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 .^11! I 
 

 CORNELL UNIVERSITY. 
 
 THE 
 THE GIFT OF 
 
 ROSWELL p. FLOWER 
 
 FOR THE USE OF 
 THE N. Y. STATE VETERINARY COLL^id^ "^ ^/-'o^ 
 1897 
 
CORNELL UNIVERSITV LIBRARY 
 
 3 1924 056 948 841 
 Date Due 
 
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 "'"V^ 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 Library Bureau Cat. No. 1137 
 
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Cornell University 
 Library 
 
 The original of this book is in 
 the Cornell University Library. 
 
 There are no known copyright restrictions in 
 the United States on the use of the text. 
 
 http://www.archive.org/details/cu31924056948841 
 
EXPERIMENTAL PHAEMACOLOGY 
 
 GEEENE 
 
EXPEKIMENTAL PHARMACOLOGY 
 
 A LABOEATOEY GUIDE 
 
 FOE THE STUDY OF 
 
 THE PHYSIOLOGICAL ACTION OF DEUGS 
 
 BY 
 
 CHARLES WILSON gREENE, PH. D. 
 
 PROFESSOR OF PHYSIOLOGY AND PHARMACOLOGY, UNIVERSITY OF MISSOURI. 
 
 THIRD EDITION, REVISED 
 WITH 37 NEW ILLUSTRATIONS 
 
 PHILADELPHIA 
 
 P. BLAKISTON'S SON & CO. 
 
 1012 WALNUT STREET 
 
 1909 
 
Copyright, 1909, by P. Blakiston's Son & Co. 
 
 *- 
 
 Printed by 
 
 The Maple Press 
 
 York, Pa. 
 
PREFACE. 
 
 Instruction in Piiarmacology should be based on a rigid course of 
 required laboratory experiments. The student in the subject must be given 
 every opportunity to observe for himself the changes produced by a drug in 
 the activities of a tissue, of an organ, and of the entire organism. It is only 
 on such intimate personal experience with the facts that one can reach a 
 rational understanding of the principles of Pharmacology. 
 
 The directions presented here have been formulated during the growth 
 of the course as presented in the University of Missouri. Under each drug 
 presented there is given a list of experiments chosen with due consideration 
 to the facility with which they may be performed by students. This list 
 is followed by detailed yet brief directions for the execution of the experi- 
 ments. An occasional type illustration is given to guide the student in his 
 efforts. It is assumed that the individual student will have time for only a 
 selected number of experiments on each drug, and the plan of the Guide is 
 so arranged as to support the instructor in the assignment and execution of 
 a number of diversified experiments by the average laboratory class. 
 
 I am indebted to the Department Teaching Staff, especially to Professor 
 W. Koch, now of the University of Chicago, to Dr. W. H. Schultz, now of 
 the U. S. Public Health and Marine Hospital Service, and to Professor 
 R. B. Gibson for numerous suggestions and much assistance. 
 
 I am under special obligation to Mr. G. T. Kline for the drawings of 
 apparatus, to Professor Gibson and to my students of the past five years 
 for the majority of the new illustrations presented in this edition of the 
 Guide. C. W. G. 
 
 University of Missouki, April, 1909. 
 
CONTENTS. 
 
 THE ACTION OF DRUGS. 
 
 Alcohol 
 
 Ether 
 
 Chloroform . . 
 
 Chloral hydrate . 
 The opium series . . 
 Caffeine . ... 
 
 Strychnine . . 
 
 Cocaine . . . 
 
 Quinine . . . 
 
 Atropine, scopolamine 
 Nicotine 
 
 Curare . . . 
 
 Pilocarpine 
 Physostigmine 
 Aconite . . 
 Veratrine . . 
 
 Digitalