimeters of caffeine solution
(the free drug, not a salt, is preferable use a saturated
solution in warm water) into the anterior lymph sac (Fig.

242

EXPERIMENTAL PHARMACOLOGY

i

Z -

= ~

- S

ACTION OF GAITE'INE 243

66). Place the frog in a battery jar and examine it from
minute to minute. Do you note any immediate symptoms?
Touch the muscles of the hind legs from time to time and
note any changes. Does the animal have convulsions? If
so, of what character are they? Keep the animal under
observation until it dies, watching the muscles carefully.
Do you observe any changes in these ? If so, what explana-
tion can you offer?

EXPERIMENT XLIII.
Caffeine. (Frog: Muscle and Nerve.)

1. Pith a frog and isolate both gastrocnemius muscles
and both sciatic nerves (attached to the muscles, i.e., nerve
muscle preparations). Determine the normal minimal
stimulation to cause contraction in nerve A and muscle B.
Pour a small amount of caffeine solution into each of
two watch glasses. Into watch glass A place the nerve
of one of the muscle nerve preparations and into watch
glass B place the muscle of the second preparation.
From moment to moment stimulate the nerve of prepara-
tion A and the muscle of preparation B with single shocks.
What action has caffeine on the vitality of nerve trunks
and of muscle? Which is affected first? Watcli the mus-
cle closely and note any gross changes in appearance, color,
length, solidity, etc. What do you observe? What ex-
planation can you offer? Tease out some small fibers from
muscle A and place them on a slide and examine with a
compound microscope. Can you see the cross striatlons
well? Cover the fibers with a cover glass and while watch-
ing the fibrils closely run a few drops of caffeine solution
under the edge of the cover glass in such a manner that
the solution reaches the fibrils you are watching. What
effect has this on the muscle fibers? How are the cross
and longitudinal markings affected? How do you ex-
plain this?

244 EXPERIMENTAL PHARMACOLOGY

EXPERIMENT XLIV.
Caffeine. (Frog: Heart and Vagus Nerve.)

1. Take a normal heart tracing from a pithed frog
(showing vagus and crescent inhibition). Drop caffeine
(saturated solution) on the heart and record the effects.
Stimulate the vagus nerve and note the action of the drug
on the inhibitory nervous mechanisms. Apply more drug
and again stimulate. Stimulate the crescent also and see
if it is affected. Take several rounds of the tracing on the
drum to get a good insight into the action of the drug on
the heart muscle. How does this compare with the action
on the mammalian heart ?

EXPERIMENT XLV.
Caffeine. (Turtle: Heart and Vagus Nerve.)

1. Repeat the previous experiment on a pithed turtle.
Can vou see anv changes in the tone of the heart muscle

* V

as indicated in your records .'

EXPERIMENT XL VI.
Caffeine. (Man: Reaction Time.)

1. As in Experiment XXXVI (and XIII) determine the
normal reaction time of a student. Then allow the stu-
dent to drink one or two cups of strong tea or coffee (or
take three grains of caffeine powder in capsules) and at
intervals of one-half, one hour and one and one-half hours
later again take the student's reaction time. "\Vhat do
you observe? How do you explain your results? On what
parts of the central nervous system has the caffeine acted to
produce the results observed?

ACTIOX OF CAFFE1XK

245

EXPERIMENT XLVII.
Caffeine. (Frog: Muscular Work.)

1. Pith a frog and ligate the right thigh tightly so as
to shut off the circulation. Fasten the animal down on a

Very fine copper
wires, attached to
tack and to tendo
jchillis

Fig. 224. Arrangement of a frog and apparatus for recording "fatigue tracings"
from the gastrocnemius muscle. The drum should have a slow speed. (For descrip-
tion see text.)

board as shown in Fig. 224. Isolate the tendo Achillis
of the right leg and arrange as illustrated for stimulating
with single shocks. The primary current is best inter-
rupted by a metronome as illustrated, but if this is not

246

EXPERIMENTAL PHARMACOLOGY

available then a student can interrupt tlie primary cur-
rent with a simple key by hand (once in one or two sec-
onds). The drum must have a slow speed. The second-
ary shocks are carried directly to the muscle by very fine
copper wires one of which is attached to the carpet tack
which is driven through the frog's right knee into the frog-
board to hold the upper end of the gastrocnemms muscle
firmly in place when the muscle contracts. The other wire
is tied to the tendo Achillis. Now inject into the dorsal
lymph sac one cubic centimeter of five -tenths per cent caf-

Rubber tube
- w/re

I

Cannula with points for cats* rabbits

Point for doqs

Fig. 225. A method for making cannulas with separable points. One end of the
"T" of a glass (5/16 inch) T-tube is cut off short and short glass points are attached
liy means of a piece of rubber tubing. It is vastly easier to make the small points than
to blow a T-tube and to make a cannula entirely of glass. (The points illustrated are
larger than they should be for rabbits and cats. )

feine solution (Greene) and allow this to be absorbed
while the experiment is going on.

When all adjustments are made start the drum and
record a normal ''fatigue curve'! from the right gastroc-
nemius. (For a description of fatigue curves see any
manual on experimental physiology.) This curve should
be taken on the lower half of the drum.

c
o

V

B

o

-

t.-

rt

^
o

u

c

V

o

-

CAFFEINE DIURKSIS '247

When the muscle is exhausted then ligate the left thigh
tightly and drive a second carpet tack through the left
knee to hold the left gastrocnemius firmly. Isolate the
left tendo Achillis. Disconnect the stimulating wires, re-
move the frog hoard from the large clamp and turn the
frog board around on a perpendicular axis so that the frog
will be on the side away from the apparatus. Also remove
the large clamp, turn it over on a horizontal axis and re-
attach it to the stand. Replace the frog board. The left leg
of the frog will now occupy practically the same position
that the right leg formerly had. Attach the stimulating
wires and connect the tendon to the muscle lever. The
load, magnification, tension, etc., of this muscle must be
the same as that used with the right muscle. About twenty
minutes should now have elapsed for absorption of the
caffeine.

Start at the beginning of the upper half of the drum
and record a fatigue curve of this muscle, which will now
show the effect which caffeine has on muscular work. The
rate of stimulation should not vary (once in one or two
seconds) for each curve. How does the normal fatigue
curve compare with the caffeine curve? What conclusions
can you draw?

EXPERIMENT XL VIII.
Caffeine. (Rabbit: Diuresis, Cervical Nerves, Depressor.)

1. Dissolve two grams of urethane in about twenty-five
cubic centimeters of water. Select a full grown rabbit
and with a catheter used as a stomach tube inject the
urethane into the rabbit's stomach. [Pass the tube
through the hole in a wood gag (Fig. 218) held in the
animal's mouth.] Wait about ten or fifteen minutes for
the drug to be absorbed and then give the animal a little
ether to bring on complete anesthesia. Use great care in
this for rabbits die very readily. Insert a tracheal can-

248 EXPERIMENTAL PHARMACOLOGY

nula (one-fourth inch diameter) and connect up the ether
bottle (or anesthetic device shown in Fig. 116). Use the
great e*t care in giving the ether not to kill the animal. In-
to the femoral vein tie a very small injecting cannula (Fig.
18) connected to a burette containing caffeine solution
(.5/t)- Record the respiration on the drum.

Open the abdomen over the bladder and insert a bladder
cannula (Fig. 23). Arrange the cannula to empty into a
graduated cylinder and when all preparations are made
wait ten or twenty minutes to record the normal rate of
urine secretion. Test this with Fehling's solution. Then
cautiously inject one-half cubic centimeter of caffeine so-
lution into the vein. "Watch the effects of this on the
respiration closely. From time to time as the animal will

rubber tube

Washout

Fig. 227. An easily made glass cannula showing a sliding rubber tube which may
be used to open or close the small opening blown in the side of the tube and used as
a "washout."

tolerate it inject more caffeine in one-half cubic centimeter
(or smaller) doses. Is there any change in the rate of
urine flow? Collect the urine for each ten minute inter-
val. Test for reducing bodies again. Is sugar present !
If so, how do you account for it!

If you have time, consult Fig. 226 to learn the ar-
rangement of the vagus, sympathetic and depressor nerves
in the neck of the rabbit, and then carefully dissect out
these nerves. Using a very small arterial cannula (Figs.
22.") and 227) connect the right carotid artery to the ma-
nometer and take a blood-pressure tracing. Stimulate tlu-
depressor nerve (peripherally) and note the effect. How
do you explain this result? Inject more caffeine and see if

CAFFEINE AND SODIUM SULPHATE 249

you can obtain any idea of the action of the drug on the
heart and circulation. Kill the animal with a large dose
of caffeine. After the animal is dead dissect out the vagus,
sympathetic and depressor nerves in the other side of the
neck.

EXPERIMENT XLIX.

Caffeine, Sodium Sulphate. (Dog 1 : Blood-pressure
Diuresis, Respiration, Sciatic Nerve.)

1. Dissolve three or four grams of chloral hydrate in a
little water and inject the solution into the rectum of a
medium sized dog. See that the solution does not run
out again immediately after injection. In ten minutes
anesthetize the animal fully with ether (or etherize the
animal at the start and omit the chloral or give it by stom-
ach it is advisable to give the chloral, however). Ar-
range to record blood-pressure, respiration and the rate of
urine flow. Place caffeine (.5%) and adrenaline in the in-
jecting burettes.

Open the abdomen and lift up the bladder. At the pos-
terior side of the base of the bladder you will find the
ureters entering the bladder from each side (see Fig. 1(52).
Pick up the ureters and place in each a ureteral cannula
(Fig. 213) and arrange to record the rate of urine secre-
tion by obtaining a record on the drum of the drops fall-
ing from the cannulas. To do this arrange two tambours
as shown in Fig. 228 in such a manner that each drop of
urine falls on a small metal disc attached with wax (colo-
phonium or ceiling wax) to the writing point of the first
tambour. The second connected tambour records these
drops on the drum.

Consult Fig. 219 and dissect out the sciatic nerve in one
hind limb. While recording blood-pressure and respira-
tion stimulate the nerve with a medium strength Faradiz-
ing current. What do you observe ? Can you think of a

250

EXPERIMENTAL PHARMACOLOGY

condition in which this procedure might be of help in re-
viving 1 an animal '? Try this on the next animal you have in
which the respiration ceases, especially if the blood-pres-
sure remains fairly high.

Adjust all writing points, allow the animal to return to
normal (keeping the anesthesia as regular as possible) and

Drop

Metal plate

--Hatfeck -

Fig. 228. Arrangement of two tambours to form a drop recorder.

wait ten or twenty minutes to record the normal rate of
urine flow. When this is obtained (not a drop of urim-
may have been secreted during this period, in which case
simply watch for the flow to start up) then proceed to give
the caffeine. Watch for the effect on respiration and the
circulation. Inject one cubic centimeter of caffeine.. What
do you observe? Increase the dose if the animal will

ACTION OF SODIUM SULPHATE

251

<*>

(I

n
o

-t

CL

O

tu -o
< n

It O

O 11

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-u^

O '/i

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03"

o

pi C.
O) O

-W

a t-.
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252 EXPERIMENTAL PHARMACOLOGY

stand it and continue giving the drug until several centi-
meters are injected. Wait a while to observe the effect
on urine flow. This often fails in dogs. Why? Will the
chloral influence the result in any way!

Wait for fifteen or twenty minutes for the caffeine to
act. Be sure the dose given was large enough. Then al-
low the animal to become as nearly normal as possible and
get a new normal rate of urine flow. Test the urine for
sugar. What do you observe! Explain.

Now empty the caffeine out of the burette and fill it with
four per cent sodium sulphate solution. Inject one cubic
centimeter. Increase the dose rapidly (twenty cubic cen-
timeters or more may be given at a time often without
killing the animal) and watch the effect on blood-pres-
sure, respiration and urine flow. What do you observe I
How does this compare with the action of caffeine! If
the animal is still in fair condition substitute a four per
cent solution of sodium phosphate (or nitrate or chloride)
for the sodium sulphate and inject a considerable quantity
of this salt. How is the rate of urine flow affected! What
theories of urine secretion do you know! On the basis of
these explain the action of the drugs injected. Keep a
record of the amount of solution injected in each ten min-
ute interval and see if you can collect an equal volume of
urine in a beaker in the same time. This can sometimes
be done, especially with rabbits. Kill the animal by a
large injection of one of the salts mentioned (watching the
urine flow as the drug is acting), then dissect out the pan-
creas and see if you can find its lower duct (Figs. 244 and
L'45). Could you put a cannula in the duct while the ani-
mal was alive ? Dissect out the gall bladder, the cystic
duct, and the common duct. What are the relations of the
pancreatic ducts and the bile ducts as they pass through the
wall of the intestine .'

DIURETINE AND AGUltlXr.

EXPERIMENT L.

Diuretine, (Sodium-theobromine-salicylate), Agurine,
( Sodium-theobromine-acetate ) . ( Rabbit : Diuresis
and Respiration.)

1. Give by stomach two grams of urethane dissolved in
twenty-five cubic centimeters of water to a good sized rab-
bit. Wait ten minutes for the drug to be absorbed and
then give the animal a little ether to complete the anes-
thesia. Arrange to record (or collect or both) the drops
of urine as they fall from a bladder cannula (or from two
ureteral cannulas). Place a cannula in the femoral (or
jugular) vein and connect up a burette. Fill this with
diuretine one per cent (or agurine, one per cent). Arrange
to record the respiration. Count the pulse rate per minute.

When all preparations are made wait ten or twenty min-
utes to obtain the normal rate of urine flow. Then inject
one-half cubic centimeter of diuretine [(Knoll and Com-
pany, 45 John St., New York) or agurine] and record the
effect on the respiration. Count the pulse rate and see if
it is affected. Now give more of the drug from time to
time and try to bring on the effect gradually, watching
carefully not to kill the animal by an overdose. What do
you observe! How do you account for this? If your drop
recorder does not work well then let a student operate
the recording signal magnet by means of a simple hand
key placed in series with a dry cell and the signal magnet.
The student can make and break the current each time a
drop falls. If you are skillful enough you can make a de-
vice to record each drop by electrical contact. But do not
spend too much time at this.

When you have obtained as marked results as possible
from the diuretine (or agurine or both) then if the rabbit
is still in suitable condition fill the burette with one of the

following solutions:

25-t EXPERIMENTAL PHARMACOLOGY

2% sodium nitrate,

2% sodium phosphate,

2% sodium chloride,

2% ammonium chloride,

2% ammonium acetate.

Arrange to observe the full action on urine secretion and
cautiously inject one-half cubic centimeter (or less) of the
solution in the burette. With great care gradually inject
more of the solution from time to time as rapidly as the
animal can tolerate it. What effect has this on the urine
floAv ? Continue the administration as long as satisfactory
results can be obtained.

EXPERIMENT LI.

Urea, S. A. Matthews' Solution, or Saline Diuretics.
(Rabbit or Cat: Diuresis.)

1. Repeat the above experiment with a rabbit or cat (us-
ing two grams of urethane for an average sized animal, or
1.7 cubic centimeters per kilogram of paraldehyde for a
rabbit Edmunds) but after securing the normal rate of
urine flow begin to inject one of the following:

A. Urea (5% solution).

B. S. A, Mattheic's solution:
NaCl, 3.67 grams.
Na,S0 4 , 10.1 grams.
Sodium Citrate, 3.36 grams.
CaCL, 0.136 grams.
Water, 1000 c.c.

C. Three per cent solution of any of the following:
Sodium sulphate.

Sodium phosphate.
Sodium nitrate.
Ammonium nitrate.

ACTION OF CURARA 1_ } .V)

Sodium chloride.
Sodium iodide.

Use great care in making the injections. Begin with
very small doses and inject more as the animal is able to
tolerate it.

What conclusions can von draw with reference to the

*/

diuretic action of these substances? How do they act?

EXPERIMENT LIT.

Curara. (Frog: General Action, Claud Bernard's

Experiment.)

1. Pith a frog (cerebrum only) and make a small incision
over the back of the right thigh (see Fig. 4-7). .Dissect up
a short length of the sciatic nerve. Do not cut or injure the
nerve. Pass a thread beneath the nerve and tie off the tis-
sues of the thigh tightly so as to completely stop all circula-
tion in the right (gastrocnemius) muscle and foot. With
single shocks stimulate the exposed nerve once or twice to
see how the muscles act in the isolated part of the leg. Also
stimulate the tissues at the back of the head over the upper
end of the cord once or twice to get the normal reactions.
Put a drop of acetic acid on the left hind foot and see if the
animal moves the limb. Brush off the acid. Count the rate
of lymph heart beats.

Into the ventral lymph sac inject one cubic centimeter of
a saturated solution of curara. Wait three. minutes and
then begin to retest the reflexes from time to time as the
drug is absorbed. How is the rate of beat of the lymph
hearts affected? Will the animal jump when stimulated?
As the action of the drug becomes very marked stimulate
again the exposed sciatic nerve. (Keep the nerve moist with
salt solution where it is exposed.) Apply a drop of acetic
acid to the skin of the back. Is there any response? If so,
where ? Stimulate the upper end of the cord. What muscles

256

EXPERIMENTAL PHARMACOLOGY

respond? Stimulate the left gastrocnemius (through the
skin) directly. Does it contract? What conclusions can
you draw ? Where does curara act? Does your experiment
prove the nerve trunks are not paralyzed ? Are the sensory
nerve endings paralyzed J ? Does your experiment give you a
chance to test this point? Count the lymph heart rate

Fig. 230. Tracing showing the action of a solution of curara dropped on the heart
of a frog. Lower line normal, showing the inhibition caused by stimulation of the
vagus trunk. Second line, curara was applied at "x" and the vagus was again stimulated
as shown by the short line and legend. Third line, the application of the drug was con-
tinued and the vagus trunk was again stimulated as indicated. No noticeable results fol-
low the stimulation. Why not? Fourth and fifth lines, application of the drug was con-
tinued and its action on the heart is shown.

again. What conclusions can you draw from this ? What
is the action of curara on the central nervous system? (See
McGuigan : Journal of Pharmacology and Experimental
Therapeutics, 1916, viii, p. 471.)

Do you know of any other substances possessing an ac-
tion on motor nerve endings in striated muscles like curara
does ? How does this drug differ from atropine in its action
on nerve endings ?

Center
cram'

Facial nerve^N.
Cerebellum^
GlossopharynqeaL nerve-

( N. IX) ^ '*-
Medulla oblongata

c ganglion

tympani nerve

"

id duct
(Benson's)

,

Jacobsons
nerve

Lingual nerve

Chordo-lingual

triangle

tympani
branches

Superor
cervical gang.

'Submaxillarv

Electrodes

(Small amount of thick saliva
vaso-con3tric.tion

Parotid gland

Cord

Thoracic
nerves

l

duct(Wharton's)

ublingual
ducf
(Bartholin's)

Electrodes
( Large amount of thin
saliva,
vaso-dilatation

Sublingual gland

Vaso constrictor fibers
sympathetic secretory fibers

Outgoing sympathetic
rami communicantes

Post qanglionic fibers are
dotted thus

Fig. 231. Diagrammatic representation of the innervation of the salivary glands in

the dog.

ACTION OF CURARA 257

EXPERIMENT LIIL

Curara. (Frog: Heart and Vago-sympathetic Nerve.)

1. Pith a frog and arrange to take a heart tracing.
Stimulate the vagus nerve and get a normal inhibition.
Drop on the heart a few drops of a saturated curara solu-
tion. What do you observe? Now stimulate the nerve
again and record the result. Has any change been pro-
duced! If not apply more curara and stimulate again.
Now stimulate the crescent and record the result. What
do you observe ? How do you explain this f Apply more of
the drug to bring out the later action on the heart.

EXPERIMENT LIV.

Curara. (Turtle: Heart and Vagus Nerve.)

1. Repeat the above experiment on a pithed turtle.
How do the results obtained with this animal compare with
those from the frog? What is the innervation of the tur-
tle's heart? How does it differ from that of the frog?

EXPERIMENT LV.

Curara, Strychnine. (Dog or Cat: Blood-pressure, Respi-
ration, Urine, Sciatic Nerve. Dog: Salivary
Ducts and Nerves.)

1. Weigh a medium-sized dog and give it by stomach
three hundred milligrams of chloretone per kilo of body
weight. Dissolve the chloretone in ten cubic centimeters of
alcohol (absolute) and dilute the solution as much as pos-
sible with water. Add a little alcohol to redissolve any pre-
cipitate formed. After ten minutes etherize the animal and
attach it to the operating board. Arrange to record blood-
pressure and respiration (stethograph). The injecting bu-

258 EXPERIMENTAL PHARMACOLOGY

rettes contain strychnine (one cubic centimeter equals one-
half milligram) and adrenaline. (If a cat must be used give
it two grams of urethane in twenty-five cubic centimeters
of water by stomach, or give 1.7 cubic centimeters of paral-
dehyde per kilogram of animal Edmunds.)

Insert a bladder cannula into the fundus of the dog's
bladder, draw off a little urine and test it with Fehling's
solution. Do you get a reduction ? If so how do you explain
it? Now consult Fig. 219 and dissect out the sciatic nerve
using great care not to disturb the vessels of the leg. (These
are carefully avoided so the curara can be well distributed
to the muscles innervated by the sciatic.) Stimulate the
sciatic with a medium strength Faradizing current and
note the effect on respiration and blood-pressure and on the
muscles of the leg below the point of stimulation.

Beneath the skin of the back or side inject with a hypo-
dermic syringe twenty cubic centimeters of a saturated solu-
tion of curara (Merck's). This dose is exceedingly large if
the drug is pure, but it is usually impossible to get a first-
class preparation of the substance in this country. Note
the time of day and observe how long a time is required for
the drug to act (slow or Aveaken or stop the respiration).
How is the blood-pressure affected? (It may be necessary
to give more of the drug later.) Be on the watch for the
respiration to become shallow. How does this affect the
blood-pressure? Be sure to keep the anesthesia going if
the dose of chloretone was not sufficient to completely main-
tain the narcosis. This drug is supposed not to prevent
sensation, hence the animal must be kept anesthetized. As
the respiration begins to fail give artificial respiration.
This must be maintained during the remainder of the ex-
periment.

From time to time briefly stimulate the vagus nerve with
a medium tetanizing current and note the effect on the
heart. Do you observe any change after the action of the
drug has become very marked? Is there any change in

ACTION OF CURARA 259

the reaction of the pupil when the vago-synipathetic trunk
is stimulated 1 ?

Collect a few drops of urine and test with Fehling's solu-
tion. Is there any reduction? How do you account for it?

Pick up the sciatic and stimulate it again with the same
strength of current as that used the first time. Do you get
a response? What conclusions can you draw? How does
electrical stimulation compare with the natural nervous im-
pulse?

Now get the animal in as good condition as possible and
while recording the blood-pressure inject one cubic centi-
meter of strychnine. Follow this up rapidly with more
injections as fast as the animal can well tolerate the drug.
Watch for convulsions. Do you get these? What muscles
are affected by curara ? What ones are not affected ? Does
the action of strychnine extend to any of those not affected
by curara? If so what manifestations of this action would
you expect? Are these present? Is there any change in
blood-pressure? If so how long is this change present as
compared with the action of strychnine in a noncurarized
animal? Explain this. Stimulate the vagus and sciatic
nerves again and note the results on the heart and leg mus-
cles. Is there any change in blood-pressure when the sciatic
is stimulated? If so how does this compare with your nor-
mal record? What structures are involved and how are
they affected (Bayliss: Journal of Physiology, Ixxx, 353)?

Dog. Consult Figs. 237, 238, 239 and 240 and dissect out
the submaxillary and sublingual ducts. Also dissect out the
chorda tympani nerve. For the general distribution of
nerves to the salivary glands see Fig. 231. If the ainmal is
still in suitable condition try to insert a cannula (Fig. 102)
into Wharton's duct as indicated in Figs. 238, 239, and 240.
Stimulate the chorda tympani nerve and see if you can ob-
serve any effects on the rate of salivary secretion. What
action has curara on the salivary apparatus? Have you
demonstrated this? Kill the animal with a large dose of

260 EXPERIMENTAL PHAEMACOLOGY

strychnine. After death dissect out the ducts and chorda
tympani nerve on the opposite side. Can you easily dif-
ferentiate between the two ducts? Can you locate the
chordo-lingual triangle? Cut out (label} both eyes and
place them in thirty per cent alcohol. Save for dissection
later.

EXPEEIMENT LVI.

Coniine. (Frog 1 : Heart and Vagus Nerve.)

1. Pith a frog, arrange for taking a heart tracing and
stimulate both the vagus trunk and the crescent. Get rec-
ords showing the inhibition from each of these. Drop two
or three drops of a one per cent coniine solution on the
heart. How does this affect the record? Now stimulate the
vagus and crescent again and record the results. What do
you observe ? How do you explain this 1 What other struc-
tures are similarly affected by coniine ? Make a diagram of
the innervation of the heart (Fig. 222) of the frog in your
permanent note book and indicate on it the structures af-
fected by coniine and state the nature of this action. Apply
sufficient coniine to the heart to bring it to a standstill. Do
you know of any other drugs that act like coniine 1 Watch
for these later.

EXPEEIMENT LVII.

Coniine. (Turtle: Heart and Vagus Nerve, Lungs and

Sympathetic Nerves.)

1. Repeat Experiment LVI on a turtle and secure rec-
ords to show the action of the drug. After a record show-
ing the specific action of the drug on the ganglia has been
obtained (how would you prove this?) then unhook the
heart lever and remove the turtle from the drum. (It is
often advisable to use a fresh turtle for this part of the ex-
periment. Large turtles are preferred.) Consult Fig. 232

To tambour

Hook

. bronchus

Glass can n ula
in trachea

Liqature on
nerves

Leg

bone

(cut)

Fllunq

partially

inflated

Heart
L lunq
partially
inflated

Position occupied by hind
limbs (removed)

Fig. 232. A turtle with the brain and spinal cord destroyed and with the plastron
and most of the viscera, limbs and skeletal muscles removed to expose freely the partially
inflated lungs. A bull-dog is placed on the right bronchus to exclude the right lung
from communication with the recording tambour which is connected with the left lung
by means of the glass cannula tied in the trachea. The electrodes are shown placed
under the left vagus trunk. The heart beats freely. Stimulation of the vagus nerve
causes a marked contraction of the corresponding lung. (See Fig. 233 for arrangement
of the recording apparatus.)

262

EXPERIMENTAL PHARMACOLOGY

and note carefully what has been removed. Cut the plas-
tron loose at each side and remove it. Lift up the intestines
and liver and with great care dissect them loose from the
lungs. To do this put a cannula (Fig. 233) into the trachea
and attach a rubber tube. Then with the mouth blow the
lungs up as indicated in the illustration and clamp off the
rubber tube. This holds the lungs partially distended and

Fig. 233. Arrangement of apparatus with a turtle held in a Higgin's turtle frame
(of 3/8 inch iron rod with hooks at the corners to which the limbs are tied) for record-
ing lung contractions. A very sensitive large-bowled tambour with a large magnification
is used, and the lungs are partially inflated by forcing a little air (with the mouth) into
the side outlet of the tubing. This puts the tambour and the lung both under moderate
tension and in direct communication. When the lung contracts the tambour pointer
rises but when the lung relaxes the pointer descends as the rubber membrane on the
tambour forces the air back into the lung. Drugs are conveniently administered by in-
jection into the heart with a fine pointed hypodermic syringe.

greatly aids in the dissection. Use great care not to punc-
ture the lungs. If you do this, find the hole, lift up the
edges of the opening and tie a ligature around the puncture.

TURTLE LUNG TRACING

263

When the entrails are removed then cut out all the skeletal
muscles you can including the entire hind limbs and most of
the muscles of the fore limbs. This exposes the lungs prac-
tically free from skeletal muscles.

Connect the tracheal cannula with a tambour (very sensi-
tive, medium-sized bowl) and bring the writing point on to
a slow drum. Observe the way the bull-dog is placed in the

Fig. 234. Tracing showing the contraction of the left lung of a turtle when the left

vagus nerve was stimulated electrically.

figure. In a similar manner clamp off one bronchus and
then pick up the main trunks of the vagus and sympathetic
nerves on the opposite side well up in the neck. See that
the lung is partially inflated and the tambour under a slight
tension. Start the drum, and with a fairly strong tetaniz-
ing current stimulate the vagus and sympathetic trunks

264

EXPERIMENTAL PHARMACOLOGY

(see Fig. 234). What do you observe ? What are your con-
clusions 1 Consult your text-book on physiology for further
explanation regarding the innervation of the lungs. Now

imiiimiiiiiiiiiiiiminiiiiiiiisiiiiiniiiifiiiimiiiiiiiiiiii

Fig. 235. Lung and heart tracings from a turtle showing the effect of electrical
stimulation of the right vagus nerve (first contraction and inhibition) and of mechanical
stimulation (tearing) of the same nerve (second and third records).

make a careful dissection of the nerves (and sympathetic
branches) on the opposite side of the neck. Make a sketch
of these nerves for future reference.

It is exceedingly desirable in making the preliminary dis-
section to remove as much as possible of the skeletal mus-
culature. This prevents movements which may be confused
with the lung contractions.

ACTION OF CONIINE

Lachrymal

Maxillary
nerve

(Meckel's
Spheno-yatatine
ganglion

Geniculat
ganglion

Internal

carotid

plexus

Superior cervical!

Spinal

cord

I -Thoracic

Semilunar
(Gasserian)
ganglion

Corpora
Quadrigemina

Trigeminal
nerve
(N.V)

Facial nerve
N.VII)

Centers for
lachrymal
secretion

Medulla
oblongata

Out-going sympathetic
ram! communicantes

Hutleck

Fig. 236. Diagrammatic representation of the innervation of the lachrymal glands.

EXPERIMENT LVIII.

Coniine. (Dog: Blood-pressure, Respiration, Salivary
Glands and Kidney, Spleen or Intestinal Loop.)

1. In the usual manner prepare a dog (ten or twelve
kilos) for recording blood-pressure and respiration. The
animal may be given morphine, twenty milligrams (one
cubic centimeter of two per cent solution) per kilogram of
body weight half an hour before the operation, or ether
alone may be used. The injecting burettes contain coniine

266

EXPERIMENTAL PHARMACOLOGY

(one per cent) and adrenaline. (Poor samples of coniine
are frequently obtained.) Isolate and ligate loosely .both
vago-sympathetic nerves.

Consult Figs. 237, 238, 239, and 240, and dissect out Wliar-
ton's duct. Place a cannula (very small) in the duct and
fasten it with a ligature (thread). Dissect out the chorda
tympani nerve and when you can see it clearly lying across
the tip of the sublingual gland then place the ends of the

Fig. 237. A dissection showing the position and extent of the first incision for ex-
posing the chorda tympani nerve and the ducts from the submaxillary and sublingual
glands.

electrodes on the nerve and stimulate it. Do you get a nor-
mal result? If not why did you fail? (Dissect out the op-
posite duct and nerve if necessary.) Consult Fig. 231 for
the general distribution of nerves to the gland. Are any
other glands thus innervated? If so what ones?

Open the abdomen and place an oncometer on a kidney
(left), spleen or an intestinal loop. Close the abdomen with
hemostats and arrange all writing points in the following

Position of

Ltnqual nerve under

myiohyoid muscle

Tear across
fibres of
my/o hyoid
here

Ant belly

of digastric m.

Posmon of

Myiohyoid
muscle

hypoglossal nery
under mvlobvoid

'o ether
bottle

Angle of jaw
Trachea

Fig. 238. Dissection showing the position and relation of the hypoglossal and
lingual nerves (dotted and colored yellow) beneath the thin, band-like myiohyoid muscle
which is to be torn across with a blunt probe (not with a scalpel) to expose the nerves
(and ducts) beneath.

Torn edqe of
myiohyoid muscle

Diqastric
muscle

Sublinqusl duct
(Bartholin's)

Submaxillary duct
(Wharton's)

Lingual nerve

ylohyoid muscle
displaced mesially

Hypoqlossal nerve
ein

Vein,
in fascia

Fig. 239. The myiohyoid fibers have been torn across and the two ducts and the
lingual and hypoglossal nerves are exposed.

Insertion of cannula
info Wharton's
duct

Mylo-
hyo/d
muscle

Hvpoglossaf and
ingual nerves
displaced
mesially

Sub-
Itnguai
gland

Chordo-lmgual

horda i-ympan!
nerve. '

loose liqature
( thread)

Fig. 240. Exposure of the chorda tympani nerve, Wharton's duct and Bartholin's duct.
Method of procedure for inserting a cannula into Wharton's duct.

ACTION OF CONIHSTE 267

order from above down, oncometer, blood-pressure, respira-
tion, base line and time signal. Take a normal record, in-
cluding a vagus stimulation, and then inject one cubic centi-
meter of coniine solution. Watch the pupils as the drug is
injected. Do you obtain satisfactory results? How did the
heart beats appear just after the drug was injected? How
do you account for this? Stimulate the vagus nerve again
and record the result. Has any more saliva been secreted 1
How do you account for any changes in the oncometer trac-
ing. Inject a small dose of adrenaline to see if your appa-
ratus, etc., is working satisfactorily.

Inject a second dose of coniine. This may be larger or
smaller than the first dose depending on the reactions
brought about by previous injections. Do you get a fall in
blood-pressure! If so how do you explain it? If you get a
rise what is the cause of this? Stimulate the vagus again
and explain its action on the heart. Observe the corre-
sponding pupil while the nerve is stimulated. Stimulate the
chorda and see if any change has been produced in it as
shown by the salivary secretion. Explain any changes ob-
served. From time to time give more coniine as the animal
will tolerate it. Be ready to apply artificial respiration if
necessary. At intervals stimulate the vagi and chorda and
if a response fails to be obtained explain its cause. Then
follow the course of the chorda tympani back under the jaw
bone as far as you can (do not injure the duct) and finally
push the electrodes far down into the hilus of the gland and
stimulate. Can you cause any visible increase in the flow of
saliva by this procedure ? What is the purpose of this part
of the experiment? Give some adrenaline and see if the
pupils respond normally.

Open the abdomen, follow the right side of the stomach
around posteriorly and pick up the duodenum. In the
angle between this and the stomach ( inferiority) is located
the pancreas. Eefer to Figs. 244 and 245 and find the lower
end (tail) of the pancreas. Follow this to the place where

268 EXPERIMENTAL PHARMACOLOGY

its attachment to the duodenum begins. The large duct
(Fig. 245) opens into the intestine about one-half inch
above this attachment. To find the duct take a probe and
with great care gently dissect the anterior edge of the pan-
creas away from the wall of the intestine. The duct will be
found passing from the substance of the pancreas obliquely
downward and inward through the intestinal wall. Pass a
ligature beneath the duct as shown in Fig. 245 and then
open the duct in the substance of the bowel wall. Insert a
small cannula and tie it in with the ligature. Attach a short
rubber tube to the cannula and bring it outside the abdomen
which is now closed with hemo stats.

Give another dose of coniine and see if you get any secre-
tion from the pancreas. Stimulate the vagi nerves and note
any effect on pancreatic secretion. Kill the animal with a
big dose of coniine. Immediately after death quickly open
the thorax, pick up the phrenic nerves and stimulate them
with a weak tetanizing current. Does the diaphragm con-
tract? What theories do vou know concerning the cause of

V

death under coniine (Cushny: Journal of Experimental
Medicine, i, 202) ? Dissect out the small duct of the pan-
creas. What is the innervation of the pancreas? How is
its secretion controlled?

EXPERIMENT LIX.
Atropine. (Frog: Heart and Vagus Nerve.)

1. Pith a frog and take a normal heart tracing showing
the effects of stimulating the vago-sympathetic nerve and
the crescent. Then while the drum is going pour two drops
of atropine sulphate solution (one cubic centimeter equals
one milligram) on the heart. After a few seconds stimulate
the vagus trunk again. What do you observe ? How do you
explain it? Now stimulate the crescent. What do you ob-
serve? How do you explain this?

2. Cut out both of the frog's eyes. Examine the size

ACTION OF ATROPINE 269

of the pupils carefully. Place one eye in a watch glass full
of normal salt solution and the other in atropine solution.
Place both glasses aside for ten or twenty minutes. Then
again compare the size of the pupils. Do you note any va-
riations? Explain the results.

EXPERIMENT LX.
Atropine. (Frog: Muscle and Nerve.)

1. From the frog used in Experiment LIX prepare two
muscle nerve preparations from the sciatic nerves and gas-
trocnemius muscles. Fill a watch glass with atropine
solution and place the nerve of preparation A and the
muscle of preparation B in the solution. From time to time
stimulate both nerves with single shocks and determine
whether or not atropine affects either nerve trunks or stri-
ated muscle. Compare this with the action of curara.
Stimulate the muscles directly a few times. What con-
clusions can you draw?

EXPERIMENT LXI.
Atropine. (Turtle: Heart and Vagus Nerve.)

1. Repeat the experiment on the heart and vagus inner-
vation described in Experiment LIX, 1, on the turtle. What
conclusions can you draw from your results?

EXPERIMENT LXII.

Atropine. (Cat, Guinea Pig, Rat, Dog, Pigeon, or

Chicken: Pupil.)

1. Secure a dog, guinea pig or rat and a pigeon or
chicken. Into the right eye of each animal pour several
drops of a one per cent solution of atropine with a medicine
dropper. Place the animals aside and examine from time

270 EXPERIMENTAL PHARMACOLOGY

to time to see if any changes are produced in the eyes. If
so what explanation can you offer. If no change is pro-
duced what explanation can you give ?

EXPERIMENT LXIIL*

Atropine. (Dog, Cat or Rabbit: Blood-pressure, Respira-
tion, Heart and Vagus Nerve, Dog, Salivary Secre-
tion and Chorda Tympani, Sweat Nerves,
Pancreatic Secretion.)

1. Anesthetize a dog, cat (two grains urethane by stom-
ach) or rabbit (two grams urethane by stomach) and ar-
range for recording blood-pressure and respiration. Iso-
late and ligate loosely both vagus nerves. The injecting
burettes contain atropine (one cubic centimeter equals one-
half milligram) and adrenaline (1:10,000).

// a dog is used dissect out AVharton's duct and place a
cannula in it (Figs. 237, 238, 239, and 240). Also isolate
the chorda tympani nerve and stimulate it once or twice to
observe the normal rate of salivary secretion. Some opera-
tors tie a ligature on the chorda and cut the nerve centrally
to the ligature. In this manner the ligature can be used to
lift the nerve as desired. Generally it will be sufficient
to stimulate the nerve in position without ligating it. (The
dissection mav be tried on a cat or rabbit if the instructor

so advises.)

Stimulate the vagi and obtain normal records of the ef-
fects on the heart, blood-pressure and respiration. Observe
the pupils (on the same side) as each vagus nerve is
stimulated.

If time permits, the student may dissect out the sciatic
nerve (in dog) and stimulate it to observe the secretion of
sweat on the sole of the foot. To do this take a piece of
wet cotton and wash the pads of the foot off well, then dry

*If more than one group performs this experiment, the second group may use scopo-
lamine one cubic centimeter equals one milligram instead of atropine.

ACTION OF ATROPINE

them and place the foot in such a manner that a good light
can fall at a slight angle on to the pads. A hand lens may
be used to considerable advantage. Stimulate the corre-
sponding sciatic nerve and watch for minute droplets of
sweat to form on the pads. On that side of the animal it is
advisable not to place a cannula in the femoral vein but in-
sert the cannula in the external jugular vein instead. Do
not injure the circulation in isolating the sciatic nerve.

Arrange all writing points on the drum (medium speed)
and while taking a normal (satisfactory) record begin to
stimulate one vagus nerve with a weak or medium strength
of current (tetanizing). The current should be of just great
enough strength to slow the heart markedly but not to com-
pletely stop it. Do not continue this any longer than neces-
sary or the vagus endings may be worn out. While thus
holding the heart down to a slow rate by a constant stimula-
tion (increase the strength of the current if necessary) of
the nerve inject two cubic centimeters of atropine solution
(for a dog, if a cat or rabbit is used inject one-half or one
cubic centimeter of atropine solution).

Continue the stimulation. Do you observe any change
after the drug has had time to be carried to the heart in
the blood? (Remember the circulation is slow and sluggish
when the heart beats but slowly and the pressure is low).
How do you explain your findings? Now inject another
dose of atropine as soon as the animal can tolerate it. Then
stimulate the opposite vagus nerve and note the effect on
the heart rate and blood-pressure. Stimulate the chorda
tympani and note the effect on salivary secretion. How do
you explain this?

Examine the sole of the foot (dog) carefully for sweat
droplets (remove these if any are present) and then stimu-
late the sciatic again. What conclusions can you draw?
Were you able to get a sweat secretion by stimulation of the
sciatic before the drug was injected? If not what does this
part of the experiment show? Again stimulate one vagus

272 EXPERIMENTAL PHARMACOLOGY

and watch the effect on the (corresponding) pupil. What
changes, if any, do you note ? How do you explain these f

What effect has atropine in small doses on the blood-
pressure and respiration? A poisonous drug suddenly in-
jected into the circulation often gives a fall of pressure due,
according to some authorities, to irritation of the heart.
Do you believe this explanation is sufficient to account for
such changes? The vasomotor centers and the vessels, etc.,
may also be specifically involved. What action has atropine
on the vasomotor apparatus?

If the experiment is performed on a cat or rabbit kill the
animal with a large dose of the drug and secure a death
record. If a dog is used inject a little adrenaline and ob-
serve the action of this on the pupil (explain). Open the
abdomen and insert a cannula (Figs. 244 and 245) into the
pancreatic duct. Inject twenty cubic centimeters of A%
hydrochloric acid into the duodenum with a large hypo-
dermic syringe and wait ten or twenty minutes to see if
there is any secretion of pancreatic juice. How is the secre-
tion of the pancreas controlled? What action has atropine
on this mechanism? What effect will stimulation of the
vagus nerves now have on the pancreas? Try this (use
slowly repeated single shocks). Inject some adrenaline and
see if this affects the secretion.

Kill the animal with a large dose of atropine, securing a
death record of the blood-pressure and respiration. What
is the immediate cause of death?

2. If time permits after the animal is dead, consult Fig.
281 and dissect out the optic nerve at the posterior side of
the eye ball. Be careful not to injure the blood vessels.
With scissors cut the skin and fascia outwards (backwards)
from the outer canthus of the eye. Then seize the fascia
over the back of the eye ball with forceps and roll the ball
forward (inward). A mass of orbital fat and fascia will be
seen behind the eye. Carefully dissect this away and watch
for the optic nerve which is about three millimeters in di-

SCOPOLAMINE, PILOCARPINE, ATROPINE 273

ameter as it enters tlie eye ball. Place the tips of the elec-
trodes on the nerve and carefully work the points into the
substance of the nerve trunk. "Watch the pupil closely and
stimulate. Is there any action? Perhaps the animal has
been dead too long. Do you think of any other reason?
Master the technic of the operation for you will want to
repeat it later. What is the innervation of the iris?
How do these nerves get into the eye? Can you reach them
in the way you have proceeded here? What are mydri-
atics? Myotics? Cycloplegiacs ?

EXPERIMENT LXIV.
Scopolamine. (Frog: General Symptoms.)

1. Into the anterior lymph sac of a frog inject one
cubic centimeter of scopolamine (one cubic centimeter
equals five milligrams). Put the animal in a quiet place
and observe the symptoms produced. "What conclusions
can you draw? Examine the pupils from time to time and
note the action on the lymph heart beats. Give a larger
dose if necessary to bring on marked symptoms.

EXPERIMENT LXV.
Pilocarpine, Atropine. (Frog: Heart and Vagus Nerve.)

1. Pith a frog, take a normal heart tracing showing-
vagus and crescent inhibition and then while the drum is
running at a fairly slow speed begin to drop on to the heart
pilocarpine (nitrate or hydrochlorate) solution (one cubic
centimeter equals one milligram). Watch for a slowing
of the beat. The heart may be entirely stopped. How do
you account for this? When the slowing has become very
marked pour about three or four drops of atropine solu-
tion (one cubic centimeter equals one milligram) on to the

274

EXPERIMENTAL PHARMACOLOGY

heart and note the effect on the heart rate. How do vou

*/

explain this? Stimulate the vagus and crescent again.

2. Cut out both eyes and place one in a normal salt solu-
tion, the other in salt solution containing pilocarpine (one
cubic centimeter equals five milligrams). Place the eyes
aside for ten or twenty minutes and examine the pupils
again. Can you detect any pupillary changes? What ex-
planation can you offer?

Fig. 241. Lung tracing from a turtle showing the action of pilocarpine.

EXPERIMENT LXVL

Pilocarpine or Arecoline and Atropine. (Frog:

Circulation.)

Retinal

1. Arrange a frog as shown in Fig. 164 and examine its
retinal blood vessels with an ophthalmoscope. Find one or
two very small vessels, preferably showing a branching so
that the individual corpuscles can be seen moving into each
division. Get a good notion of the rate of this movement
for later comparison.

Under the skin of the back inject two cubic centimeters
of pilocarpine solution (one cubic centimeter equals two
milligrams) or arecoline hydrobromide (one cubic centi-
meter equals one milligram, Merck and Co.) solution.

auricular
nerve

timpani
^superficial
Temporal art.

Chordo-
'ngual
nerve

Sub lingual
9/and
^Su/) maxillary

gong
ttiefic

Descending
sympathetic fibres
in spinal cord

Cervical sympathet

Fig. 242. Schematic representation of the general plan of distribution of the nerves

from the medullary centers to the salivary glands. This distribution is typical for a

considerable number of other structures, glands, muscles, etc., located in the head.
(1'artially adopted from Eycleshymcr and Schoemaker.)

Facial artery

Mylo-hyoid. branch of fifth nerve I /Sympathetic fibres accompanying

Facial artery

Chorda tytnpani

Submaxillary
gland

iDuctof submaxillary

Lingual nerve

Hypoqlossal 'nerve
\cut) ^~
Lingudl artery

Ext d;V. jp.
accessory
nerve
Hypoqlossal

nerve
Br. 1st. cervical

nerve

Sup.cervical
ganglion
Glosso-pharyn-
geai nerve

Ant. sympathetic
fibres going to

inter-carorid

p/exus

Vagus nerve

Com. carotid
artery

Fig. 243. Dissection of the submaxillary and sublingual glands and their ducts, certain
cranial nerves and arteries and of the cervical sympathetic trunk and the superior cervical
ganglion. (Modified from Claud Bernard.)

PILOCARPINE, ARECOLINE, ATROPINE 275

From moment to moment observe the eye ground and
watch for any change in the rate of capillary movement.
If yon succeed well in getting a change, then with a fine
pointed hypodermic syringe inject into the pericardium
one-half cubic centimeter of atropine solution (one cubic
centimeter equals one milligram). What changes do you
observe in the retinal circulation! How do you explain
this?

EXPERIMENT LXVII.

Pilocarpine or Arecoline and Atropine. (Dog, Cat, Rabbit,
and Pigeon or Chicken: Pupil.)

1. Into the right eye of as many of these animals as
may be available inject about twenty drops of pilocarpine
(one cubic centimeter equals five milligrams) or arecoline
(one cubic centimeter equals three milligrams) solution.
Open the lids and fill the conjunctional sac as completely
as possible and keep the solution in as long as you can.
Into the left eye of each animal drop atropine solution (one
cubic centimeter equals four milligrams). Leave the ani-
mals alone quietly and at intervals of a few minutes com-
pare the two eyes. Do you note any pupillary changes?
Explain these.

EXPERIMENT LXVIIL

Pilocarpine, Atropine. (Dog: Blood-pressure, Respiration,
Salivary and Pancreatic Secretions.)

1. Anesthetize a ten kilo dog (ether only) and arrange
to record blood-pressure and respiration. Insert a cannula
in Wharton's duct (Figs. 237, 238, 239 and 240) and dis-
sect out the chorda tympani. Stimulate it and get a nor-
mal secretion.

Open the abdomen and insert a cannula into the large

276

EXPERIMENTAL PHARMACOLOGY

pancreatic duct (Figs. 244 and 245). Stimulate the vagus
nerve with a series of single shocks repeated at frequent
intervals (does this stop the heart!) and see if you can get
a flow of pancreatic juice. Keep this up for five or ten
minutes if necessary.

Three injecting burettes should be used, one in each
femoral vein and one in the left external jugular vein.

Fig. 244. A dissection showing the position and relations of the pancreatic ducts
in a dog. /, intestine; O, omentum; M, mesentery; S, stomach; P, pancreas (tail); BD,
position of bile duct (dotted, beneath the pancreas) ; LD, large duct, and SD, small duct
of the pancreas. The pancreas is partly cut away to show the position of the ducts.

This latter one contains adrenaline, the other two contain
atropine (one cubic centimeter equals one milligram) and
pilocarpine (one cubic centimeter equals one milligram).
Observe the size of the pupils carefully. Then adjust all
writing points and take a short normal record. Inject one
cubic centimeter of pilocarpine solution. What is the ac-

ACTION OF PILOCARPINE AND ATROPINE 277

tion of this drug on the heart and circulation? Is there
any action on the glands? Be sure no atropine gets into
the vein until you are entirely ready for it.

When the animal recovers inject more pilocarpine. Be
sure you get in enough to bring out the action of the drug
well. The animal is not likely to die early if small doses
are used. Note the action on the pupils, salivary glands
and pancreas. How do you explain this? Inject one-half
cubic centimeter of adrenaline and see how this counter-
acts the action of the pilocarpine. Examine the pads of the
feet and see if any small sweat drops are forming. (Ke-
member the circulatory disturbance you have caused in the
hind limbs.) Inject more pilocarpine and try to get as
marked action on the heart as possible. In a good typical
case a long series of carotid tracings may be obtained in
which separate heart beats may have an amplitude of from
one-half up to three-fourths of an inch. When this stage
is reached quickly observe the rate of salivary and pan-
creatic secretion and then inject one cubic centimeter of
atropine. This will not reach the heart for some time.
Wait and see what happens. Explain all results observed.
On what structures does each drug act? If necessary in-
ject one cubic centimeter more of atropine. Now inject
one-half cubic centimeter of adrenaline to restore the ani-
mal. Stimulate the chorda tympani and the vagi. What
effect has this on the salivary or pancreatic secretion?
How does the vagus stimulation affect the heart, blood-
pressure, and respiration?

Observe carefully your record of respiration just after
the pilocarpine was first injected. Is there a peculiar de-
crease in amplitude with some difficulty in either expira-
tion or inspiration? "What possible explanation can you
offer for this? How did the atropine affect it?

Inject one cubic centimeter more of pilocarpine. Is the
heart slowed? On what structures does atropine antago-
nize the action of pilocarpine? What is the action of pilo-

278 EXPERIMENTAL PHARMACOLOGY

carpine on the adrenal glands? (Dale and Laidlaw: Jour-
nal of Physiology, 1912.)

Kill the animal with a large dose of pilocarpine and ob-
tain a death record. Watch the pupils as the drug is in-
jected. What do you observe? What is the immediate
cause of death?

If time permits open the chest and fit into it a piece of
apparatus like that shown in Fig. 255 (or Fig. 256, if you
happen to have this). Close the chest with hemostats as
shown in Fig. 257. Could you do this in a living animal?
Remove and wash all your apparatus.

EXPERIMENT LXIX.

Pilocarpine, Arecoline, Adrenaline, Atropine, and Barium.
(Dog: Bladder, Intestine, Respiration, Blood-pressure.)

1. Etherize a dog and arrange to record blood-pressure
and respiration. Open the abdomen and connect a mercury
bulb to the bladder in the manner shown in Figs. 179 and
199 and arrange to record bladder contractions on the
tipper part of the drum (the tambour pointer will rise
when the bladder contracts allow space for this.)

Observe the apparatus shown in Fig. 246 for recording
intestinal contractions. Arrange a burette, catheter and
finger cot (or rubber glove finger) as shown and make a
small longitudinal incision in a loop of the small intestine.
Slip the end of the catheter over which the finger cot is at-
tached about four or five inches down the lumen of the in-
testine from the incision. (The tip of the catheter reaches
entirely to the end of the finger cot and thus forces the cot
along.) Fill the burette half full of water and move the
catheter in and out a little to be sure the finger cot is filled
iritli water and that the air is expelled. Stitch together
the incision in the intestine around the catheter and close
abdomen with hemostats. The intestinal tambour should

Fig. 245. Dissection showing the position and relations and the method of isolating the large
duct of the pancreas in a dog. The method for inserting a cannula into the duct where it lies
within the wall of the intestine is also shown.

RECORDING INTESTINAL CONTRACTIONS

279

write just below the bladder (the pointers must be able to
pass each other), below this are the blood-pressure, respi-
ration and base line. The injecting burettes contain pilo-

Elashc rubber
band fo attach
finqer cot'
'cdftte/er

Fig. 246. Arrangement of apparatus for recording contractions of the intestine. (For

discussion see text.)

carpine (one cubic centimeter equals one milligram) and
adrenaline.

Take two inches (or less) of normal record and then in-
ject one cubic centimeter of pilocarpine. A pronounced re-
sult should be obtained in all the tracings. Do you get

280

EXPERIMENTAL PHARMACOLOGY

this? Wait for the action of the drug to become well de-
veloped. If you are sure the dose was too small then inject
a second (but one cubic centimeter is usually sufficient for

Fig. 247. Tracing showing the action of barium, adrenaline and atropine on the
blood-pressure and intestinal contractions in a dog. The barium had been given just
before this tracing begins. Its action on the intestine is quite evident but the contrac-
tions are checked, first by adrenaline (which stimulates the inhibitory endings) and.
second by atropine. How do you explain this latter action?

BARIUM, ADRENALINE, PILOCARPINE

281

average sized dogs). When the effects are well marked
inject one-half cubic centimeter of adrenaline. What pilo-
carpine reactions does this counteract? Your records
should show marked results.

Fig. 248. Tracing showing the comparative extent of duration of the action of barium
and of adrenaline on intestinal contractions and on the blood-pressure in a dog.

Allow the animal to return to normal and then repeat
the pilocarpine and adrenaline injections.

Allow the animal to recover for a few minutes and mean-
while empty the pilocarpine out of the burette and replace

Fig. 249. Tracing showing the action of arecoline and of atropine on intrathoracic
pressure, bladder contractions and blood-pressure in a dog. Intrathoracic pressure was
recorded by means of a tambour with a moderate! v tightly stretched rubber membrane.
The tambour was connected with a glass tube which was passed into the chest cavity
(without letting air in:o the chest). Arecoline strongly contracts the bronchioles and
thus shrinks the volume of the lungs. This drew air out of the tambour into the chest
and caused the writing point to write at a lower level. The bladder and heart both show
a marked reaction to the drug. These effects are partially counteracted by the atropine.

Sympathetic chain

Pudic nerve fibers
(Motor, 3 bo vaso-constrictor^

Corpus cavernosum

-5pinal
cord

nerves

Pelvic
ganglia

Retractor penis muscle*
'Corpus spongiosum

Urethra Pelvic(Erigens)nerve fibers

(Inhibitory, also vdSO-dilator)
(Erection)

Fig. 250. Schematic representation of the innervation of the retractor jienis muscle.
The vasomotor innervation for the region is also indicated.

ARECOLINE AND ADRENALINE

283

it with arecoline solution (one cubic centimeter equals one-
half milligram).

Adjust all writing pointers and take a normal record.
Inject one cubic centimeter of arecoline. This will give pro-

Fig. 251. Tracing showing the action of pilocarpine on the rate of ovygen consumption,
intestinal contractions, blood-pressure and respiration.

found results. Wait for the drug to act and when the
symptoms are very marked inject adrenaline (probably
three-fourths cubic centimeter). Wait for the animal to

284

EXPERIMENTAL PHARMACOLOGY

recover as much as possible. Give a second dose of adren-
aline if necessary. Then empty out the adrenaline (be
sure the bull-dog on the vein does not leak) and fill this
burette with twenty cubic centimeters of atropine solution
(one cubic centimeter equals one milligram.)

Fig. 252. Tracing showing the action of a fatal dose of barium chloride on uterine con-
tractions, blood-pressure and respiration.

Get the animal into as good condition as possible and
then inject one cubic centimeter (or one and one-half cubic
centimeters) of arecoline. Wait for the action of the drug to
become well developed and then inject one cubic centimeter
of atropine. Wait for this to be carried to the heart. What

ADRENALINE AND BARIUM

285

Fig. 253. Tracing showing the action of adrenaline and barium chloride (after atropine)
on the heart (myocardiogram.) and blood-pressure.

286

EXPERIMENTAL PHARMACOLOGY

Fig. 254. Tracing showing the action of a fatal dose of barium chloride on the
heart (myocardiogram, right auricle and left ventricle) and blood-pressure in a dog.
Note that the auricle continues to beat long after the ventricle has stopped.

PILOCARPINE, ADRENALINE; ARECOLINE, ETC. 287

do you observe? How do you account for it? Pilocarpine
acts very much like arecoline (as does also muscarine) but
arecoline is much more powerful.

Does atropine counteract all the actions of pilocarpine
or arecoline? Do your records show this? Inject one-half
cubic centimeter more of atropine. Then empty the atro-
pine out of the burette and replace it with barium chloride
solution (one-half per cent). Arrange all writing points
and inject one cubic centimeter of arecoline to see if it acts
as it previously did. Empty out the arecoline and replace
it with adrenaline. If the dog weighs ten kilos or more
then inject five cubic centimeters of the barium solution (a
smaller dose for a smaller dog). It will take about one-
half minute for the action of the drug to become well
marked (if the animal was in fair condition when the drug
was injected). The reaction should be very marked.
When this occurs inject one and one-half cubic centimeters
of adrenaline. Does this counteract any of the actions of
barium? On what structures does barium act? Did the
previous administration of atropine affect this in any way ?
Kill the animal with a big dose of barium and just after
the death record is made quickly open the chest (with large
tinner's snips) and observe the heart action. What is delir-
ium cordis? What is fibrillation?

EXPEEIMENT LXX.*

Pilocarpine, Adrenaline, Arecoline, Atropine, Barium.
(Spinal Dog: Blood-pressure and Bronchioles.)

1. Etherize a dog (ten kilos) and arrange for blood-
pressure records. Place injecting burettes in both femoral
veins and one in the left external jugular. These burettes
contain adrenaline (1:10,000), pilocarpine (one cubic cen-
timeter equals one milligram) and arecoline (one cubic

*Cats may be used for this experiment, but dogs are greatly to be preferred.

288

EXPERIMENTAL PHARMACOLOGY

centimeter equals one-half milligram). (Muscarine one
cubic centimeter equals one milligram may be substituted
for one of the last two drugs or be used separately if it
is available.)

Observe carefully the apparatus shown in Fig. 255.

Inlet

Derail /o snow anqle
of wire brace.

^

i ^- x A* jf

.'^.'&*' '- -'Mi Fl3T1 ^ ~fJ

-.j^ ^a wed ed^e

' ^y'^/

of sternum

Diaphragmatic

surface

Fig. 255. A form of apparatus (approximately one-half natural size) made of sheet
brass to place in the chest to hold the walls rigidly wide open and air tight while the
records of changes in the caliber of the bronchioles are taken. A dotted circle in the
center of the curved plate shows where a window may be placed to great advantage if
sufficient shop facilities are available to do this. The window may be made of a sheet
of celluloid (such as is used in automobile curtains) or of glass, and if the window is
removable this also adds to its usefulness. The curved wire at the base is made of 3/16
inch brass rod. Any tinner should easily be able to make up at a very small cost such a
piece of apparatus, which can be made of "tin" (tinned iron) or galvanized sheet iron.
The instrument may be used for recording bronchial contractions by use of either posi-
tive or negative artificial respiration, but the latter (aspiration of the chest) is greatly
to be preferred. (For the method of use see text.)

RECORDING BRONCHIAL CHANGES

L'S<)

This apparatus works best when the air is intermittently
aspirated out of the chest (25 or 30 times per minute-
45 millimeters of mercury negative pressure with the by-
pass or inlet adjusted to give proper strength of suction
to fill the lungs well). In the absence of a machine capable
of giving negative interrupted pressure (see Fig. 360) pos-
itive artificial respiration may lie used in the ordinary
manner by blowing air into the trachea. Even a hand bel-
lows may be used for this, but a power driven machine is

G/asi window

'jjjj; -Removable cap

Tube for
/ aspiration

Adjustable by-pass

Diaphraqmotic
Surface

Notch, for
ner/cardia/ sac

Flanqe for sternum
Costal surface

,:i

Fig. 256. Another form of apparatus for insertion into the chest to record bronchial
changes. About one-third natural size. The three wings at the bottom are placed inside
the chest and are adjustable (by the thumb nuts) to fit various sized chests. When the
can (with a glass or celluloid window) is removed, the hand may be passed into the
chest to massage the heart, etc. The movements and changes in the lungs and heart
can be seen through the window. (For the method of use see text.)

greatly to be preferred. The apparatus shown in Fig. 256
may also be used for the lungs.

The chest of the animal is now opened by a median lon-
gitudinal incision, the apparatus is inserted as shown in
Fig. 257 and the edges are clamped around air tight with
liemostats. It is often advisable to sew one or two stitches
of heavy twine from side to side through the skin of the
upper end of the chest. The flange of the apparatus
catches the sawed edges of the sternum on each side and

290

EXPERIMENTAL PHARMACOLOGY

thus holds the chest open. As soon as the chest is opened
artificial (positive) respiration is begun. Two forms of
apparatus for thus giving ether to an animal are shown in
Figs. 53 and 107. The artificial respiration thus begun
is kept up throughout the experiment if only positive pres-
sure is available. But if negative (interrupted) pressure
is available this is substituted immediately after tlie ani-
mal is pitlied.

If positive pressure is used then the closed chest acts as

^-Adjustable by-pass

Fig. 257. Adjustment of the apparatus shown in Fig. 255 in the chest of a dog.
The sawed edge of the sternum catches against the flange of the apparatus and the skin
and fascia are brought up and clamped tightly with hemostats to the edges of the plate.
One or two stitches may be taken to draw the chest together at the front end of the
?nparatus. If '-nsi ; ve artificial respiration is used this apparatus simply converts the
chest into a rigid-walled plethysmograph or oncometer for the lungs and heart. A glass
(or celluloid) window aids greatly by allowing the operator to see when the lungs are
being sufficiently inflated.

an oncometer and the tube to the recording tambour (which
should have a large bowl) is connected to the tube labeled
"aspirate' 1 in Fig. 255. Thus when the lungs are blown
full of air through the trachea and are thus expanded air
will be forced out of the chest and into the tambour the
pointer of which will rise. Conversely when the lungs col-

PRELIMINARY OPERATIONS 291

lapse air will be drawn into the chest from the tambour
and the pointer will descend. If the bronchial muscles
contract or dilate the extent of this movement will be cor-
respondingly decreased or increased. The extent of ex-
pansion or contraction of the lungs can be controlled by
the screw clamp on the tracheal cannula (if the volume of
air delivered by the respiration machine at each inflation
cannot be independently controlled). The extent of move-
ment of the tambour pointer, i. e., of the amount of air en-
tering or leaving the tambour bowl, can be controlled by
the screw clamp on the ' ' inlet ' ' of Fig. 255.

If negative pressure is used this is applied only after the
dog is pithed (this being determined by the administration
of the ether which is better done by positive artificial respi-
ration). Figure 257 shows the way to arrange the tubes to
the apparatus. In this case the tube to the recording tam-
bour is attached to the side tube (or better the end) of the
tracheal cannula (the ether bottle is removed, for it is no
longer necessary as the animal will then be pithed). The
other opening of the tracheal cannula carries a piece of
rubber tubing and a screw clamp. This clamp is used to
regulate the facility with A\ r liich air passes into and out of
the trachea and lungs. This regulates the size of the tam-
bour stroke on the drum. Closing the clamp down in-
creases the amplitude of the tambour stroke; opening the
clamp decreases the stroke. The attachment of the tam-
bour here and the removal of the ether bottle can be done
only after the animal is pithed.

When the apparatus is adjusted pith the animal. To do
this consult Figs. 258, 259, 260, 261, and 262.

Unfasten the dog's head and turn it on the left side.
The anesthetist watches carefully to see that the chest or
trachea is not compressed and that the animal gets suf-
ficient air while this part of the operation is performed.
With a scalpel make a median incision over the skull and
with large tin snips cut the skin away in a V-shaped area

292

EXPERIMENTAL PHARMACOLOGY

(Fig. 258). With a scalpel cut close to the bone and dis-
sect loose the right temporal muscle. Reflect this upward
and hold it up with forceps. Take a trephine instrument

Fig. 258. Method of making the first incision before trephining the skull. The
longitudinal (mesial) edge of the opening is cut with a scalpel. The triangular piece
of skin and fascia is then lifted with forceps and cut awajj with heavy (6 inch) tinner's
snips.

Fig. 259. The trephine opening is made about one-half to three-fourths of an inch
outward from the median line to avoid the great longitudinal sinus.

(Fig. 100) and make an opening in the skull (Fig. 259).
Be careful to aroid the lout/it x.dinal xhtu* tlie opening
should be one-It alf to three-fourths of an inch away from

PITHING THE ANIMAL

293

the median line. Place a wad of cotton in the forceps and
hold this in the left hand ready to cover the trephine open-
Pass a long narrow scalpel blade into the opening

ing.

Fig. 60. Method of quickly cutting across the brain stem with a long narrow
bladed scalpel while a wad of cotton is held in the forceps ready to crowd into the
trephine opening to check all loss of blood

Fig. 261. The cotton is held down firmly in the trephine opening while a probe is
slipped in past the cotton and is moved quickly and thoroughly about in a circular
manner to destroy every part of the brain. If the cord is also to be destroyed this is
done_by passing a long fairly flexible wire (one-eighth inch soft brass rod) through the
trephine opening and out through the foramen magnum into the spinal canal. The head
and neck may be moved a little to assist in passing the rod down the spinal canal to
destroy the cord.

and cut quickly across the brain stem. Remove the scalpel
and close the opening with the cotton. No blood should
escape. Into the upper end of the opening beside the cot-

294

EXPERIMENTAL PHARMACOLOGY

ton pass a probe (Fig. 261) and with a circular motion de-
stroy every part of the brain. Keep the cotton plugged
tightly in the opening. If it is desired to destroy the cord
a one-eighth inch soft brass wire slightly curved at the
end may l3e inserted past the cotton and forced through
the foramen magnum and down the spinal canal. Bend
the animal's neck and head a little to assist in getting the
rod to enter the canal easily. Remove the rod, plug the
opening tightly with cotton, and replace the animal's head
into its original position. Remove the ether quickly, the
animal will lie perfectly still and the blood-pressure will

Fig. 262. After the brain (and cord, if desired) is destroyed the trephine opening
is plugged tightly with a wad of cotton forced in by the hooked end of an aneurism
needle. The animal's head is then quickly returned to the usual position.

fall to a height of about three-fourths to one inch above
the base line as seen on the drum.

If negative pressure is used change to this now. If pos-
itive pressure is used attach the tambour and adjust all
writing points on a slow drum, lung tracing at the top,
below this the blood-pressure, and then the base line and
time signal. The lung tracing should have an amplitude of
about three inches. Be sure the manometer pointer will
pass up just to the right of the tambour pointer.

Take one-half or one inch of normal record. Inject one
cubic centimeter of pilocarpine. Wait a little for the ef-
fect to develop ivell. Then inject one-half cubic centime-

PILOCARPIXE, ATROPIXE, MUSCARIXE, ETC.

295

o cr. T3 n

o q- --PJ
s 2 %~Z-

- 1 C- TO

o o

2 S'o-

s.S 3
3-15

w

--

re u o

re 3 ^

o o . ""
C o a

='2 "2.

"

296

EXPERIMENTAL PHARMACOLOGY

ter of adrenaline. Wait the blood circulates slowly.
What do yon observe ? How do yon explain it ? What
mechanical factors are concerned? A second contraction

Fig. 264. Tracing shewing the action of local (Burrough . V," llcome and Co.) on
the blood-pressure and bronchioles in a spinal dog. The animal had received a dose of
pilocarpine a little while before this tracing begins and the bronchioles were partially
contracted (tonus) from the action of the pilocarpine which exercises a prolonged effect
on the broncho-constrictor nerve endings.

of the bronchioles will likely come on as the effect of the
adrenaline passes off. Wait for this and give a second in-
jection of adrenaline. (If the first dose of pilocarpine was

ARECOLINE, ADRENALINE, ATROPINE, ETC. 297

too small this is seldom the case then a second may be
given but this reduces the vitality of the animal markedly
and is best avoided.)

Get the animal into as good condition as possible and
(take a normal) inject one cubic centimeter (less if tin*
animal is small) of arecoline solution. The response will
probably be profound. Wait for the heart to beat slowly
again. When the bronchioles are greatly constricted in-
ject one cubic centimeter of adrenaline. \> f 'aii lor the drug-
to be carried around. The result should be striking. How
do you explain this ? (If the first dose of arecoline was too
small this is seldom the case then a second may be given
but this is best avoided.)

Empty out the pilocarpine (be sure the bull-dog on the
rein does not leak) and fill the burette with atropine solu-
tion (one cubic centimeter equals one milligram).

Take a normal record and inject one cubic centimeter
(or one and one-fourth cubic centimeters) of arecoline.
When the action is marked inject one cubic centimeter of
atropine. Wait for the drug to circulate. What do you
observe? Explain all mechanical factors. Inject one-half
cubic centimeter of arecoline. What conclusions can you
draw?

Empty out the areeoline and fill the burette with one-
half per cent barium chloride solution. Barium acts pre-
sumably directly on the smooth muscle fibers. Remember
the animal has Itad atropine. Take a normal record (the
animal will probably be greatly weakened by this time)
and inject five cubic centimeters of barium solution (three
cubic centimeters if the animal is small). What do you
observe? It will take some time for the action to become
marked. Is the heart irregular? Barium acts somewhat
like digitalis and in some respects resembles adrenaline.
Do the bronchioles contract? If so inject two cubic centi-
meters of adrenaline. Do they respond to this? Kill the
animal with a bie; dose of barium. How does barium act on

298

EXPERIMENTAL PHARMACOLOGY

Fig. 265. Tracing showing the action of arecoline on the rate of oxygen consump-
tion (and the broncho-constriction), intestinal contraction, blood-pressure and respira-
tion in a spinal dog.

ARECOLTKE A1STD ATROPINE

299

Fig. 266. Tracing showing the action of arecoline and atropine on the heart
(myocardiographic record, right auricle and left ventricle) and blood-pressure in a dog.

300 EXPERIMENTAL PHARMACOLOGY

the heart ? Discuss in full the action of pilocarpine, areco-
line (muscarine), atropine, adrenaline and barium on the
bronchioles. What part do the medullary centers play in
this action? AYhat is the innervation of the bronchioles?
(See Dixon and Ransom: Journal of Physiology, 1914.)

EXPERIMENT LXXI.
Nicotine. (Frog: General Symptoms.)

1. Into the anterior lymph sac of a frog inject one-half
cubic centimeter of one-half per cent nicotine solution.
Place the animal in a sink and watch its actions. Do you
observe anything peculiar about its attitude I When the
dose is too large the animal may die too quickly to show
typical effects. Make a sketch of the position of the limbs
after the action of the drug becomes marked. "\Vatch and
see if this stage passes off. Save the frog and observe it
as often as possible for several hours. Do you note any
convulsions at any time! On what structures does nicotine
act to produce these results!

EXPERIMENT LXXIL

Nicotine. (Frog: Heart and Vagus Nerve.)

1. Pith the frog and take a normal heart record show-
ing both vagus (trunk) and crescent inhibition. Pour two
drops of nicotine solution (one per cent) on to the heart.
AVait a few seconds. Do you get an immediate effect?
How do you explain this ? If there is a change in the
heart rhythm does this continue or is there a return to
normal! Stimulate the vagus and note the effect on the
inhibition of the heart. How do you explain this ? Stimu-
late the crescent. Explain your results. How does nico-
tine cause these two results? Is the heart muscle directlv

ACTION OF XICOTTXE

301

affected? Apply more of the drug and observe the later
action on the heart. What is the innervation of the heart
(Fi-. 222) 1

Fig. 267. Prop heart tracing showing the action of nicotine. The vagus trunk
was stimulated as indicated. In the normal (lower) tracing inhibition occurs but after
nicotine (second tracing) no inhibition follows. How do you explain this? Stimulation
of the crescent in the next two lines still is followed by inhibition. The final effects
of the drug are shown in the last two (upper) tracings.

EXPERIMENT LXXIII.
Nicotine. (Turtle: Heart and Vagus Nerve.)

1. Eepeat the above experiment on a turtle which is a
more satisfactory animal for the experiment than is the
frog. Why ?

302 EXPERIMENTAL PHARMACOLOGY

EXPERIMENT LXXIV.
Nicotine. (Turtle: Lungs.)

1. Pith a turtle, brain and cord. Remove the plastron
as shown in Fig. 232. Consult also Fig. 233. Arrange a
eannula in the wind pipe and a small (very sensitive)
tambour to write on the drum. The magnification for the
writing point should be large. Partially inflate the
lungs (blow them up from the air vent in the tambour
tube) and adjust the tambour on the drum. (A heart
tracing may be taken also when the nerves are stimulated,
but it is difficult to get a satisfactory heart tracing when
drugs are injected into the heart. It is possible to inject
drugs into the large vein running into the liver but this re-
quires considerable care and when lung records only are
w r anted the heart is best left alone.)

Dissect out the vagus and sympathetic nerves on one
side of the neck and stimulate them. Do you get a satisfac-
tory record? Go far down in the tissues at the side of the
neck and find the sympathetic branch which joins a gan-
glion on the vago-sympathetic nerves. Stimulate this
branch and see if you can get a lung tracing from it. (The
opposite lung may be temporarily shut off by a bull-dog
on the corresponding bronchus.)

After one or two records of the lung contraction follow-
ing nerve stimulation have been secured then remove the
bull-dog from the bronchus, see that both lungs are mod-
erately distended and that the tambour is properly ad-
justed on the drum. Start the drum and with a fine-pointed
hypodermic syringe inject into the ventricle one or two
cubic centimeters of one-half per cent nicotine solution.
The circulation is sluggish in the turtle and some time may
elapse before the drug reaches the lungs. Wait for the
effect to come on. Be sure the turtle is in a satisfactory
condition (not diseased or weakened in any way) and that

ACTION OF NICOTINE

303

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304 EXPERIMENTAL PHARMACOLOGY

the heart beats well. A marked effect should be produced.
Explain the action of the drug in this case. It will be in-
structive if you can compare the action of nicotine on the
turtle lung with the corresponding action on a dog's lung.

EXPERIMENT LXXV.

Nicotine, Arecoline, Atropine. (Dog: Blood-pressure, Res-
piration, Limb Volume, Intestinal Contraction.)

1. Etherize a dog and arrange for blood-pressure, res-
piration and intestinal contraction (Fig. 24(i). Examine a
plethysmograph for the hind limb of a dog (Fig. 269).
Rub soapsuds around the left hind leg close up to the
body of the animal. Take a razor and shave the hair all

Fig. 269. Method of application of a plethysmograph to the hind leg of a dog.

off ill band about one and one-half inches wide entirely
around the leg. (A strong solution of sodium sulphide
may be used to remove the hair by rubbing the solution
over the selected area. The hair can then be readily scraped
off. But this is a filthy method. A cheap safety razor is
best.) The hair must be removed or the rubber band of
the plethysmograph will leak air around the limb. Attach
the plethysmograph as illustrated and connect it to a small
howled very sensitive tambour. From above down, the
records on the drum should be leg volume, intestine,
blood-pressure, respiration, base line and time signal. In-
jecting burettes should be placed in the right femoral and
the left jugular veins. These contain nicotine (one-half
per cent) and adrenaline.

ACTION OF NICOTINE

305

Take a normal tracing (stimulate the vagi and get the
cardiac effect) and then inject one cubic centimeter (less
if the animal is small) of nicotine solution. Watch the pu-
pil as the drug is injected. What do you observe? Wait

Fig. 270. Tracing showing the action of a fatal dose of nicotine on the blood-
pressure and respiration of a dog anesthetized with nitrous oxide. Can you see the
evidence of a preliminary stimulation (followed by paralysis) of the cardie-inhibitory
ganglia?

for the effects to pass off. What do your records show
for the intestine and leg? How can you explain these?
Inject one-half cubic centimeter of adrenaline. How does
this drug compare with nicotine in action? On what struc-

306 EXPERIMENTAL PHARMACOLOGY

tares does nicotine act and what is the nature of this ac-
tion? Do your records show this? Inject another dose of
nicotine of such size as your animal will probably tolerate
well.

Stimulate the vagus nerve and see how this affects the
heart. Do you get an inhibition! If so give another dose
of nicotine and again stimulate the vagus. What are your
conclusions! How could you prove this? Observe one pu-
pil and stimulate the corresponding vago-sympathetic
trunk. Does the pupil contract or dilate! How do you ex-
plain this ! What is the action of nicotine on the pupil ?

Empty the nicotine out of the burette and place arecoline
solution (one cubic centimeter equals one-half milligram)
therein. Inject one cubic centimeter of arecoline (less if
the animal is small) and get a record. Observe the pupil
as the drug is run in. Has the nicotine affected the action
of this drug in any way? Wait for the drug to act. Inject
one-half cubic centimeter of adrenaline to revive the ani-
mal (give a second dose if necessary.)

Empty out the adrenaline and fill the burette with atro-
pine solution (one cubic centimeter equals one milligram).
Take a normal record and then inject one cubic centimeter
(or one and one-half cubic centimeters) of arecoline.
When the action is very marked inject one cubic centimeter
of atropine. Wait the circulation is slow. Do you get
the proper response to the drug ? How do you explain this 1
Inject one-half cubic centimeter more of atropine.

Empty out the arecoline and fill the burette with nicotine.
Start the drum and inject one cubic centimeter of nico-
tine. Does your record correspond with the theoretical
action of the drug ? How do you explain this 1 What struc-
tures are involved? Kill the animal with a large dose of
nicotine. Discuss in full the counteraction of these drugs.
Open the chest, dissect out the left pulmonary artery and
place a ligature under it. (See Figs. 274, 275, 276, and
277.) Slip this ligature as far out on the artery as possible

NICOTINE, ADRENALINE, PILOCARPINE 307

and tie. Lift the ends of the ligature up and draw the lung
upward into view. Clamp the ends of the ligature to the
chest wall. Could you put a cannula into the artery (as
shown in the illustrations) while the heart was beating and
disturbing your operations considerably?

EXPERIMENT LXXVI.

Nicotine, Adrenaline, Pilocarpine, Atropine. (Dog: Blood-
pressure, Intraocular Pressure, Respiration and Kidney,
Spleen or Intestinal Loop Volume.)

1. Give a dog a small dose of ehloretone and then ether-
ize it. Arrange for blood-pressure, respiration and kidney,
spleen or intestinal loop volume records.

Observe the arrangement of the apparatus shown in Fig.
271. A medium sized syringe point is thrust into the an-
terior chamber of the eye as shown in the upper right hand
corner of the picture. The cornea is composed of tough,
dense tissue and the syringe point Avill not leak around the
outside if the needle is not moved from side to side after it
is inserted (at an acute angle) through the cornea. The
needle is attached to a rubber tube which connects with
a water manometer (filled with normal salt solution). The
needle and the end of the rubber tube are held in a hole in a
cork which is clamped in a burette clamp which can be
brought close to the eye. The manometer is filled with salt
solution from the mercury bulb and the tubes (washout
also) and needle are filled with the solution, a little of the
solution being allowed to run out of the needle as it is in-
serted through the cornea. It is advisable to use an extra
stand to hold the needle (burette clamp) close up to the
eye. The amount of pressure in the tube is regulated by
raising or lowering the manometer. The recording tam-
bour should be small. No fluid should be in the tube lead-
ing from the manometer to the tambour. The injecting

308

EXPERIMENTAL PHARMACOLOGY

burettes contain nicotine (one-half per cent) and adrena-
line. Stimulate the vagus nerve on the side on which the
eye record is being taken. What conclusions can you draw?
Bring all writing points on to the drum and take a nor-
mal record. Inject one cubic centimeter (twelve kilo dog.
less if tire animal is smaller) of nicotine and record the

Mercury bulb

or funnel - --

Antechamber

Syrinqe point
Perforai-ed cork

OpHc chiasma
Perforated cork I

Fig. 271. Arrangement of apparatus for recording intraocular pressure.

result. Stimulate the vagus nerve again and see what
happens. Explain. Inject one-half cubic centimeter of
adrenaline. Wait a sufficient time for the results to wear
off. What conclusions can you draw? What mechanical
factors are involved! Inject one cubic centimeter more of

ACTION OF NICOTINE

309

nicotine. How does this record compare with your first

one? What is the action of nicotine on the heart muscle?

Stimulate the vagi from time to time and note any change

in reaction. When an inhibition of the heart can no longer

Fig. 272. Tracing showing the action of nicotine on the spleen volume, blood-pres-
and respiration in a dog (etherized). Compare this record with one made by ad-

sure and respiration
renaline (or confine).

be obtained (inject more nicotine if necessary] then empty
out the nicotine and fill the burette with pilocarpine solu-
tion (one cubic centimeter equals one milligram).

Inject one cubic centimeter of pilocarpine. Wait for the

310 EXPERIMENTAL PHARMACOLOGY

drug to act. When the effects are well marked inject one-
half cubic centimeter of adrenaline. What conclusions can
you draw from your records!

Inject one-fourth cubic centimeter more of adrenaline (if
necessary) to get the animal into as good condition as pos-
sible. Then empty out the adrenaline (save it) and fill the
burette with atropine solution (one cubic centimeter equals
one milligram).

Inject another dose (estimate the size to get the results)
of pilocarpine and Avhen the reaction comes on inject one
cubic centimeter of atropine. Do you get what you should
get? What conclusions can you draw? Stimulate the va-
gus nerve and see if your eye record is affected. What is
the relation between the cervical vagus nerve trunk and the
eye in the dog? How does this compare with a man? If
you get any eye records study and explain carefully the
exact cause of these records. Are they due to local or
remote actions of the drugs concerned?

Empty out the pilocarpine and put barium chloride solu-
tion in the burette. Inject five cubic centimeters (one-half
per cent) of the solution. Obtain as good records as you
can. Then inject sufficient barium to kill the animal. Dis-
cuss the action of the drugs used in this experiment. Com-
pare your results with those obtained by other members
of the class.

EXPERIMENT LXXVII.

Nicotine, Adrenaline, Barium. (Dog: Pulmonary Blood-
pressure, Carotid Pressure.)

1. Etherize a dog (twelve or fourteen kilos preferred).
A small dose of chloretone may be given to some advan-
tage. Arrange for a perfectly reliable artificial respira-
tion (a power driven machine is greatly to be preferred).
Isolate and ligate loosely both vagi. Arrange to record
carotid blood-pressure. The injecting burettes contain nic-

PULMONARY BLOOD-PRESSURE

311

otine (one-half per cent) and adrenaline (1:10,000).
Place the pulmonary manometer in position on the drum.
Its base line should be about one-half inch above the ca-
rotid pressure and the carotid writing point should be able
to pass up just to the left of both pulmonary pointers (see
Fig. 273).

To pulley

Pressure
bottleA

, wire

Pulmonary
)ase lint,
marker

- Pulmonary
manometer

(mercury or salt sol.)

- Cdrotid manometer
(mercury)

Into Cdrotid / ':-=f-:
artery - : =L-

Fig. 273. Arrangement of apparatus for recording pulmonary blood-pressure.

312

EXPERIMENTAL PHARMACOLOGY

By a median longitudinal incision open the thorax. For
the method of giving ether when the chest is open see Figs.

Loose ligature
-Sawed edqe of sternum

Left pulmonary artery
Left pulmonary veins

Lunq, partially

inflated
Pericardium
over heart

.... ^phrenic nerve
snowing over pericardium

Fig. 274. Dissection showing the method of lifting up the left pulmonary artery
with an aneurism needle and tying a ligature loosely around the artery far out next to
the lung tissues.

Hemostet

First ligature tied and
fastened on wall of chest

Second loose ligature
on pulmonary artery

T.T.H.

Fig. 275. The first ligature is tied tightly (at the edge of the lung) and with
a hemostat the end of the ligature is clamped to the edge of the chest wall in such a
manner as to lift up and support the. outer end of the artery (and the left lung). A
second (loose) ligature is placed around the artery ready to tie in the cannula.

53 and 107. TVith four large ligatures tie the chest widely
open as shown in Fig. 106.

Consult the Figures and seek for the left pulmonary

PRELIMINARY OPERATIONS

313

veins. The left pulmonary artery lies just posteriorly and
cephalad to the vein which is nearest the apex of the chest.
Keep to the left of the anterior mediastinum if possible.

Cut close to outer
ligature

Bull-dog on pulmonary
artery close to heart

Fig. 276. A special bull-dog is placed on the vessel near the heart and a notch is
cut in the artery close to the outer ligature with the scissors.

Disconnected tube

to manometer

Cannula in position to be
inserted into

pulmonary artery

rfrtery held open

with forceps

Fig. 277. Method of inserting the special cannula into the artery. (For discussion

see text.)

This keeps the heart on the right side. It is usually ad-
visable to pick up the mediastinum and clamp it to the tis-
sues at the right sawed edge of the sternum. This securely

314 EXPERIMENTAL PHARMACOLOGY

holds the heart over in the right side of the thorax and
thus gives a freer field for the operation. With a probe
(blunt point] carefully dissect loose the pleural (fascia)
covering over the area between the arch of the aorta and
the adjacent pulmonary vein. Beneath this fascial cover-
ing you will find the pulmonary artery.

Consult Fig. 274 and carefullly pass a large aneurism
needle beneath the artery. Free as long a space of the ar-
tery as you can readily isolate. This will average about
three-fourths of an inch. Pass a twine ligature around the
vessel and tie it loosely (Fig. 274). Now with large for-
ceps (using one finger to help hold the twine) slip the liga-
ture outward into the edge of the left lung as far as you
can and then tie tightly. Take hold of the ligature and lift
up the lung as far as you can safely raise it, pass the
ligature out over the chest wall and clamp it with a hemo-
stat to the chest wall. With the aneurism needle still un-
der the vessel pass a second ligature around the artery and
tie it loosely. A iveak-springed, rounded-edged bull-dog
clamp is now placed on the artery as near to the heart as
possible. The loose ligature is placed just peripheral to
the bull-dog.

With the aneurism needle now lift the outer end of the
vessel and cut it about one-half across (Fig. 276) with the
scissors. With his right hand the operator now passes
one of the points of the large sharp-pointed forceps into
the lumen of the vessel and holds it open (the aneurism
needle is held under the vessel with the operator's left
hand) while the assistant inserts the short, wide tip of the
cannula (Figs. 278 and 279) into the vessel. The operator
and assistant (each using one hand) now tie the loose
ligature around the vessel thus fastening the cannula
in securely. It is advisable to leave the washout tube on
the cannula while it is being placed in the vessel but the
manometer tube is best left off until the cannula is securely
fastened in the vessel. This is done on account of the dif-

PRELIMINARY OPERATIONS

315

ficulty of manipulating so many pieces in the chest at one
time. The beating of the heart greatly increases the dif-
ficulties of the operation. The artery has thin walls and a
sharp-edged or strong-springed bull-dog will sometimes
quickly wear a hole in the vessel from the constant rubbing

To manometer

Fig. 278.

-For washout

Fig. 279.

Fig. 278. Special form of separable pointed cannula for the pulmonary artery.

Fig. 279. Special (all-glass) form of cannula for the pulmonary artery. The open-
ing m the point should be about one-eighth inch in diameter (the pulmonary artery is
large).

316 EXPERIMENTAL PHARMACOLOGY

of the ventricle before the manometer can be connected up.

The pulmonary manometer should have its own inde-
pendent base line (which can be a wire fastened to the
board of the manometer). It is most instructive to the stu-
dent to use mercury in this manometer but sometimes wa-
ter or salt solution is used instead. The comparison with
the carotid pressure is seen at once if mercury is used.

Sodium citrate solution is used to prevent coagulation.
A T-tube placed in the tube going down from the pressure
bottle permits each manometer to have its own supply of
citrate solution. When the cannula and tubing are all ad-
justed for the pulmonary pressure (the manometer should
have been fully adjusted previously) then wash out the
tubes and manometer with citrate solution and fill the tubes
full but leave no positive pressure in the tubes. This is of
great importance. To accomplish best results a slight neg-
ative pressure in the tubes is advisable. To get this fill the
tubes and close both pinch cocks. Then open only the one
on the washout. The pressure falls to zero in the manom-
eter. Now between the thumb and finger squeeze the tube
from the artery to the manometer. A small amount of the
citrate solution runs out. Now close the washout and let
go the tube. A slight negative pressure shows in the ma-
nometer but the tubes are full of solution and no air is left
in them.

Work rapidly now for the animal may die soon and a
clot is very liable to form in the pulmonary cannula. Ad-
just all writing points, remove the pulmonary bull-dog and
take a short normal tracing. Inject one-half cubic centi-
meter of adrenaline and get a record. What effect has
this on pulmonary pressure ? Does the pressure rise
higher in the right lung than it does in the left? Does
your experiment demonstrate this? Explain. What nerv-
ous structures are involved in this reaction?

As soon as the normal is reached inject a dose of nico-
tine (three-fourths cubic centimeter). Do you get a satis-

PULMONARY BLOOD-PRESSURE

317

factory record! How does nicotine affect the pulmonary
blood-pressure? AVhat structures are involved? What
mechanical factors are concerned?

If you get a pulmonary clot put on the bull-dog and wash

Fig. 280. Tracing showing the action of adrenaline on the pulmonary pressure, kid-
ney volume and blood-pressure (right carotid) in a dog. The straight line just beiow
the pulmonary pressure tracing is the pulmonary base line.

out the blood but be sure no positive citrate pressure is left
in the tubes. This is necessary because strong (five to ten
per cent) sodium citrate solution is very poisonous to the

318 EXPERIMENTAL PHARMACOLOGY

heart and a small amount can easily pass back from the
pulmonary artery into the right ventricle. This may kill
the heart immediately. Could you use hirudin for this pur-
pose? "What objections could you offer?

The average group of students will not get more than
tAvo good pulmonary pressure records from one dog. If
the animal is still in suitable condition inject five cubic cen-
timeters of barium chloride solution (one-half per cent).
What conclusions can you draw? In how many ways may
drugs affect the pulmonary blood-pressure? How many
of these does your experiment illustrate? "\Vhat differ-
ences are there betAveen the systemic and pulmonary cir-
culation? Historically Avhich of the systems Avas first dis-
coA T ered? By Avhom? Kill the dog Avith a dose of barium.

EXPERIMENT LXXVIII.

Nicotine, Pilocarpine, Atropine. (Dog: Intraocular

Nerves, Salivary Glands, Oxygen Consumption, Blood-

pressure and Respiration.)

(For the anatomy of the eye, see Experiment CXVII,

page 394.)

1. GiA^e a dog (10 kilos) a moderate or small dose of
chloretone and folloAv this with ether. Arrange to record
blood-pressure and respiration. Consult Fig. 281 and dis-
sect out the optic nerve in the right eye. (Consult Experi-
ment LXIII, 2). Study Fig. 281 carefully and dissect out
the orbit until the eye ball can be rolled around forAA^ard (in-
ward) enough to bring the trunk of the optic nerve into
vieAv. The skin around the outer canthus should be cut
aAYay and sometimes the bones of the orbit must also be
chipped out a little Avith bone forceps. Try to aA T oid dis-
turbing the blood A r essels entering the eye from behind.
When the nerve is isolated place the platinum electrodes
against the nerve sheath and, Avhile Avatching the pupil,

INTRAOCULAR NERVES

319

stimulate the nerve. The pupil may dilate (sympathetic
fibers), contract (oculomotor fibers) or remain stationary
(both sets of fibers or none of either). The electrodes are
moved a little and the points can be worked cautiously down
into the nerve trunk. Stimulate (for a moment only) at
each new position of the electrodes, the pupil being watched
carefully all the time. At some point in the stimulation the
pupil will show a marked contraction at once. This is
striking when properly done and will be well worth the
time necessary to do the dissection within the orbit with
especial care. Let each member of the group see the con-

Fig. 281. Method of dissecting out the orbital fat and fascia to expose the optic
nerve. The position of the electrodes for stimulating the third nerve fibers is shown.
The eye-ball is rolled forward (inward) somewhat to bring the optic sheath into view.

traction and keep the observation in mind to check your
later results.

Now turn the dog's head back into the usual position
and insert a cannula into Wharton's duct. Stimulate the
chorda tympani nerve and obtain a normal secretion.

Arrange the apparatus for recording oxygen consump-
tion and if necessary put a small amount of ether into it
(but avoid the ether if you can). Into the femoral veins
place injecting cannulas, the burettes to which contain nico-
tine ( l /2%) and adrenaline. Take some normal record (in-
cluding at least one or two notches of the oxygen record).

320

EXPERIMENTAL PHARMACOLOGY

A good nicotine solution can often be made by scraping
out the contents of the bowls and stems of two or three
tobacco pipes. The material is dissolved in salt solution
and filtered before being placed in the burette for injec-
tion. The results are often striking.

Inject a dose of nicotine (perhaps three-fourths of a
cubic centimeter. This will vary with the size of the ani-
mal and also with the quality of the drug as usually ob-
tained in -the open market). Watch the pupils (both) as
the drug is injected. Do you get a typical blood-pressure
record? If it seems necessary inject some adrenaline to
help restore the animal (watch the pupils as the drug is

Fig. 282. Bone cutting forceps.

injected). What did your oxygen record show? On what
does this depend? Inject another dose of nicotine (esti-
mate the size to suit the tolerance of your animal). Stimu-
late one vagus nerve and see if the heart is inhibited. If it
is, give a little more nicotine cautiously. Stimulate the
chorda tympani and see if secretion follows. When, on
stimulation, the vagus no longer can inhibit the heart,
empty out the nicotine and fill the burette with pilocarpine
solution (one cubic centimeter equals one milligram).
Substitute atropine for the adrenaline in the other burette.
Inject one cubic centimeter of pilocarpine. What action
has this on the salivary secretion and heart ? Have you
injured the vessels going to the salivary glands? Wait a
little and if the animal will tolerate it well inject another

PILOCAEPHSTE AND ATROPINE O_!l

dose of piloearpine. AVait for the action of the drug to
become well developed. How is the heart affected I Stimu-
late one vagus nerve and see if this slows or accelerates
the heart. If it beats faster or if the pressure rises how
do you explain the result? Is this a natural phenomenon
or have the drugs caused it in some way? When the action
of piloearpine is well marked (give more of the piloearpine
if absolutely necessary) inject one cubic centimeter of
atropine solution (one cubic centimeter equals one milli-
gram). Do you get typical results on the heart and blood-
pressure! Stimulate the chorda tympani and see if secre-
tion follows. Another smaller dose of atropine may be
given if the animal will probably tolerate it well.

Now stimulate the oculomotor nerve again and see if
you get a contraction of the pupil. Stimulate the vago-
sympathetic in the neck and see if the pupil dilates. If
time permits dissect out the oculomotor nerve on the left
side and stimulate it to see if contraction of the pupil will
occur. Kill the animal with a big dose of atropine. If
you do not have enough solution to do this (how much does
it take?) then inject nicotine in addition. Examine the
respiratory tracing just after the piloearpine was injected.
Do you note a decrease in the amplitude of the respiration
with some difficulty in either expiration or inspiration?
How do you account for this? Is it central or peripheral?
How did the atropine affect this? Did the atropine act
centrally or peripherally ! Could you obtain such phe-
nomena as this in an animal whose head had been removed
from the body?

After the animal is dead pick up one vago-synipathetic
nerve trunk in the neck and follow it up toward the base
of the skull. Dissect out the superior cervical ganglion
and determine its relations to the surrounding structures.
From this ganglion sympathetic fibers pass to the various
organs, glands, involuntary muscles, etc., of the head. (See
Fig. 243.)

322 EXPERIMENTAL PHARMACOLOGY

EXPERIMENT LXXIX.

Lobeline. (Frog or Turtle: Heart and Inhibitory Nerves.)

1. Pith a frog or turtle and take a heart tracing includ-
ing both vagus and crescent stimulation records. Make up
a solution of lobeline sulphate containing approximately
one milligram of the drug to one cubic centimeter of dis-
tilled water. Lobeline sulphate is a dark, thick, viscid sub-
stance and is difficult to weigh or measure but dissolves
readily in water.

While taking a record on the drum pour a few drops of
the solution on the heart. Do vou note anv immediate

. /

action? Stimulate the vagus nerve and note the action on
the heart. Now stimulate the crescent and see if you ob-
tain the usual result. What conclusions can A^OU draw?

ml

Have you obtained similar results with any other drug?
Could you prove your conclusions in any other way? Ap-
ply more of the drug to the heart to see the later results.
How does lobeline act? (See Edmunds: American Journal
of Physiology, xi, p. 79.)

EXPERIMENT LXXX.

Lobeline, Pilocarpine. (Turtle: Lung Tracing.)

1. Arrange a turtle for taking lung tracings (consult
Experiment LXXIV, 1). When all adjustments are made
take one-half inch of the normal (quiescent) record and
then inject into the ventricle with a very fine-pointed hypo-
dermic syringe one or two cubic centimeters of lobeline
solution (one cubic centimeter equals one-half milligram).
Do not disturb the lung tracing by manipulating the heart
carelessly. Do you get a satisfactory lung record? How
do you explain this action of the drug? On what structures
does lobeline act? Where are these structures located in

LOBELINE, ARECOLHSTE, ATROPINE

323

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O 10

"2. -
3 3

cr - >
o ^

324

EXPERIMENTAL PHARMACOLOGY

the turtle! Do you have any evidence that these structures
exist in the turtle?

As soon as the curve returns to normal prepare to in-

Fig. 284. Turtle lung tracing showing the action of lobeline.

Fig. 285. Turtle lung tracing showing the action of lobeline.

ject piloearpine (one cubic centimeter equals one-half mil-
ligram). The heart may not be beating very strongly and
if this is the case it may be advisable to wait a few minutes
for the heart to recover. A few drops of a dilute (1 :10,000)

LOBELINE, PILOCARPINE, ADRENALINE

325

adrenaline solution may be poured on the heart to ad-
vantage.

Prepare to take a second record and then inject one or
two cubic centimeters of pilocarpine solution into the
heart. AVait for the drug to act as the heart may be
slowed or stopped and the solution may not reach the lung
tissues for some time. Do you get a satisfactory record!
How do you explain this! On what structures does pilo-
carpine act? Do you have any evidence that such struc-
tures exist in the turtle's lungs? \Vliat general conclu-
sions can you draw from the experiment!

Fig. 286. Turtle lung tracing showing the action of pilocarpine.

EXPERIMENT LXXXI.

Lobeline, Adrenaline, Pilocarpine, Tetramethylammonium
chloride. (Dog: Bladder Contraction, Blood-pressure,

Respiration, Pupil.)

1. Arrange an eight kilo dog (the animal may be given
a small dose of chloretone 1.50 milligrams per kilogram
of weight) for recording blood-pressure, bladder contrac-

326

EXPERIMENTAL PHARMACOLOGY

Fig. 287. Tracing showing the action of lobeline (three injections) and heroine on
the bladder, bronchioles and blood-pressure in a spinal dog that had previously received
3 milligrams (intravenously) of atropine.

ACTION OF LOBELHSTE

327

Fig. 288. Tracing showing the action of lobeline (two injections) on the bladder,
bronchioles and blood-pressure in a spinal dog which had previously received a sufficient
amount (135 mgs. ) of heroine to render the animal insusceptible to the specific action
of the drug on the bladder and bronchioles. Evidently here the first dose of lobeline
produced ganglionic paralysis as shown by failure of response to the second dose.

328 EXPERIMENTAL PHARMACOLOGY

tions, and respiration. Isolate and ligate loosely both vagi
nerves. Stimulate one and watch the corresponding pupil-
lary response. Keep this in mind for later comparisons.
The three injecting burettes contain lobeline (one cubic'
centimeter equals one-half milligram), adrenaline (1:10,-
000) and pilocarpine (one cubic centimeter equals one mil-
ligram).

Take one inch of normal tracing. The bladder record
(leave space for an upward contraction) should be on the
upper part of the drum; below this are the blood-pressure,
respiration and base line in succession. Be sure the blad-
der tambour and manometer pointer will just pass each
other on the drum (the tambour to the left). "When all is
ready watch both pupils closely and inject one-half cubic
centimeter of lobeline solution. There should be an im-
mediate and profound response. Do the pupillary, blad-
der and vascular responses all correspond! On what ana-
tomical structures does the drug act to produce each of
these reactions? Could you find these structures in a dis-
section of the animal I Allow the animal to return to nor-
mal.

Inject one-fourth cubic centimeter of lobeline. Do you
get a response corresponding to that produced by the first
dose of the drug? How do you explain this? Could you
prove the truth or falsity of your conclusions ? How would
you do this? AYhen the records return to normal inject
one cubic centimeter of pilocarpine solution. What is the
action of pilocarpine after lobeline ? Do these drugs coun-
teract each other in any respect! Do your records show
this? Explain the results fully. Inject a second dose of
pilocarpine if necessary to get satisfactory records.

Injec-t one-half cubic centimeter of adrenaline and see
if the lobeline and pilocarpine have changed the response
of the animal to the adrenaline in any way. Watch the
pupils closely as the adrenaline is injected. Xow stimulate
each vagus nerve and see how the heart, blood-pressure

TETRAMETHYLAMMOXIUM CHLORIDE

329

Fig. 289. Blood-pressure (and kidney volume) tracing showing the action of
tetramethylammonium chloride before and after the injection of atropine. The first
dose of tetramethylammonium chloride caused a great fall in pressure because the vagus
endings in the heart were intact. The second dose, however, following paralysis of the
vagus endings by atropine, caused a great rise in pressure. The kidney volume also
actii'dv shrinks. To what is this action due?

330

EXPERIMENTAL PHARMACOLOGY

and pupils are affected. Is the respiration changed by the
stimulation ? Have any of these phenomena been influenced
in any way by the drugs If so, what anatomical struc-
tures were involved and how were they affected? Are
these structures ever involved in pathological conditions

Fig. 290. Tracing showing the action of tetramethylammonium chloride on the blood-
pressure and bladder contractions in a dog which had previously received a dose of
atropine. Animal anesthetized by nitrous oxide.

such as typhoid fever or pneumonia? What symptoms
would these reactions probably produce in a non-anesthe-
tized animal?

If the animal is still in suitable condition empty out the
pilocarpine and fill the burette with a solution (one cubic

PILOCARPHSTE, TETRAMETHYLAMMONIUM CHLORIDE 331

Fig. 291. Tracing showing the action of pilocarpine, tetramethylammonium chloride
(two injections) and adrenaline on the bronchioles and blood-pressure in a spinal dog.
Note the peculiar combination of cardio-inhibition and vaso-constriction produced by the
tetramethylammonium chloride which also dilates the bronchioles, while pilocarpine, which
likewise causes cardio-inhibition, produces contraction of the bronchioles. Adrenaline
has still a different action. How do you explain these various phenomena?

332 EXPERIMENTAL PHARMACOLOGY

centimeter equals one milligram) of tetramethylammo-
niiim chloride. Inject one cubic centimeter and determine
what action this drug has after lobeline. What structures
are affected by the drug and how are they influenced ? Kill
the animal with a big dose of the tetramethylammonium
chloride. AVas the bladder contracted before the last drug-
was injected? If so, you may miss part of the action of
the drug.

EXPERIMENT LXXXII.

Lobeline, Nicotine, Pilocarpine. (Guinea Pig, Cat, Dog, or

Rabbit: Uterus Strip.)

(Consult also the following experiment. One animal may
be used for both experiments.)

1. Examine carefully the apparatus shown in Fig. 292.
(Consult also Fig. 316). This simple arrangement is suf-
ficient for ordinary qualitative results but the more elab-
orate apparatus should be used for especially important
experiments such as drug assaying by the uterine strip
method.

The animal used in this experiment may often be ob-
tained from another group of students who have already
performed another experiment. It is important to save as
many animals as possible. If a dog or cat is used it must
first be etherized, then one horn of the uterus (including
the ovary) is dissected out very carefully so as not to in-
jure the tissues. From this a small uterine strip is pre-
pared and with a bent pin hook one end of the uterine strip
is attached to the loAver end of the bent glass tube as shown
in the picture. By another pin hook and a small thread the
upper end of the tissue is attached to the short arm of the
heart lever. The lever is weighted on the long end by a
(movable) bull-dog clamp. If a guinea pig is used (and
these animals are very satisfactory) it may first be anes-

UTERINE STRIP RECORDS

ooo
ooo

thetized or its head may be instantly cut off with a hatchet
or sharp hand ax. The animal may be anesthetized with
nitrous oxide (see Experiment VII) if it can be killed in a
few seconds after it is removed from the large bottle.
Ethyl chloride may also be used instead of ether.

As soon as the uterine strip is adjusted in the beaker,
warm (38) normal salt solution (or Locke's solution, etc.)

Q/ass
tube-

ormal salt sol. 37'c
Uterus strip ^

Removable beaker

Fig. 292. Arrangement of apparatus for recording contractions from a uterine strip, or
from an arterial ring, ureter ring, intestinal strip, ring of frog's stomach, etc.

is placed in the beaker. The writing point of the lever is
brought on to the drum which is started at the slowest
speed. Small rhythmic contractions should be recorded.
When sufficient normal records have been taken (there are
great variations in the normal contractions exhibited by
different uteri) then with a pipette pour one or two (or
more) cubic centimeters of a solution of lobeline (one
cubic centimeter equals one milligram) into the beaker.

334 EXPERIMENTAL PHARMACOLOGY

The oxygen should be bubbling slowly but constantly
through the solution. This serves not only to oxygenate
the solution but also stirs it. Do you get a response to
the lobeline ? How do you explain the result 1 After a few
minutes slip the lower beaker out and replace the upper
one by another containing fresh warm salt solution. How
does the uterine strip respond to this? Take some more
normal tracings and then pour one or two (or more) cubic
centimeters of nicotine solution (one per cent) into the
beaker. Discuss your results fully. Change the beaker
again replacing it with one containing fresh warm salt
solution. Get some more records and then pour a small
amount of pilocarpine solution (one cubic centimeter equals
two milligrams) into the beaker. Discuss the results in
full. Add some atropine solution to the beaker and see if
this affects the uterine strip. (The size of the "dose" of
the drugs used in this experiment may have to be varied
a great deal in different experiments. The doses here
given will often be too large but the student can test this
out for himself.)

EXPERIMENT LXXXIII.

Adrenaline, Lobeline, Nicotine, Pilocarpine, Atropine.

(Guinea Pig, Rabbit, Dog, Cat, Frog:

Intestinal Segment.)

(Consult the previous experiment to save animals.)

1. Repeat the above experiment using a small ring cut
from the small intestine of one of the above mentioned ani-
mals. Do not injure the intestine if it can be avoided in
making your dissection. Be sure the intestinal ring is
properly weighted (try different weights to select the right
one) and then record some normal contractions. Add
some adrenaline (1:10,000) to the beaker and record the
results. How do you explain this? Change solutions and

LOBELINE, ADRENALINE, NICOTINE, ETC.

335

when normal contractions again occur add some lobeline
solution to the beaker. Explain the results. If a contrac-
tion is produced counteract this by adding adrenaline to
the beaker. Repeat this process with nicotine and pilo-
carpine. (It may be necessary to use a fresh ring of in-

Fig. 293. Tracing showing the action of muscarine on intestinal contractions, respiration

and blood-pressure in a dog.

336 EXPERIMENTAL PHARMACOLOGY

testine.) Again add pilocarpine to the beaker and if a
contraction is produced then add atropine solution (one
cubic centimeter equals five milligrams). Do you obtain
satisfactory results ? State in full your conclusions. Add
some barium chloride (one-half per cent solution) to the
beaker and note the results.

A part or all of the experiment may be repeated by us-
ing a longitudinal strip of the small intestine. What effect
does adrenaline have on longitudinal strips? What is the
innervation of the small intestine ? (Fig. 318).

The experiment may be repeated using a ring of the
stomach of a frog.

EXPERIMENT LXXXIV.
Muscarine, Atropine. (Turtle: Lung- Tracings.)

1. Prepare a turtle for taking lung tracings. Inject into
the heart one or two cubic centimeters of muscarine solu-
tion (one cubic centimeter equals one-halt' milligram) and
record the result. Do you get a contraction of the lungs?
How do you explain your results? Is the heart beating
well? Inject one or two cubic centimeters of atropine solu-
tion (one cubic centimeter equals one-half milligram). Do
you get a contraction or a relaxation of the lungs ? How do
you explain the results ? Perhaps you may want to repeat
the injection of atropine on a second turtle. How do your
results compare with those obtained in a dog or cat ?

If the lungs relax after a contraction can the relaxation
be recorded if the weight of the liver and intestines is rest-
ing on the pulmonary sacs? Could you modify the experi-
ment to advantage in any way? It is usually advisable to
dissect out the liver and intestines and most of the skeletal
muscles before trying to record lung contractions. Do not
injure the vessels going to the lungs.

Serosa

huscularis
Circular
Longirudindl
fibers

Submucosa
Muscularis

mucosd
Villi and

glands

.^^^X ~ Blood vessels

Auerbach's plexus

(between muscle Idyers)

eissner's plexus

( in submucosa )

1 1 Preganglionic

n " /"

-Postganglionic fiber

-Sympathetic fiber
(inhibitory)

I' IK. 294. Diagrammatic cross-section of the intestine (small) to show the manner of its

innervation. See also Fig. 318.

ACTION OF PHYSOSTIGMIjSTE 337

EXPERIMENT LXXXV.
Physostigmine. (Frog 1 : Heart Tracing 1 .)

1. Pith a frog and obtain heart tracings showing the ac-
tion of physostigmine (eserine). The salicylate of eserine
is the best salt to use, the sulphate is deliquescent one
cubic centimeter equals one milligram. The solutions
should be freshly prepared for each experiment.

Fig. 295. Turtle heart tracing showing the action of nicotine, arecoline and atro-
pine. At the places marked R.l'.S.. the right vagus nerve was stimulated. Before
nicotine inhibition is produced but this is absent after the drug is applied. Note the
temporary slowing of the heart immediately following the application of the drug. How-
do you explain this? The beat again becomes rapid but arecoline slows it while atropine
causes a return of the normal rate. Explain the actions.

Does the drug have any action on the inhibitory appa-
ratus of the frog? Compare this with pilocarpine.

EXPERIMENT LXXXYI.

Physostigmine, Atropine, (Sodium Nitrite. (Frog:

Stomach Ring.)

1. Prepare a ring of the stomach of a frog and arrange
it in the manner shown in Fig. 292 for recording contrac-
tions on the drum. Is the muscle ring already in a state of

338 EXPERIMENTAL PHARMACOLOGY

strong tonic contraction! If it is, can it contract any
further? Adjust the weight and pour into the beaker one
or two cubic centimeters of eserine solution. (Add more
drug if necessary.) What conclusions can you draw? Add
some atropine to the beaker and note the results.

The experiment may be repeated (a fresh stomach ring
may be needed) and after the eserine action has been well
developed sodium nitrite solution (one-half per cent a
few cubic centimeters) can be added to the beaker. What
do you observe? What conclusions can you draw? On
what structures and in what manner does each drug act?
Of what clinical significance is each of these actions?

EXPERIMENT LXXXVII.
Physostigmine. (Turtle: Heart Tracing.)

1. Repeat Experiment LXXX.V using a turtle instead of
a frog. Does the drug act in any way on the crescent
ganglia or the post ganglionic fibers? Compare this with
nicotine and arecoline.

EXPERIMENT LXXXVIII.

Physostigmine, (Adrenaline, Atropine). (Turtle:

Lung Tracing.)

1. Arrange a turtle for recording lung tracings and then
inject into the heart one or two cubic centimeters of eserine
solution (one cubic centimeter equals one-half milligram).
What action has the drug in this case? Is this a ganglionic
or nerve ending reaction? Could you prove your conclu-
sion? Now make a second injection of eserine into the
heart (if it has not already become too weak or stopped)
and follow this with an injection of adrenaline (1:1000).
Atropine may be used instead of adrenaline (or better a
second experiment on a fresh animal may be performed).

PHYSOST1GMINE, HYOSCINE, ADRENALIN K 339

What conclusions can you draw? Do atropine and adren-
aline act on the lungs of the turtle in the same way that
they do on the dog's lungs? Could you prove your conclu-
sions?

EXPERIMENT LXXXIX.

Physostigmine, Hyoscine, Adrenaline, (Trimethylamine).

(Dog: Respiration, Blood-pressure, Intestinal

Contractions.)

(See following experiment.)

1. Arrange a dog (a cat or rabbit may be used) for
recording blood-pressure, respiration, and intestinal con-
tractions. (For the latter purpose use the ringer cot, cathe-
ter, burette, and tambour method.) The three injecting
burettes contain physostigmine (one cubic centimeter
equals one-half milligram), hyoscine (one cubic centimeter
equals one milligram atropine or hyoscyamine may be
substituted could you use homatropine?) and adrenaline
(or trimethylamine hydrochloride one cubic centimeter
equals one milligram).

Take a normal record and then inject two cubic centi-
meters (for a cat or rabbit one-half cubic centimeter) of
physostigmine. How is the respiratory tracing affected !
Do you get normal results from the heart and intestine I
Was the dose too large or too small? The instructor may
be able to advise you on this point, because he can observe
the action of the same drug solution you are using in the
experiments performed by other members of the class. As
soon as the action of the eserine becomes well marked in-
ject a dose (one-half cubic centimeter for a dog) of
adrenaline (or trimethylamine, one cubic centimeter).
What action has this on the respiration? Does it counter-
act the eserine? Explain the relations of these two drugs
to the respiration both centrally and peripherally. How is

340

EXPERIMENTAL PHARMACOLOGY

the eserine intestinal reaction affected by adrenaline?
What structures are involved and how are they affected?
What is the innervation of the intestine ? Would it be ad-
visable for a physician to understand this innervation?
How could he best learn the nervous control of the intes-
tinal movements?

Fig. 296. Tracing showing the action of trimethylamine on the bronchioles and
blood-pressure of a spinal dog. The bronchioles were in a state of moderate contrac-
tion from the effects of a dose of pilocarpine at the beginning of the tracing. Record
made by aspiration of the chest. (See Experiment LXX.)

Wait till the animal returns to normal. Take another
starting record and inject a second dose of physostigmine.
You can estimate the correct size of this dose from the re-
sults of your first injection. When the action of the drug
becomes marked on the animal quickly observe the mouth

PILOCARPIXE AXD TRIMETHYLAMINE

341

for saliva, the pupils for change in size, and the respira-
tory movements for difficulty in expiration or inspiration.
At once inject one cubic centimeter of hyoscine (for a dog.

Fig. 297. Tracing showing the action of pilocarpine and trimethylamine on the
bronchioles and blood-pressure in a spinal dog. Record made according to the method
described in Experiment XXIX.

one-half cubic centimeter for a cat or rabbit) and observe
the effects. What conclusions can you drawl Atropine or
hvoscyamine mav be substituted for the hvoscine. How

/ / ' /

does the action of eserine compare with that of pilocarpine

342 EXPERIMENTAL PHARMACOLOGY

or muscarine or arecoline? What differences do YOU note?

&

Stimulate one vagus nerve to see if the heart can be in-
hibited. If so give another dose of hyoscine (or atropine
or hyoscyamine ) .

If the animal is still in fair condition inject another dose
of physostigmine to see if the respiration, intestine and
circulation are affected in the same way as they were be-
fore the atropine was given. Do you observe any fine mus-
cular tremors over any parts of the animal? Were these
present before the atropine was given? Has the atropine
affected the tremors in any way! Explain. If you get a
marked intestinal reaction then inject one cubic centimeter
of adrenaline and see what occurs in the intestinal record.
Explain fully.

Kill the animal with a large dose of eserine. Which stops
first, the heart or respiration? Save the animal for the
following experiment.

EXPERIMENT XC.

Adrenaline, Sodium Nitrite, Barium Chloride. (Dog 1 , Cat
or Rabbit: Perfusion of Kidney.)

(See preceding experiment. Dog's kidneys are much to

be preferred.)

1. Observe carefully the arrangement of the apparatus
shown in Fig. 298. The water motor has a wire rod at-
tached eccentrically bv a screw to the end of the shaft.

i-

This rod passes up to the shelf above and ends in a curved
hook which moves rapidly up and down and thus inter-
rupts the flow of normal salt solution (or diluted, defibrin-
ated blood) from the pressure bottle (or bottles) above.
This mechanical interruption fairly closely approximates
the action of the heart in producing a pulsation in the
arteries carrying blood to the various organs.

The apparatus should all be set up and in full working

PERFUSIOX APPARATUS

343

condition with the water bath heated to 38 or 39 degrees
Centigrade before the animal is killed. Also a dish of warm
salt solution, three small cannulas (for the kidney vessels
and ureter), threads and a rubber bulb (1 or 2 oz.) carry-
ing a small pointed cannula should be prepared. The bull)
is used to flush out the vessels of the kidney immediately

Cannula in

-(.annula. in Vein

annula in Ureter
fV Openma for osnnulas

Fig. 298. Arrangement of apparatus for perfusion of an excised organ. (For discus-
sion see text.)

after excision. This prevents clots from forming in the
capillaries and smaller vessels of the organ.

As soon as the animal dies the abdomen is opened and
the left kidney is carefully excised, leaving the artery, vein
and ureter as long as possible. The kidney is immediately
transferred to the dish of warm salt solution, the rubber

344 EXPERIMENTAL PHARMACOLOGY

bulb is drawn full of the solution and the point of the
cannula is inserted into the cut end of the renal artery.
The cannula can be held in temporarily while the bulb is
squeezed with a moderate but firm pressure. The blood is
soon flushed out of the kidney vessels. Cannula s are then
quickly tied in the renal artery, vein and ureter. The
kidney is transferred to the small chamber shown in the
upper left hand corner of Fig. 298. This chamber is made
of a large, deep metal pill box having a notch cut out of
the upper side. Through this notch the three cannulas are
passed and then the broad rubber band (which was al-
ready around the box) is slipped over the notch while the
three cannulas in order are passed through holes (air
tight) made in the rubber band. The lid is then placed on
the box and the rubber band is slipped over the seam be-
tween the lid and the box proper thus making the cham-
ber air tight. The box is then connected up as shown in the
picture and the stock solution is started through the tubes
(from which all air has been previously expelled). The
motor is started and the pressure bottle is raised to a
height just sufficient to give the maximum excursion to
the tambour pointer at each pulsation of the fluid in the
tubes. The solution passes through the kidney slowly and
fresh (warm) solution should be run down into the tubes
occasionally.

When all adjustments are made take one-half inch of
normal record and then with a hypodermic syringe inject
some adrenaline solution in the tube above the artery as
illustrated. A response should be obtained at once on the
drum if the circulation through the kidney is good. Wait
for the kidney to expand again. How do you explain these
results! As soon as the contraction wears off (or a little
before) inject one or two cubic centimeters of sodium
nitrite solution (one-half per cent) into the rubber tube.
Xote the effect when this reaches the kidney. Explain the
results in full.

PEKFUSIOX OF THE KIDNEY

345

When a satisfactory record has been obtained examine
the temperature of the solution entering the kidney and if
necessary change the pressure of the perfusion fluid. (It
may be advisable to flush out the organ by temporarily
increasing the pressure considerably.) When everything

srerwsrvut. off- JjiAM^AjuL <Jdd/nJUJ

off ** aif-a..
"

Fig. 299. Tracings made by the use of the apparatus shown in Fig. 298, showing
the action of sodium orthovanadate, barium chloride, and adrenaline on the volume of
an excised kidney from a dog. (For discussion see text. )

is again ready inject one or two cubic centimeters of
barium chloride solution (one-half per cent). Wait for the
drug to pass into the kidney. The circulation often be-
comes slow in organs thus perfused. Do you get a satisfac-
tory record ? Explain the action of the drugs studied.

346 EXPERIMENTAL PHARMACOLOGY

The right kidney or the spleen of the same animal may
be used by other members of the class if sufficient appara-
tus is available. The motor and the pulsations in the per-
i'usion fluid may be omitted it' the apparatus cannot be ob-
tained. The interrupted pressure is. however, much to be
preferred as it is more effective in keeping up the circula-
tion through the organ (and edema of the tissues may be
prevented or much delayed in its appearance). The tin
box chamber (oncometer) may be omitted and the rate of
perfusion determined by counting the drops of solution
leaving the vein. It is advisable, however, to get a volume
record of the organ.

Many forms of perfusion apparatus have been devised
and the student may find it necessary to use an outfit very
different from that here described. (For description of an
excellent perfusion apparatus, see Richards, A. X., and
Drinker, C. K.: Journal of Pharmacology and Experi-
mental Therapeutics, 1915, vii, pp. 467 to 483.)

EXPERIMEXT XCI.

Physostigmine, Atropine, (Heroine), Adrenaline. (Spinal

Dog or Cat: Bronchioles, Blood-pressure, and

Bladder Contractions.)

1. Arrange a spinal dog (or cat if dogs are not avail-
able) for recording blood-pressure, bladder and bronchiole
contractions. It is very advisable that the lung records be
obtained by the aspiration method using the apparatus
shown in Fig. 255. Pith the animal by destroying the brain
through a trephine opening (Fig. 260). (Also read Experi-
ment LXX.) The arrangements for recording the bladder
contractions should be made (except attaching the record-
ing tambour as this would interfere with the operations)
before the apparatus used to hold the chest open is inserted
and this should be done (under positire artificial rexpira-
iion) before the animal is pithed, irliicli is the last opera-

ESERIXE, ADRENALINE, ATROPIXK 347

tion done before the records are started. This sequence
of operative procedures is followed in order to save the
vitality of the animal as much as possible a spinal animal
may not stand operations well. The injecting- burettes
contain eserine (one cubic centimeter equals one milligram),
adrenaline (1:10,000), and heroine (one cubic centimeter
equals five milligrams other opium alkaloids, e. g., co-
deine, etc., may be used instead of heroine).

When all apparatus is arranged take half an inch or
more of normal record and then inject one cubic centi-
meter (dog) of eserine. Do you get satisfactory bladder
and lung records ? A moderate dose of physostigmine has
been found to render the endings of the vagi nerves in the
bronchoconstrictor muscles more irritable than normally.
Allow the animal to recover as much as possible from the
drug and then stimulate each, or both, vagus nerves and
determine exactly what influence they possess over the cali-
ber of the bronchioles. Use varying strengths of the Fara-
dizing current and also try varying lengths of duration of
stimulation. It may be further instructive to use a series
of single shocks of varying strengths and duration to bring
out any bronchial changes. What conclusions can you
draw? (See Dixon and Brodie: Journal of Physiology,
1903, xxix, p. 119; also Dixon and Ransom, ibid, 1912.)

Get the animal into as good condition as possible (give
adrenaline if necessary) and then inject a second dose of
eserine. When the effects come on inject one-half cubic
centimeter of adrenaline to counteract the eserine. Do
your records show normal results? \Vas the dose of
eserine of the right size? (Von must learn to estimate the
dose to suit your animal often the instructor can help
you here.)

When the animal recovers give another dose of eserine
or, if a bronchial constriction returns after the adrenaline
effects wear off, omit tlie eserine and then inject one cubic
centimeter of atropine solution (one cubic centimeter equals

348

EXPERIMENTAL PHARMACOLOGY

one milligram dog) and thus counteract the eserine ac-
tion. How does the bladder respond to these drugs?

If the animal is still in a suitable condition inject five
cubic centimeters of heroine or other (phenanthrene) de-
rivative of opium (dose for an eight kilo dog) and see if

Fig. 300. Tracing showing the action of heroine and adrenaline on the bronchioles and
blood-pressure in a spinal dog. Made by aspiration of the chest.

you can get a bronchoconstriction or a bladder contrac-

v o

tion after atropine. Counteract this with adrenaline (one
and one-half cubic centimeters dog).

How does eserine affect the respiration in a normal ani-

PRACTICE DISSECTIONS 349

mal '! Does the action of the drug on the bronchioles in
this experiment indicate any way in which the drug might
affect the normal respiration aside from its direct action
on the respiratory center? Do you know of any disease in
which the lungs mat/ be affected in a manner similar to
that brought about by eserine? Do you know of any
remedy that might be used to counteract each condition!
How might the remedy be applied? Stop the artificial
respiration and kill the animal.

2. After death (if you have used a dog) shave the hair
off of an area about three inches long and three inches wide
over the lower part of the dorsal region of the spine. With
a scalpel make a small incision in the skin about one-half
inch to one side of the mid-line of the spinal column. A
small trocar or a long syringe needle (or even a knitting
needle) is now passed into the spinal canal, the needle or
trocar being directed inward, mesially and slightly toward
the head. By consulting a text-book on anatomy the stu-
dent can determine about what relation the point of inser-
tion of the needle through the skin should bear to the lower
end of the nearest spinous process. See if you can get
some spinal fluid to run out of the needle after it is in-
serted. Two or three punctures may be made for practice.
The needle is then left in position and the tissues are dis-
sected away around the needle down to the vertebrae and
the position and relations of the needle are carefully
studied. If you failed to pass the needle into the spinal
canal what was the cause? Could you now succeed in a
living animal! Sketch in your note book the relations of
the spinous processes to the openings into the spinal canal
and save for reference. Examine the size, structure and
relations of the spinal cord. Can you isolate the posterior
and anterior roots and the spinal ganglia? What are the
functions of these structures?

350 EXPERIMENTAL PHARMACOLOGY

EXPERIMENT XCII.
Cocaine. (Frog: Central Nervous System.)

1. Pith a frog (cerebrum only) and wait a while for the
animal to recover from the shock. Then inject into the
anterior lymph sac one cubic centimeter of cocaine hydro-
chloride solution (one cubic centimeter equals five milli-
grams one-half per cent).

Observe the symptoms produced and save the animal for
several hours (if it lives) to note the later action of the
drug. AVhat conclusions can you draw! Do you find any
evidence of central nervous stimulation! How is the rate
of beat of the lymph hearts affected!

EXPERIMENT XCIIL

Cocaine, Physostigmine. (Rabbit, Cat, Dog, Pigeon,
Sparrow, Chicken, Rat: Action on Pupil.)

1. Into the right eye of as many of the above animals as
you can obtain inject ten drops of a one per cent solu-
tion of cocaine hydrochloride. Open the lids, drop in the
solution and try to hold the eye open a while to insure ab-
sorption. Wait ten minutes (examine the pupils from time
to time) and then inject into the left eye of each animal ten
drops of a solution of eserine (one cubic centimeter equals
five milligrams). Observe both pupils carefully from time
to time and when the actions of the drugs come on try the
light reflex to see if the pupil contracts when a bright light
(pocket flash light, lighted match, or It right light from a
window, etc.) is suddenly thrown into the eye. On what
does this light reflex depend! Explain in detail the nerv-
ous paths involved in its production. What differences do
you note in the actions of the two drugs! On what struc-
tures does each act and how! How do these drugs affect
the intraocular pressure! How is this brought about!

COCAIXE AND NOVOCAINE 351

EXPERIMENT XCIV.
Cocaine, Novocaine. (Local Anesthetic Action.)

1. Cut a piece of filter paper one-half inch square and
saturate it with two per cent cocaine hydrochloride solu-
tion. Place the filter paper on the right side of the upper
surface of the tongue. Repeat this for the left side of the
tongue but use a two per cent novocaine solution in this
case. Do not swallow any of the solutions. Keep the
pieces of paper on the tongue for a few minutes (the same
for each drug) and then remove them. From time to time
test the sensitiveness of the two spots on the tongue to
touch, pain (pin point) and to minimal induction currents.
What can you say regarding the comparative local actions
of the cocaine and novocaine! If larger areas of the tongue
are covered by the solutions (to include the taste organs,
especially the tip and edges of the tongue) then the taste
sensations for sweet, salt, acid and bitter may be tested.
On what parts of the tongue are the taste organs to detect
each of these sensations located? What conclusions can
you draw from the experiment? Are the sensations of
heat and cold affected or could you determine this from
your experiment? Explain in detail.

EXPERIMENT XCV.

Cocaine. (Frog or Turtle: Heart Tracing 1 .)

1. Pith a frog or turtle and test the action of cocaine on
the heart and cardiac nervous mechanism using a solution
containing two milligrams to one cubic centimeter of solu-
tion. Stimulate the vagus before and after the drug is
applied. Repeat this carefully in each case for the crescent
also. What conclusions can you draw? Have you tested
other drugs having a similar action? If so what ones?

352

EXPERIMENTAL PHARMACOLOGY

AVliat structures are involved in this action ? Keep taking
records and watch for a characteristic grouping of the
beats in fours, threes, twos, etc. The drug is especially
liable to produce this result.

What action would nicotine or lobeline or pilocarpine or
strychnine have on the frog or turtle heart after cocaine
had produced its first effect on the organ? Is this action
the same in the mammal? Explain.

Fig. 301. Frog heart tracing showing the later effects of cocaine. Note the group-
ing of the beats. The earlier effects on the innervation of the heart are not shown in
the tracing.

EXPERIMENT XCVI.
Cocaine. (Frog: Action on Muscular Work.)

1. Arrange your apparatus as shown in Fig. 224. Pith
a frog and ligate the right thigh tightly to stop the circu-
lation in the corresponding gastrocnemius muscle. Into
the dorsal lymph sac inject one cubic centimeter of cocaine
solution (one cubic centimeter equals two milligrams).
Arrange the frog with its right gastrocnemius muscle at-
tached to the lever as shown in the picture. The secondary
wires are made of very fine flexible copper and carry the
current directly to the muscle. Keep the muscle damp

COCAINE, NOVOCAINE, BARIUM, ADRENALINE 353

with normal salt solution. Meanwhile the drug is being
carried to the other gastrocnemius muscle.

When all is ready take a normal fatigue tracing on the
lower part of the drum. Then lower the drum and reverse
the frog board and corresponding pieces of apparatus as
described under caffeine (Experiment XL VII, page 245).
Ligate the left thigh and take a fatigue tracing from the
left gastrocnemius muscle which has in the meantime come
under the influence of the cocaine. How do the two curves
compare as to height of contractions and relative amount
of work done! If there is a difference to what is it due!
Are any nervous structures involved? Are you sure the
rate of stimulation remained the same in both tracings?
Would a slight variation in this produce much effect on
the tracings? How does the action of cocaine compare
with that of caffeine on muscular work?

EXPERIMENT XCVII.

Cocaine, Novocaine, Barium, Adrenaline. (Dog- or Cat:

Respiration, Blood-pressure, Intraocular Pressure,

Local Vascular Action and Intestinal

Contractions.)

1. Arrange a dog (or cat) for recording blood-pressure,
respiration and intestinal contractions, the latter by means
of the finger cot, catheter, burette and tambour method.
While the abdomen is open pick out a small area of the in-
testinal or mesenteric wall where the tissues look pink
(many small vessels) and paint the area with cocaine hy-
drochloride solution (two per cent). Also paint a second
area with novocaine solution (two per cent). Do not ex-
pose the viscera more than can be helped but observe these
two areas closely for several minutes to see if any change
in the appearance of the tissues occurs. If so how do you
explain it? On a third small area of the intestine put one

354 EXPERIMENTAL PHARMACOLOGY

drop of barium chloride solution (one per cent). Watch
this area for a few minutes and record your results. A
fourth area should be treated with one drop of adrenaline
solution (1:10,000). "\Vatch this spot a while and compare
all the areas together. AVhat conclusions and what ex-
planations can you offer ?

Close the abdomen and arrange to record the intra-
ocular pressure (see Fig. 271). The injecting burettes con-
tain cocaine hydrochloride ( one cubic centimeter equals five
milligrams) and adrenaline (1:10,000). On the drum the
highest record should be the intraocular pressure, next be-
low the intestinal record, then the blood-pressure, respira-
tion and base line (showing the time intervals).

Take a short normal record and inject one-half cubic
centimeter (dog) of cocaine solution. From time to time
cautiously inject more cocaine and note the reactions of
the animal to the drug. Observe the pupils, palpebral, fis-
sure, nictitating membrane and eye ball as a dose of the
drug is injected. Are there any movements of any of these
organs"? Continue the observations and stimulate the cor-
responding vagus nerve. AVhat effect does this have on
the palpebral fissure ? How do you explain it ? Does the
eye ball move ? If so what muscles do this and what is their

*/

innervation? Has the intraocular pressure been affected?

Inject one-half cubic centimeter of adrenaline while still
observing the eye and record the results. Explain all
phenomena observed.

Continue to inject cocaine slowly from time to time and
watch for irregularities in the respiration.

(The animal should not have been given any morphine.
It is a very good rule never to give morphine to animals
for ordinary experiments unless there is some special rea-
son for so doing. Ether is the best anesthetic, and a small
amount of chloretone may often be given to some advantage
but even this frequently causes serious cardiac or respira-
tory disturbances.)

COCAINE AXD BARIUM o.V)

Cocaine often causes Cheyne-Stokes respiration. Can
yon produce this in your animal ? (What other drugs often
give this form of breathing f)

What action has cocaine on the intraocular pressure?
Does your experiment demonstrate this! Will the method
of application of the drug affect the result ! If so drop
some cocaine solution into the eye from which you are
making your records. Does this have any effect! Will it
be absorbed! Watch the pupils.

What action have small doses of cocaine on the blood-
pressure! Is this action increased by larger doses! What
is the treatment for cocaine poisoning! Would you ad-
vise giving a drug to lower the blood-pressure in this con-
dition! Would the presence of an anesthetic in your animal
make any profound change in the pharmacological action
of cocaine ! Have you used pure drugs ? What are your
conclusions!

Wait a reasonable time for Cheyne-Stokes respiration
to develop. Then empty out the cocaine solution and place
barium chloride solution (one-half per cent) in the burette.
Adjust all writing points and take a normal record. Inject
four cubic centimeters (dog) of barium solution (five cubic
centimeters if the dog weighs ten kilos or more) and get a
record showing the action of the drug. How is the intestine
affected! The intraocular pressure?

Again empty out the barium and refill the burette with
novocaine solution (one cubic centimeter equals five milli-
grams). Get the animal into as good condition as possible
(give adrenaline if necessary) and then take a normal rec-
ord. Inject one-half cubic centimeter of novocaine solution
and compare the action with that of cocaine. Inject a
larger dose. Which is more toxic, cocaine or novocaine!
(Your animal may not be nearly so sensitive now to small
doses of drugs as it was in the beginning.)

Empty out the novocaine and refill the burette with co-
caine solution. Adjust all writing points and inject a large

356 EXPERIMENTAL PHARMACOLOGY

dose of cocaine to get a death record. Are convulsions pro-
duced? "What conclusions can you draw? Which is more
poisonous, cocaine or pilocarpine?

2. After the animal dies dissect out the thoracic duct
at the root of the neck. See if you can do this without pene-
trating the chest cavity. (See Figs. 302 and 319.) Do you
find the lymphatic vessel coming from the head region ?

3. Turn the body of the animal over on its side and dis-
sect out a section of the back bone covering two or three
vertebra?. Cut away the lamina? and remove the spinous
processes from two or three vertebra?. Can you isolate the
cord? How large is it? Can you make out the anterior
and posterior nerve roots? Locate a posterior nerve root
ganglion. What is the function of this ganglion? Does this
bear any relation to the action of cocaine? If so what?
Could you pass a long hypodermic needle through the skin
and tissues of the back down into the spinal canal ? Study
the anatomy of these structures carefully and try to decide
on what technic you would use in making a spinal puncture.

EXPERIMENT XCVIII.
Novocaine. (Dog: Spinal Anesthesia.)

(This experiment should be performed only at the discre-
tion of the instructor, and then by students who have
some knowledge of aseptic operations. It may
be done as a demonstration.)

1. Sterilize by boiling in water for five minutes a good
hypodermic syringe having a large needle at least two
inches long. Prepare a novocaine solution (two per cent)
and sterilize it by boiling for a brief period of time. Cool
the solution but see that it does not become contaminated
with airy organisms. (Keep it in a sterile test tube plugged
with sterile cotton). Place on the operating table a razor
(clippers are also desirable), a pan of strong soapsuds,

Lext. jugular vein

Lcommoniu
lymphatic nun

Sterno-mattoid
muscle (cut)

5terno-hyoid
muscle
(cut)

Cords of
L Brach.plex

L.subclavian v.

Thoracic
duct

Fig. 302. Dissection showing the method of exposing the lymphatic ducts and con-
necting cannulas to collect the lymph or chyle. It is very desirable to avoid entering the
apex of the chest cavity when a cannula is placed in the thoracic duct.

PRELIMINARY OPERATIONS 357

some cotton sponges, a bottle of alcohol (95%), a bottle of
tincture of iodine, a large pan containing a liter of water
and a bottle of liquor cresolis compositus. Two or three
sterile towels may be used to advantage.

The operator washes and scrubs his hands thoroughly
with soap and water and waits for the assistant to prepare
the animal.

When all preparations are made a dog weighing prefer-
ably about ten kilos is gently placed on its left side on the
operating board and tied down. Do not excite or scare

Fig. 303. Metallic muzzle (made of sheet brass) for administering an anesthetic to
a dog by the closed method. A heavy, perforated rubber membrane is tied (with wire)
over the rear end of the muzzle. The animal's nose and mouth are thrust through the
opening in the rubber membrane.

the animal. Nitrous oxide and oxygen are then admin-
istered to the animal until it becomes unconscious. This
is best done with an apparatus like those shown in Figs.
116, 118, and 172. It usually requires at least ten minutes
to get a dog fairly deeply anesthetized with nitrous oxide
(and oxygen). It is assumed that the students have previ-
ously had some experience in giving nitrous oxide to dogs
in the experiments in the earlier part of the course. The
animal has the metal muzzle (Fig. 303) placed over its nose

358

EXPERIMENTAL PHARMACOLOGY

and mouth and the muzzle is connected to the apparatus
directly, the muzzle flange being slipped over the spout on
the pan. The connection is made air tight by a broad rub-
ber band. The pan is filled with pure X 2 and the anes-
thesia is brought on as rapidly as possible. Oxygen is
added in small quantities as needed. (The usual mistake
is in giving too much oxygen.) AVatch the pulse by keeping

Fig. 304. View of the reverse side of the metallic muzzle shown in Fig. 303. The
flange which is not being used is closed by a rubber stopper.

one finger over the left femoral artery all the time. The
heart will become slow but a little fresh oxygen will ac-
celerate it (this sometimes acts almost like giving adrena-
line so far as one can tell by feeling the pulse).

As soon as the animal becomes quiet an assistant scrubs
an area about four inches in diameter over the lumbar por-
tion of the spinal column vigorously with soap and water.
The hair over the area is then clipped and the skin is shaved
closely. The area is washed thoroughly with alcohol and
allowed to dry. Tincture of iodine is then painted (with a
small cotton sponge) thoroughly over the area.

An assistant now pours about half an ounce of the com-
pound cresol solution (lysol may be used) into the water in
the large pan. The operator mixes the cresol (or lysol) in
the water and thoroughly scrubs his hands in the solution.

IXTRASPIXAL ANESTHESIA 359

Some alcohol may now be poured on the operator's hands
(he should not wipe this oft'). The operator now takes up
the syringe which had been laid on a sterile towel to cool.
Great care must be used to see that neither the syringe nor
the operator's hands touch anything which has not been
sterilized. The operator now draws the barrel of the syringe
full of the novocaine solution. The syringe point is then
detached from the barrel of the syringe which is laid aside
on the sterile towel (or in a sterile pan a metal pan can be
quickly sterilized by pouring a few cubic centimeters of
95% alcohol into it, flowing the alcohol over all the inner
surface of the pan and then setting fire to the alcohol.
When the pan cools it is ready for use.)

The operator selects a point of entrance for the needle
about three-eighths of an inch to the right side of the mid-
line and a little caudalward from the tip of the spinous
process of one of the anterior lumbar vertebrae. The needle
is inserted by directing it slightly toward the mid-line and
a little in the direction of the head. If the needle hits the
spinal canal correctly some spinal fluid may escape. (It is
very desirable to have a needle which carries a plunger in-
side, i. e., a trocar and cannula to fit the hypodermic syringe.
In this case the plunger is withdrawn after the needle is in-
serted and fluid can flow out more readily.) When the
needle is inserted into the canal the barrel of the syringe is
picked up, any air which it may contain is expelled after
which the barrel is attached to the needle (which has been
left in place) and one cubic centimeter of novocaine solu-
tion is injected into the spinal canal. The needle is then
withdrawn and the opening may be covered with a drop of
collodion.

The animal is quickly untied and the muzzle is removed.
If the gas has been given properly and the dog was a suit-
able subject for this form of anesthesia (some dogs cannot
~be anesthetized well at all iritli gas) recovery from the N 2
should occur in a few minutes. Place the animal on the

360 EXPERIMENTAL PHARMACOLOGY

floor in a quiet place and watch it carefully. Is there any
disturbance of motion in the hind legs! If so does this ex-
tend to the fore legs also! After a few minutes test the
hind limbs for sensation and see if the animal feels pain 011
being pricked gently with a pin or stimulated with an in-
duced current, etc. Are there respiratory or cardiac dis-
turbances I Was the dose too large or too small ! Is there
any disturbance of heat or cold sensations in the hind
limbs?

Keep the animal under a close observation for several
days, watching particularly for signs of infection or men-
ingitis. How long does it take for the effects of the drug
to pass off? // signs of infection appear the animal must
at once be chloroformed.

On what structures within the spinal canal does the drug
act to produce the symptoms observed!

Could you demonstrate this action on a mixed (sensory
and motor) nerve in any of the peripheral nerves of the
body? If so how would you do the experiment I Would the
vagus he a suitable nerve?

EXPERIMENT XCIX.
Ergot. (Rooster: Action on Comb.)

1. A white Leghorn rooster should be selected for the
experiment. The rooster should not be fed for twenty-four
hours before the experiment is performed.

Examine the color, temperature and general appearance
of the comb and wattles. Then with a hypodermic syringe
inject deep into the breast muscles five cubic centimeters
of a fi.rst-class preparation of fluid extract of ergot
( Squibb 's is usually satisfactory). (The drug may also be
given into the crop with a soft rubber catheter.)

Place the animal in a quiet place and observe it carefully
from time to time for at least one or two hours. Do von

ACTION OF ERGOT 361

note any change in the appearance of the comb and wattles ?
If so at what time after the injection is the change at its
maximum? If you had a standardized preparation and a
non-standardized preparation of the fluid extract of ergot
could you compare the relative strengths of these two solu-
tions by their relative actions in the same sized doses on
roosters of approximately the same size, age, and sensitiv-
ity to the drug ? This is one of the methods sometimes used
to standardize ergot. (For literature, see Edmunds and
Hale : Bulletin No. 76, Hygiene Laboratory, U. S. Public
Health and Marine Hospital Service; also Pittenger: Bio-
chemic Drug Assay Methods, P. Blakiston's Son & Co.)

EXPERIMENT C.
Ergot. (Frog: Capillary Circulation.)

1. Take a thin board about four inches wide by seven or
eight long (a cigar box lid is very satisfactory) and cut a
hole about one inch in diameter in one end and near the side
as shown in Pig. 305. Fasten a frog, ventral side down-
ward, on the board as indicated with strings (except the
right hind leg). Draw the web of the right hind leg over
the hole in the board and fasten (with twine strings) the
toes in an extended position to spread the web out well.
Place the board on the stage of a microscope and examine
the capillary circulation in the web. Note carefully the size
and appearance of the capillaries and the rate of flow of
the corpuscles. Make a sketch to show what you see, ob-
serving especially the size of some of the vessels which you
see where they bear a certain relation to the pigment spots.
If the diameter of the arteriole changes can you detect the
variation by reference to the pigment spots ?

Under the skin of the back inject one-half cubic centi-
meter of fluid extract of ergot and watch the circulation
carefully from time to time as the drug is absorbed. Do
you get any change in caliber? If so how do you explain

362

EXPERIMENTAL PHARMACOLOGY

it? (Greene). Does the alcohol in the drug have anything
to do with your findings? Is the rate of movement of tiie
corpuscles affected?

Meanwhile observations mav be made on the retinal ves-

fastened
with strings

Fig. 305. Arrangement of apparatus for observing the capillary circulation in the web

of a frog's hind limb.

sels with the ophthalmoscope (room darkened). Do you
note any change here ? What conclusions can you draw ? A
second frog may be injected with alcohol (same strength as
that in the extract) and the results compared with those
from the ergot frog.

TYRAMIKE, ERGAMINE, ERGOTOXINE 363

EXPERIMENT CL
Tyramine. (Frog: Capillary Circulation.)

1. Repeat the above experiment on a fresh frog using a
solution of tyramine (parahydroxyphenylethylamine Bur-
roughs TVellcome and Co., New York). The solution may
be made up from the hypodermic tablets (one cubic centi-
meter equals four milligrams). Inject one cubic centimeter.
Repeat the observations and state your conclusions. AVhat
are the active principles found in ergot? (See Dale, Barger,
Laidlaw, Dixon: Journal of Physiology, xxxiv, xxxix, xli,
xliii ; Biochemical Journal, ii ; Archiv fur experimentelle
Pathologic und Pharmakologie, Ixi.)

EXPERIMENT CIL
Ergamine. (Turtle: Lung Tracing.)

1. Prepare a turtle to record a lung tracing. Take a nor-
mal and inject one cubic centimeter of ergamine solution
(five cubic centimeters equal one milligram) into the heart.
Record the results and discuss your conclusions in full.
Give different sized doses if necessar to et ood results.

EXPERIMENT GUI.

Ergotoxine, Ergamine, Adrenaline, Barium. (Dog or Cat:
Blood-pressure, Respiration, Uterine Contractions

Barbour's Method.)

1. Arrange a dog (or cat) for taking blood-pressure and
respiration tracings. Open the abdomen and gently move
the intestines upward toward the diaphragm. Expose the
uterine horns and ovaries. "\Vitli great care dissect the
ovaries loose from the underlying tissues and then gently
raise the two horns upward and slowly dissect loose the

364

EXPERIMENTAL PHARMACOLOGY

vessels and tissues holding the uterus down. Use the great-
est care not to injure the blood-vessels or nerves going to
the uterine horns both of which are brought together at the
upper ends. These ends are now tied with a thread which
is passed through a metal tube as shown in Fig. 306.

Petrolatum
\inuidum

Metal tube

Bifurcation of
uterus
Class tr metal
mnula In

Fig. 306. Arrangement of animal and apparatus for recording uterine contractions
according to the method of Barbour. (See Jour, of Pharm. and Exper. Therapeutics,
1915, vii, p. 547.)

The tube is lowered into the abdomen over (around) the
uterus, the two horns of which are pulled up as illustrated.
The tube is placed down in position (be sure the bladder
which should be empty is not caught inside the lower end
of the tube) and the abdomen is closed air tight with hemo-

RECORDING UTERINE CONTRACTIONS

365

stats. The tube is held in a large clamp attached to a stand.
The thread is brought upward over a very sensitive pulley
(one with jeweled bearings is preferred) about one inch in
diameter and thence is directed toward the drum where it
passes over another pulley and is then connected to a frog
heart lever which records the contractions.

Fig. 307. Tracing showing the action of barium chloride on the uterus, blood-pressure
and respiration in a dog. Tracing obtained by Barbour's method.

The injecting burettes contain adrenaline, ergamine and
ergotoxine phosphate. Ergotox'me phosphate is sold by
Burroughs, Wellcome & Co., New York and London. It is a
line brown powder (one gram vials, $7.00 or $8.00 ench) in-

366 EXPERIMENTAL PHARMACOLOGY

soluble in water and is dissolved as follows : Weigh out the
required amount, perhaps one hundred milligrams, and
place it in a dry beaker. Over the powder pour three or
four drops of ten per cent sodium hydrate solution and stir
the powder into the solution. Two or three drops of Avater
are slowly added from time to time as the drug goes into
solution. When all the powder is dissolved water is added
to bring the solution to the desired strength (one cubic
centimeter equals five milligrams). Since the drug is ex-
pensive it is sometimes advisable to make up only a small
amount and inject each dose directly into a vein (femoral or
external jugular) with a hypodermic syringe.

The metal tube in the abdomen is filled high enough to
cover the uterine horns with petrolatum liquidum (liquid
paraffin). This protects the uterus against cooling or dry-

ing.

When all adjustments are made arrange the writing-
points on the drum (slow speed) with the uterine record at
the top. Take a normal and determine what weight (ten-
sion) the uterus can best counteract. When all is ready
watch the pupils closely and inject two cubic centimeters of
ergotoxine (dog 7 or 8 kilos) and record the results. How
does the record compare with one made by adrenaline?
How long does the change in blood-pressure last ? Wait till
the drug has shown its action (perhaps four to six inches on
a slow drum). Did the uterus contract? How do you ex-
plain this! There is great variation in this respect in dif-
ferent animals and species. Inject one-half cubic centi-
meter of adrenaline. How does this drug act now as com-
pared with the result in a normal animal ? Do you note any
changes? (The size of tlie dose of ergotoxine is of im-
portance here more can be injected later.)

Get the animal into as good condition as possible and take
a normal. Watch the pupils and inject two cubic centi-
meters of ergamine (histamine Burroughs, Wellcome &
Co. put up in hypodermic tablets make solution ten cubic

ERGAMINE AND ADRENALINE

367

centimeters to one milligram) and record the results. Do
you get a contraction of the uterus? How is the blood-pres-
sure affected! The respiration? If the animal is about to
die inject one cubic centimeter of adrenaline and see how
this counteracts the respiratory and vascular actions of the
ergamine. Does this affect the uterus! In what ways may
the adrenaline act to change the respiration of this animal?
Wait a while and let the animal recover (if necessary).

VA+t.. .?

iumuuiuHmtv.(uiiuun

Fig. 308. Tracing showing the action of ergamine (histamine) and adrenaline on
the respiration (stethograph drum around chest) and blood-pressure in a dog. Ergamine
causes profound tetanic contraction of the bronchioles and shrinkage of the volume of
the lungs. This makes more difficult (and hence decreases) the normal respiratory
movements. This action may be accompanied by more or less depression of the respira-
tory center by the drug but the peripheral action is so powerful that it must be greatly
concerned in the decrease of the respiratory movements. Adrenaline (which dilates the
bronchioles) promptly relieves the respiratory embarrassment. Down stroke is .inspira-
tion. Does the animal have difficulty in inspiration or expiration? How does the
adrenaline affect this? How is the intrathoracic pressure affected?

368

EXPERIMENTAL PHARMACOLOGY

Were the records from the ergamine satisfactory? If so no
more of the drug need be given at present, but if the records
were poor (dose too small or too large) a second injection

Fig. 309. Tracing showing the action of ergamine (histamine) on the rate of oxygen
consumption, blrod-pressure and resuiraiion in a dog. The marked fall in blood-pressure
is not accompanied by a correspondingly great change in oxygen consumption.

may be given, the dose being estimated from the previous
results. Let the animal recover (giving one-half cubic
centimeter of adrenaline if necessary).

ERGAM1NE, ADRENALINE, TYRAMINE 369

Now inject cautiously in small repeated doses several
cubic centimeters of ergotoxine. How is the blood-pressure
affected? Examine the pupils from time to time and note
any change. Stimulate one vagus nerve and observe the
effect on the corresponding pupil and the heart. Does the
blcod-pressure fall to a low level and remain there? Does
the ergotoxine now fail to raise the blood-pressure (in the
same sized dose as that first given) ? Get the animal into as
gocd condition as possible and inject one cubic centimeter
cf adrenaline. Do you get a marked rise in blood-pressure'?
Does the uterus react? Was the dose large enough? Ex-
plain your results in detail. What structures have been in-
volved and how are they affected? Do your results cor-
respond with those described in the literature?

Empty out the ergamine, fill the burette with one-half per
cent barium chloride and inject five cubic centimeters (dog).
Do you get a rise in blood-pressure or a contraction of the
uterus? On what structures does the barium act? Have
these been affected by the other drugs!

Kill the animal with barium. After death dissect out the
thoracic duct in the neck and place a thread around it. (See
Figs. 302 and 319.) Also dissect out the left pulmonary
artery (Figs. 274, 275, 276, and 277).

EXPERIMENT CIV.

Ergamine, Adrenaline, Tyramine, (Codeine or Heroine).
(Dog: Blood-pressure, Pulmonary Blood-pressure,

Respiration.)

1. The dog should weigh at least eight or ten kiloG. It is
advisable to give a small dose of chloretone. Arrange for
recording blood-pressure and set up the two manometers
(one for the pulmonary pressure) as shown in Fig. 273.
Read over the directions for Experiment LXXVII, p. 310,
carefully, and prepare to follow out the technic given there

370

EXPERIMENTAL PHARMACOLOGY

RECORDING PULMONARY BLOOD-PRESSURE 371

for recording pulmonary blood-pressure. In this present
experiment, however, arrange first to take a record of the
action of tyramine. Record the blood-pressure (carotid)
and the respiration (stethograph).

Tyramine is sold in the form of hypodermic tablets (0.020
gram % gram each) by Burroughs, Wellcome & Co. Make
a solution containing five milligrams to one cubic centi-
meter. (It may be advisable to inject this with a hypo-
dermic syringe into the external jugular or femoral vein
to avoid using more drug than is necessary.)

Adjust the writing points on the drum, take a normal
record and inject one cubic centimeter. You should get a
rise in pressure which persists for some time. Wait for the
effects of this to wear off and save your animal as it will
need all the vitality it has for the next part of the experi-
ment. On what structures does tyramine act? To what
other drug is it most similar in action! How does it differ
from ergotoxine?

Remove the stethograph and insert a cannula (see Fig.
279) into the left pulmonary artery. The injecting burettes
(femoral veins) contain ergamine (ten cubic centimeters
equal one milligram, see Experiment CII) and adrenaline
(1:10,000). Be sure the artificial respiration is being car-
ried out satisfactorily and that the animal does not get too
much (nor too little) ether.

Adjust the writing points, take a normal and inject one-
half cubic centimeter of adrenaline. Is your adrenaline
preparation satisfactory? (Many samples are spoiled be-
fore the bottles are opened and an exposed solution rapidly
deteriorates.) (See Fig. 311.)

When the records return to normal watcli the lungs
closely and inject two cubic centimeters of ergamine solu-
tion (or less if the animal is small) and record the results.
How is the carotid pressure affected? Did you see any
change in the relative extent of expansion and contraction
of the lungs with each inflation from the respiration ma-

372

EXPERIMENTAL PHARMACOLOGY

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EEGAMINE, HOEDENIXE, ATEOPINE 373

chine! If your drug was pure and the dose suited to the
dog you should see the lung changes. To what do these cor-
respond f Was the pulmonary blood-pressure affected!
HOW T was this brought about? What structures were in-
volved and how were they affected! (See Cloetta: Archiv
fur experimentelle Pathologie und Pharmakologie, 1914).
What relation does a dilatation of the bronchioles bear to
the pulmonary pressure ! What relation does a contraction
of the bronchioles bear to the pulmonary pressure !

If the animal is still in a fair condition give it a dose of
adrenaline and change the ergamine solution for one of
codeine or heroine (one cubic centimeter equals five milli-
grams). You must work quickly for the animal may die at
any time. Inject five cubic centimeters of the codeine (or
heroine) solution (watch tlie lungs] and compare the pul-
monary reaction here with that under ergamine.

Kill the dog with one of your solutions. Make a diagram
showing the complete innervation of the lungs.

EXPERIMENT CV.

Ergamine, Adrenaline (or Hordenine), Atropine. (Spinal
Dog, or Cat: Bronchioles.)

(Bladder contractions may also be recorded if desired.)

1. A number of methods have previously been described
for recording bronchial contractions. With positive arti-
ficial respiration in a spinal dog a perforated brass tube can
be passed through the chest, or by use of the lung shield
(Fig. 200) a bent glass tube can be inserted through the
right chest wall to record changes in the right lung only, or
by use of the special forms of apparatus shown in Figs.
255 and 256 the entire chest cavity can be used as a ple-
thysmograph frcm which a tube is led off to the large bowled
recording tambour (Figs. 14 and 372). With the negative
pressure method of carrying out artificial respiration by
means of aspirating the chest cavity after one or the other

374 EXPERIMENTAL PHARMACOLOGY

of the special pieces of apparatus shown in Figs. 255 and
256 have been inserted into the chest the best results can
be obtained. The writer recommends that all laboratories
which can afford it build some such form of universal arti-
ficial respiration machine as those shown in Figs. 360 and
364 or that where both positive and negative air pressure is
already available to the laboratory a universal valve like
those shown in Figs. 365 and 366 be obtained. Cats can be
used very well for lung tracings by the aspiration method,
in fact in some respects they are better than dogs, but the
larger size and greater vitality of dogs make them prefer-
able as a rule.

By one of the methods previously given arrange to take
a record of the bronchial muscle changes and to record the
right carotid blood-pressure. The arrangements for re-
cording blood-pressure should be completed first. The in-
jecting cannulas are next inserted and the burettes are filled
with ergamine solution (ten cubic centimeters equal one
milligram) and with adrenaline (1:10,000) or hordenine
(one cubic centimeter equals ten milligrams this can be
bought of Burroughs, Wellcome & Co. 1 gram $1.80, solu-
ble in water on heating).

The chest is now opened (if this method is to be used)
and the apparatus is inserted (using positive artificial res-
piration). Two courses are now open as follows: 1st, If
positive artificial respiration (a hand bellows may be used
if nothing else is obtainable) must be used throughout the
experiment the tambour tube is now connected to the ap-
paratus in the chest and a record about three inches in am-
plitude on the drum should be arranged for by making the
proper magnification for the writing point, regulation of
the expansion of the lungs, etc. If one has a well-fitting
piece of apparatus in the chest he need not necessarily pith
the dog by this method but it is usually advisable to do so
to keep the animal quiet and to avoid the anesthetic. 2nd,
If negative artificial respiration can be used, then after the

BRONCHIAL TRACINGS 375

apparatus is fully adjusted in the chest the animal is pithed
and the recording tambour is attached to the straight end
of the tracheal cannula, the side tube of the canimla having
a short rubber tube with an adjusting screw clamp (Hof-
mann's) attached to it. The ether is removed as a spinal
animal needs no further anesthetic at all. Pithing is car-
ried out by trephining the skull and destroying the brain
and upper part of the cord as described and illustrated in
Experiment LXX, page 292. (Experiment LXX should be
read over before this one is started as the technic is the
same in each and the figures given there will be needed for
the present experiment.)

After the dog is pithed the head is returned to its former
position and the shift from positive to negative artificial
respiration is made. The recording tambour is attached
(by a glass reducer) to the short piece of three-eighths inch
rubber tubing on the straight end of the tracheal cannula
and the large boiuled tambour is adjusted to give a record
of about three inches in amplitude placed just above the
blood-pressure (which should be about three-fourths to one
inch above the base line). Inspiration corresponds to the
downstroke of the tambour.

When all adjustments are made take three-fourths or one
inch of normal record (be sure everything is working all
right otherwise readjust the apparatus). Now with care
stimulate each or both vagus nerves and determine exactly
what influence these have on the bronchioles. What con-
clusions can you draw? Explain in detail. Take another
normal and then inject one cubic centimeter (dog) of er-
gamine solution. You should get an immediate response.
If you do not the dose may have been too small (possibly de-
teriorated drug but this is rare) and you can let the animal
recover and then give a larger dose. The right sized dose
will give a profound bronchoconstriction. When this is at
its maximum inject one-half cubic centimeter of adrenaline
(or four cubic centimeters of hordenine solution) and note

376

EXPERIMENTAL PHARMACOLOGY

the results. (See Fig. 312.) AYhat structures are involved
and how are they affected ?

As soon as you get one good tracing from the ergamine
then empty it out and nil the burette (or connect a third

Fig. 312. Tracing showing the action of ergamine (histamine. /3-iminazolylethylamine)
and hordenine on the bronchioles and blood-pressure in a spinal dog. Curara had been
given.

burette to an external jugular vein) with atropine solution
(one cubic centimeter equals one milligram). Start the
drum and inject one cubic centimeter of the atropine. Then
stimulate the vagus nerves and see if the bronchioles or

BRONCHIOLE TRACINGS

377

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378

EXPERIMENTAL PHARMACOLOGY

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BRONCHIOLE TRACINGS

379

heart respond. AVhat conclusions can you draw from this .'
Replace the ergamine into the burette (if it was emptied out
before) and take a normal record. Inject a dose of er-
gamine (gauge the size by your previous experience the
dose should be a little larger than that which was previously
just sufficient to produce a maximum effect, for the animal
becomes a little less sensitive all the time to the drugs).

Fig. 315. Tracing showing the action of arecoline, ergotoxine. (arecoline) and adrenaline
on the bronchioles and blood-pressure in a pithed dog.

380 EXPERIMENTAL PHARMACOLOGY

Do you get a satisfactory record? Has the atropine
changed the influence of the drug on the bronchioles ? What
does this prove! How does the action of hordenine com-
pare with that of adrenaline?

If the animal is still in a suitable condition (which is im-
probable) you may try to get another contraction of the
bronchioles from ergamine and then follow this with an in-
jection of tyramine. This drug is described as acting in
many respects like adrenaline. Will it dilate the bron-
chioles ? Stop the artificial respiration and kill the animal.
Disseet out both eyes and preserve them in fifty per cent
alcohol (or ten per cent formalin) for dissection later.

EXPERIMENT CVI.

Ergotoxine, Ergamine. (Cat, Guinea Pig, Dog, Rabbit:

Uterine Strip.)

1. From one of the animals mentioned prepare a uterine
strip and arrange to record its contractions as illustrated in
Fig. 292 (or as in Fig. 316 if you have the apparatus). The
drum should have a very slow speed.

When all is ready take a normal record and see if you can
determine whether or not the muscle is in a strong tonus,
and if it is properly weighted. A good deal of experience
is required to get the best results from the strips. Add one
or two cubic centimeters of ergotoxine solution (one cubic
centimeter equals five milligrams) to the salt solution in
which the strip is suspended. Do you get a contraction? If
not add some more drug. Wait and see what happens.
What conclusions can you draw ?

After a time change the salt solution and allow the strip
to record a normal contraction. Do you need to change the
weight? Now add two cubic centimeters of ergamine (five
cubic centimeters equal one milligram) to the salt solution.
What do you observe ? Is it necessary to add more erga-

UTERINE STRIP CONTRACTIONS

381

mine? What conclusions can yon draw? Change the salt
solution and then see if you can get a contraction of the
strip by adding barium chloride (in one- half per cent solu-
tion) to the beaker. On what structures does each of these
drugs act?

Air. vent

JfOCK
solution

water
bath

Bull dog
(Adjustable
weight]

Metal waterbath

38c.

Harvard muscle
warmer with
raduated scale

in. metal
heating rod
soldered in
wall of

water bath

Fig. 316. Arrangement of apparatus for recording contractions of a uterine strip,
intestinal strip, or ring, etc. The metal water bath is made of a cheap metal water pail
with a heating rod soldered through the side at the bottom. A short metal tube is
soldered into a 1-mch opening in the bottom to receive a perforated cork for connecting
with the Harvard muscle warmer inside.

EXPERIMENT CVII.
Ergot. (Cat: Action on Uterus.)

1. Secure a gravid cat as near full term as possible. Un-
der the skin of the back inject with a hypodermic syringe
two cubic centimeters of a good fluid extract of ergot. Put
the animal in a quiet place and observe it carefully from
time to time for several hours following. Discuss your con-
clusions in detail.

382

EXPERIMENTAL PHARMACOLOGY

EXPERIMENT CVIII.

Pituitrin, Ergamine, Adrenaline. (Dog, Cat, or Rabbit:
Uterine Contractions, Blood-pressure.)

1. Cats are preferred for the experiment. Observe care-
fully the arrangement of the animal and the apparatus

-Burette in
extjuguldr vein

Burette in
femoral vein

Bun sen i^
burner

Tube to
artificial

respiration
machine

Fig. 317. Arrangement of apparatus for recording contractions of the uterus in situ.
(The experiment is difficult and often yields unsatisfactory results.) A somewhat similar
arrangement may be used for recording intestinal contractions.

shown in Fig. 317. The animal is given .3 to .4 gram per
kilogram of body weight of ehloretone (dissolved in alcohol)
by stomach tube. Artificial respiration may be given
throughout the experiment. Arrangements are made for
recording the blood-pressure (omit this if sufficient appara-
tus is not available), and injecting cannulas are connected
with one femoral vein and one external jugular. These con-

UTERINE CONTRACTIONS 383

tain ergamine (ten cubic centimeters equal one milligram)
and pituitrin (one cubic centimeter to five cubic centimeters
of water Parke, Davis & Company's preparation is usually
satisfactory, but several other extracts are on the market).

The metal box in which the animal is placed is now filled
with 0.9 per cent salt solution which is thereafter kept at
39 C. by a bunsen burner. This prevents exposure of the
viscera to the cold air and avoids drying of the tissues.

The abdomen is now opened by a long median incision
and the intestines and bladder are pulled gently to one side
and fastened beneath the salt solution, thus exposing the
uterine horns. One of these is followed up to the ovary
which is gently dissected loose from its attachments (using
great care not to disturb the blood-vessels) and the distal
end of the uterine horn may also be freed a little from the
body wall to permit freedom for its movements if contrac-
tions occur. A myocardiograph (Cushny's, Wigger's, etc.,
or Fig. 141 ) is now placed down over the abdomen. A small
round needle is used to pass two stitches of fine thread
through the uterine horn about one inch apart. These
stitches are used to attach the levers of the myocardiograph
to the uterine horn. A very light recording lever (heart
lever or light muscle lever) is attached to the myocardio-
graph and arranged to write on the drum above (and
slightly to the left of) the blood-pressure record. The lever
is weighted as nearly as can be estimated to suit the
strength and tone of each uterine horn.

When all adjustments are made a normal record is taken
and then one-half cubic centimeter (for a full grown cat)
of the pituitary solution is injected. Do you get a rise in
blood-pressure? You should do so and this rise lasts for a
considerable time. Wait for the curve (blood-pressure) to
come back to normal. (Inject a larger dose if necessary to
get a good record.) Did you get a uterine contraction?
What explanation can you offer? Does this have any clini-
cal significance?

334 EXPERIMENTAL PHARMACOLOGY

Now inject one-half cubic centimeter of ergamine (cat)
and see what effect this has. Do you get a fall in blood-
pressure? Will the animal be likely to die! (If so, give it
a small dose of pituitrin.) Did the uterus contract? If so
en what tissues did the drug act and how were they affected?
Wait a while for the animal to recover and observe any later
actions of the drug. After a time more ergamine may be
injected to get another record.

If the animal is still in suitable condition adrenaline solu-
tion may be substituted for one of the solutions in the bu-
rette and a dose of this drug injected. How does the action
of adrenaline on the uterus compare with that of the other
drugs given? What is the innervation of the uterus? (See
Fig. 318.) Kill the animal by giving a large dose of one of
the drugs you have. What can you say about changes in the
innervation of the gravid uterus in the cat ? Does this hold
also in the human uterus? Can you find this point in the
literature?

This method of recording uterine contractions is some-
times used to standardize ergot preparations by comparing
the strength of the unknown solution with that of a standard
preparation. (For literature, see Edmunds and Hale: loc.
cit.; Dale, Dixon, Laidlaw, Barger: loc. eit., p. 363; Pitten-
ger, P. S. : Biochemic Drug Assay Methods, P. Blakiston's
Son & Co.; also Dale: Biochemical Journal, iv, p. 427.)

EXPERIMENT CIX.

Pituitrin, Ergamine, Levulose, Adrenaline. (Dog: Thoracic

Duct, Blood-pressure, Bladder Contractions,

Respiration.)

(Give the dog one-half pint of cream to drink three hours

before the experiment.)

1. Arrange a dog for recording blood-pressure, respira-
tion and bladder contractions. Do not disturb the viscera

\P//o motor muscle
Lachryma/q/and

Nasalmucosa

Sublingual
gland

Submaxillary gland

Submaxilldry(5ublingual)
ganglion

Call bladder and
ducts

Cranial and Sacral nerves

motor ^ red

inhibitory = blue
Thoracico-lumbar nerves

inhibitory Careen
'Postganglionic fibers
are dotted, thus

N.XI

Sup. cervical ganglion

Thyroid gland

N.K
Chordo-tymp.n. /

Small intest.
Pancreas

Iliocecal
sphincter

B/aBde
Vesical sphin
Urethra I sphincter,

Pelvi

subclavia

SteJIate (i s J- Thoracic)
ganglion

Sweat gland

motor
fibers

Pilo motor muscle

p-

Celiac (Semilunar)
ganqlion(Solarplex)

Splanchnic nerves
_- Sympathetic chain

[ Lumbar splanchnics

Sup. Mesenteric

ganglion

Inf. Mesenteric
ganglion

hypogastric nerves

7? P haileck.

^, Tl ^,,ypoga5tric,iiwsriliac) ( sphincter , v

plexus. (Yesicals, rectal portions) Pelvic nerves (Nervus erigens)

Fig. 318. Schematic representation of the involuntary nervous system.

ext jugular vein

subclavian vein
Thoracic duct

Sterno-mastoid
muscle

Sterno

masfoid

muscle

. int. jugular vein
Vagi nerves

Carotid arteries

To ether bottle

To manometer

Fig. 319. Dissection showing the method of isolating the thoracic duct at the root of
the neck. Care should be taken not to perforate the parietal pleura at the apex of the
chest if it can be avoided in making the dissection.

KATE OF LYMPH FLOW I" IS.")

any more than can be helped in putting in the bladder can-
nula. Clamp the penis or vulva with a hemostat to prevent
urination.

Consult Figs. 319 and 302 and dissect out the thoracic
duct. Place a cannula in it and collect the lymph as it drops
from the small rubber tube placed on the cannula. The
cannula must be very small, the opening in the end should
be about the size of a very small thread and the outside of
the tip of the cannula should not exceed %2 or %4 of an inch
in diameter. Try to avoid penetrating the chest cavity at
the apex in dissecting out the duct. If the chest is opened it
may be necessary to give artificial respiration during the
rest of the experiment. If the cream has reached the in-
testine and is being absorbed well (two to three hours after
meal) the thoracic duct in the neck should be of a whitish or
yellowish-white color and in an average sized dog will be
about y 1(! or % 2 of an inch in diameter. The duct is com-
posed of exceedingly thin and delicate tissue and can be
easily torn off and, lost in the dissection, the student per-
haps not seeing it at all at any time. A little pressure will
compress the duct and check all out-flow from it.

(Those students who have sufficient technical skill may
also insert a cannula in the lymphatic duct coming from the
head and collect lymph from both ducts at the same time.
There is a very marked difference and the experiment is
well worth doing.)

The injecting burettes contain pituitrin (1 to 5 Parke,
Davis & Co.), ergamine (ten cubic centimeters equal one
milligram) and adrenaline (1:10,000).

When all adjustments are made take a normal tracing,
watch the pupils and inject one cubic centimeter of pituitrin
solution (dog, eight kilos or more). Do you get a rise in
pressure, contraction of the bladder and a change 'in the
rate and depth of respiration? If the dose was sufficient, as
it probably was, alloAv the animal to return to normal and
wait until the normal rate of lymph flow is determined

386

EXPERIMENTAL PHARMACOLOGY

(number of drops per minute). The rubber tube or cannula
may become clogged. If so pass a stiff twine string down
the cannula and try to remove the clot.

The pituitrin is now emptied out and the burette is filled

-Superficial lymphatics from head
Submaxillary lymph glands

Laryngeal glands

Trachea! trunks
Cervical glands

^ lymphatics from limb

External
jugular vein

Precava
Axillary glared

Bronchial glands
receiving lymph
lungs

Lymphatic vessels
from liver

Small
intestine

from

^-Junction of thoracic duct with

trachea! trunk
Sabdavidn vein

Lymphatic trunk
ee/> lymphatic vessels from limb

Lymphatics from thoracic wall

Vessel from diaphragm
Thoracic duct

Pancreas Aselli

Lymph trunk from pancreas Aselli
to thoracic duct

Receptaculum chyli

Lacteal vessels and glands of

mesentery

Lumbar glands

Iliac glands

vessel from ^hjl ft ^V^yesse/s from limb
abdominal ^//<^/7U^v

Inguinal glanas / "" ^Lymphatics from skin of leg

Ha I leek

Large intestine

Fig. 320. Diagrammatic representation of the lymphatic system in a cat. (Partially

adopted from DavisonJ

LYMPH FLOW PITUITEIN 387

with levnlose solution (five or ten per cent). In small re-
peated doses (one-half or one cubic centimeter) several
cubic centimeters of the levulose solution are injected. Wait
then and see how the rate of lymph flow is affected. (How
is the lymph flow from the head affected? Is this rate of
flow maintained or does it decrease after a time!)

After some time note the rate of lymph flow and adjust
all writing points. Observe the pupils and inject one cubic
centimeter of ergamine. Do you get satisfactory records?
If the dose was too small wait a while and inject a larger
one to get good results. How did the bladder respond?
How does this compare with pituitrin?

Inject adrenaline and see how this affects the lymph flow,
bladder, pupil and respiration.

With what other lymphogogues are you acquainted ? You
may try some of these on the animal if it is still in suitable
condition. Kill the animal with an injection of some of the
drugs you have. Always get a death record in such cases
and see which stops first, the heart or the respiration.

How may drugs affect the rate of secretion or of flow of
lymph? How is the formation of lymph controlled? What
can you say about the innervation of the lymphatics ? HOAV
does atropine affect lymph secretion?

EXPERIMENT CX.

Pituitrin. (Frog: Capillary Circulation.)

1. As in Experiment C, page 361, arrange a frog for ob-
serving the capillary circulation in the web of the foot (Fig.
305). Observe carefully (for comparison) the normal rate
of capillary flow and then inject one-half cubic centimeter
(or more) of pituitrin under the skin of the frog's back.
From moment to moment again observe the circulation in
the web and see if any change occurs. If you note a change
keep a careful watch on the animal from time to time for

388

EXPERIMENTAL PHARMACOLOGY

two or three hours and see if there is a return to normal.
Keep the animal covered with a thin layer of wet cotton.

EXPERIMENT CXI.

Pituitrin. (Frog or Turtle: Heart Tracing.)

1. Pith a frog or turtle and take a normal heart tracing-
showing vagus inhibition. Irrigate the heart with some
pituitrin solution (1 to 5) and determine the action of the
substance on the heart. Is the inhibitory apparatus in-
volved in any way ? How is the musculature of the heart af-
fected?

EXPERIMENT CXII.

Pituitrin. (Turtle: Lung Tracing.)

1. Arrange a turtle for recording lung tracings. Stimu-
late one vagus nerve and see if you get a contraction of the

Fig. 321. Turtle lung tracing showing the action of pituitrin.

lung. The magnification of the tambour tracing should be
large. Take a normal and inject into the heart one cubic
centimeter of pituitrin solution (1 to 5). AVhat conclusions
can vou draw from vour results?

ACTION OF PITUITRIN

389

Fig. 322. Tracing showing the action of pituitrin on the uterine contractions and blood-
pressure in a dog. Made by Barbotir's method.

390 EXPERIMENTAL PHARMACOLOGY

EXPERIMENT CXIII.
Pituitrin. (Guinea Pig, Cat, Dog, Rabbit: Uterine Strip.)

1. Cats or guinea pigs are preferred. Prepare a uterine
strip and record its contractions. (See Experiment CV1,
also Figs. 292 and 316.) After the strip is properly
weighted and a short record has been taken add to the solu-
tion surrounding the strip one cubic centimeter of pituitrin
(1 to 20). Do you get a satisfactory contraction! Wait a
while, the drum runs at a very slow speed. If after some
minutes no change has been produced replace the salt solu-
tion with a fresh supply and inject a larger dose of pituitrin.
Could you standardize the size of the dose by the size of
the contraction the uterine strip gives :' If you had a
standard preparation of pituitary extract could you coin-
pare with this the strength of an unknown sample? If one-
half as large a dose of the unknown sample were required to
give a tracing three inches high, as was required of the
standard preparation, what could you say of the relative
strengths of the two samples? How much would you dilute
the unknown preparation to bring it to the same strength
as the standard? This is essentially the method commonly
used to standardize (assay) pituitary preparations for the
market. (For literature, see Dale and Laidlaw: Journal
of Physiology, 1910-11, xli, p. 318; Dale and Dixon: ibid,
1909, xxxix, p. 25; Dale and Laidlaw: Journal of Pharma-
cology and Experimental Therapeutics, 1912, iv. p. 75:
Hamilton, H. C. : Journal American Pharmaceutical Asso-
ciation, 1912 ; Roth, G. "\V. : Bulletin Hygiene Laboratory,
No. 100; also Journal Pharmacology and Experimental
Therapeutics, 1914, v. p. 557; Fenger: Journal Biologic
Chemistry, 1916, xxv, p. 417; Frankl-Hochwart und Froh-
lich: Archiv fur experimentelle Pathologie und Pharma-
kologie, 1910, Ixiii, p. 347 ; Hamilton and Rowe : Journal of
Laboratory and Clinical Medicine, 1916, ii, p. 120.)

PITUITRIX, ADREXALIXE, ATROPIXE

391

EXPERIMENT CXIV.

Pituitary Extract, Adrenaline, Atropine, Barium. (Dog:

Bronchial Contraction.)

1. By one of the methods previously used arrange a dog
for recording bronchial contractions. When all adjust-
ments are made stimulate the vagus nerves and see how the

Fig. 323. Tracing showing the action of pituitrin on the bronchioles and blood-pressure

in a spinal dog.

bronchioles react, then inject two cubic centimeters (dog-
eight to ten kilos) of pituitrin solution (1 to 5). Do you
get a satisfactory record"? What is the action of pituitary
extract on the bronchioles? Is this a muscular or nervous
affair? "What action has pituitrin on the sympathetic
nervous system? How does this compare with adrenaline
and tvramine?

392 EXPERIMENTAL PHARMACOLOGY

This dose was probably large enough (for some animals
too large the instructor may advise you about this) but
if you think advisable try another dose to see if you can
get more satisfactory results.

When the animal recovers give one cubic centimeter of
atropine, then stimulate the vagi and see if the heart is
inhibited (how are the bronchi affected?). Give a little
adrenaline to revive the animal and inject another dose
(estimate the size) of pituitrin. How are the bronchioles
affected now after the atropine? Would you advise the
use of pituitrin in bronchial asthma ! How do your results
in this experiment compare with those obtained on the
turtle lung ? Kill the animal with a large dose of barium
chloride solution (one-half per cent). How does this affect
the bronchi ?

EXPERIMENT CXV.

Pituitrin, Adrenaline, Aconitine. (Dog: Urine Secretion,

Intestinal Contractions, Blood-pressure, and

Respiration.)

1. Arrange a dog for recording the blood-pressure, res-
piration and intestinal contractions (by the fingercot-bu-
rette method). The injecting burettes contain pituitrin (1
to 5) and adrenaline (1:10,000). Carefully isolate both
ureters (Fig. 162) and place a ureteral cannula (Fig. 213)
in each. Arrange the cannulas to collect the urine Mow
in a beaker. Record on the drum the rate of drop Mow with
a signal magnet (worked by a simple key in circuit with a
dry cell). Close the abdomen with hemostats and wait ten
or twenty minutes to get the normal rate of urine Mow.
(The drum should have a very slow speed.)

When the normal rate of urine Mow has been determined
(if no urine is excreted after twenty minutes go on with the
experiment and watch for the Mow to begin), take a nor-
mal record and then inject one cubic centimeter (for eight

PITUITEIN AND ACOXIT1NE 393

to ten kilo dog) of pituitrin solution. How does this affect
the blood-pressure? What happens to the respiration 1 ?
Is this a central or a peripheral action? After the records
return to normal (see that all pointers are recording
properly) inject a second dose of one cubic centimeter and
compare the results produced by this with those obtained
from the first injection. As soon as the records again reach
the normal (keep the anesthesia regular) inject a third dose
of one cubic centimeter. Does the animal become more or
less sensitive to the drug! Is the rate of urine flow affected
in any way ! If so how do you explain it ? Is the change
as great as you expected? How does it compare with caf-
feine or sodium sulphate ? Conthme giving pituitrin until
five or six (or more) cubic centimeters have been given,
watching for changes in the rate of urine flow in the mean-
time. Do the intestines show any signs of increased ac-
tivity! If so is this a nervous or muscular affair? Inject
some adrenaline and see how this affects the urine flow and
intestinal records. Do you see any signs of a tolerance
being developed for the pituitrin? If so to what is it due . ;
Does this occur with any other drugs '! Could you stand-
ardize an unknown pituitary extract by comparing the ac-
tion of various sized doses of the unknown with a standard
dose of a standard pituitary extract on the blood-pressure ?
This method is sometimes used to assay pituitary extracts.
In that case small sized doses are given and a considerable
period of time (fifteen minutes or more) is allowed to elapse
between each two injections.

If the animal is still in fair condition place a solution of
aconitine "potent' 1 (ten cubic centimeters equal one iniUi-
f/r(U)i) in the burette and determine what is the very least
amount of the substance required to kill the animal. The
injections must be made cautiously. Watch for postmortem
intestinal contractions. Open the chest and see if the heart
is fibrillating.

394 EXPERIMENTAL PHARMACOLOGY

EXPERIMENT CXVI.

Pituitrin, Adrenaline, Vanadium. (Dog: Pulmonary

Blood-pressure.)

1. In the manner described in Experiment CIV, p. 369
(also in Experiment LXXVII, p. 310) arrange a dog for
recording pulmonary blood-pressure. The injecting bu-
rettes contain pituitrin (1 to 5) and adrenaline (1:10,000).
When all adjustments are made take a normal record and
then inject one cubic centimeter pituitrin solution. Do you
get a change in pulmonary pressure? Would you advise
the use of pituitary extract in a pulmonary hemorrhage
from a tuberculous lesion ? What structures are affected
by the drug in the lungs! Would the drug be advisable in
bronchial asthma?

After a rec-ord showing the action of pituitrin on the pul-
monary pressure has been obtained get the animal into as
good condition as possible and fill one burette with a solu-
tion of sodium orthovanadate (two per cent when the drug
is dissolved in the water the solution is slightly alkaline).
Add a very small amount of hydrochloric acid to neutralize
the alkalinity. A bright, clear, orange-yellow solution will
be produced. Take a normal record and inject two cubic
centimeters of the vanadium solution. Was the dose large
enough? If not, possibly you can still get another record
with a larger dose. Kill the animal with the vanadium
solution. What conclusions can you draw from the experi-
ment? On what structures does the vanadium act?

EXPERIMENT CXVII*
Dissection of the Eye. Its Anatomy and Pharmacology.

Consult Figs. 324 and 325. It is advisable to read the
ction on
anatomy.

section on the anatomy of the eye in some good text-book on

*It is expected that this experiment may be performed on a day when no other experi-
mental material is available.

iridis

Pupil

Radial
(dilator)
muscle
of iris

To ciliary muscle
ciliary muscle

Dilatation
of pupil

Contraction
of pupil

Hill

Ciliary muscle (accommodation)
N.Ill (Contraction of pupil)

''/j-Efecfroc/es

(Dilatation or constriction of pupil;
contraction of ciliary muscle)

Electrodes
(Dilatation of pupil,
opening wider of eyelids, or
bulging forward of eyeball)

Out-going sympathetic rami communicants/

Sensory ganglion cell
(Sensory nervesfrom eye region)

mm ' * Nucleus of-

origin M nerve

Corpora

' o.uadrigemina

Position^) of
pupillo-dilator
center

N.VII

N.VIII

N.V1

Medulla
oblongata

Descending symp-
athetic fibres

in the

-Spinal cord
(sp.-medulla)

Cat, dog, rabbit

I Thoracic

n

W

Long ciliary '/'

nerves ,,,

'Paths

ofN.I

Short ciliary
nerves

Jemilunar

(Gasserian)
ganglion

Opthalmic division

v lint, carotid art's plex.

Radix longus

Sup. cervical
ganglion

Fig. 324. Schematic representation of" the innervation of the eye. Postganglionic fibers

are shown as broken lines.

Endings of N.V (Sensory) in

Endings of N. Ill in
sphincter pupillae muscle
Sinus venosus sclerae '
(CandlofSchlemm)

5patia anguli
iridis

(Spaces of
Fontana)

Sneafh of optic
nerve

Arteria centra I is
retinae

Sensory fiber from N.V
to the eye regions

Postganglionic fibers
are dotted thus

7^o

tissues of the eye

Cornea

Anterior chamber (Aqueous humor)
Posterior chamber

Ending of sympathetic fiber in
dilator pupillae muscle
Ending of N. Ill in ciliary

muscle
Suspensory ligament

of the lens
-Tendon of rectus
muscle

Retina
Choroid
clera

Fovea cenfralis

Cilidry ganglion

Fiber to ciliary muscle (Accommodation)
Fiber to sphincter pupillae muscle

Sup. cervical ganglion
/a Cerv. symp.
B cord

Post gang. symp. fiber to dilator pupillae

muscle

Fig. 325. Diagrammatic representation of the structure and innervation of the eye.

ANATOMY AND PHARMACOLOGY OF EYE 395

The eyes saved previously from dogs may be used for
dissection, or eyes from hogs or cattle may be secured (in
weak formalin solution) from the slaughter house.

Dissect away the fascia from the outside of the eye-ball
and isolate and identify the extrinsic muscles. Are there
any variations in these in different species of animals!
What is the innervation of these muscles"?

Isolate the optic nerve and follow it to the sclera. Dis-
sect off the extrinsic muscles and free the eye from fascia.
Do you have a right or a left eye? Locate on the eye-ball a
point directly outside the area which should be occupied by
the fovea centralis. Do the lower animals possess this
structure? What is its function? Over this area cut a win-
dow about one-eighth inch square in the sclerotic down to
the choroid. Hunt for the fibers of the ciliary nerves which
pass forward in the interspace between the sclera and the
choroid. In the normal animal what reactions would fol-
low electrical stimulation of these fibers? With care en-
large the opening in the sclerotic a little and then dissect
away the choroid which forms the floor of the opening.

Use great care not to penetrate the retina which will be
exposed when the choroid is removed. If the eye has not
been long in the formaldehyde or alcohol the cornea and
lens may still be transparent enough to allow an image to
be formed on the retina (this is best shown in fresh eyes).

Take a sheet of brown wrapping paper a foot square and
roll it into a tube with an opening just large enough to hold
the eye at one end. Place two rubber bands around the
tube to prevent unrolling. The eye is placed in the end of
the tube with the opening in the sclerotic and choroid coats
turned outward, i.e., the cornea and lens are directed to
look through the tube. Point the open end of the tube to-
ward an incandescent light or bright window and watch
carefully in the exposed area at the back of the eye for an
image of the light or window. If you detect any image
state fully its characteristics and peculiarities.

396 EXPERIMENTAL PHARMACOLOGY

Examine the cornea and pupil. Place the eye in a pan of
water and make an incision around it in the line of the
equator so as to separate the front half from the rear half.
The incision may go through all three coats, but the vitre-
ous humor should not be disturbed. Lift off the rear half
of the coats and look into the cup thus formed. What color
is the retina? Of what is it composed ? What drugs act on
the structural elements of the retina ? AVliat particular
parts of the retina are involved in this action ? Define the
optic disc and the central artery of the retina. AVliat is
meant by the optic cup? AVliat relation does it bear to the
macula lutea ? Separate the sclerotic from the choroid and
define the lamina fusca. Hunt for the ciliary nerves (and
vessels) between the sclera and choroid. How do these
nerves get into the eye-ball ? Define the lamina cribrosa
sclerse.

Now take up the anterior half of the eye to which the
vitreous humor probably remains attached. Look for the
hyaloid membrane. "What are its functions ? To what is it
attached? Gently separate the vitreous humor from the
lens and ciliary processes and let it float in the water. De-
scribe its color, consistency and functions. Have you seen
anything of the ora serrata ? NOAV examine the ciliary
processes and discuss their relations to the choroid and to
the lens. Where are the ciliary muscle fibers? What is the
innervation of this muscle ? What are its points of origin
and of insertion? What are its functions ? What drugs act
on it and how do they act ?

With care dissect away a small sector of the suspensory
ligament of the lens. What is the canal of Petit ? Where
are the spaces of Fontana located and what is their func-
tion? What drugs may influence this function and how?
What is the canal of Sclennn? Remove the entire lens. If it
is sufficiently transparent lay it over some small print and
see if the letters can be seen through the lens. How many
forms of lenses do vou know? To which of these does the

THE EYE AMYL XITRITE 397

crystalline lens belong? How is the eye focused for vary-
ing distances? What part does the lens play in this proc-
ess? Make two diagrams to show these actions. AYhat
drugs may influence these processes and how do the drugs
act?

Examine the iris. Locate the anterior and posterior
chambers. AYith what is each filled ? May drugs influence
these chambers in any way ! If so how ? Can you find any
evidence of the existence of dilator muscle fibers for the
pupil? Where would you look for these? What is the in-
nervation of this set of fillers? What drugs act on the
dilator mechanism and where and how do these drugs act ?
How is the intraocular pressure controlled ? How may
drugs influence this? Can you find the sphincter muscle of
the iris ? How is this muscle innervated ? What part does
it play in accommodation? AVhat drugs may affect this
muscle and how and where do they act ? Compare the iris
of a bird with that of a mammal as regards the action of
atropine, pilocarpine and cocaine. Make a diagram show-
ing the structure and innervation of the eye and indicate
thereon with ledger lines the points where all drugs which
affect the eye and with which you are familiar act. Indi-
cate the nature of these actions with a plus ( + ) sign for
stimulation and a minus (--) sign for depression and paral-
ysis. Describe all nervous paths and elements involved in
the pupillary light reflex. AVhat is an Argyll-Robertson
pupil ?

EXPERIMENT CXVIII.

Amyl Nitrite. (Student: Plethysmographic Record,

General Action.)

1. Arrange your apparatus for taking a volume record
of the arm as shown in Fig. 326. AVhen all adjustments are
made fold a handkerchief over a three (or five) minim amyi
nitrite pearl and prepare to break the pearl by squeezing

398

EXPERIMENTAL PHARMACOLOGY

it with a pair of pliers. (Pearls, or ampoules, are now pre-
pared by several firms already covered by cloth so that
glass particles can not fly off from the ampoule when it is
broken.) Bring the pearl (or ampoule) up close to the sub-
ject's nose and allow the vapors of the drug to be breathed
in at once as the glass container is snapped by the pliers.
Be sure you already have a normal plethysmographic
record started (on a slow drum) before the pearl is broken.

Fig. 326. Plethysmograph for recording volume changes in the hand and forearm.
The rubber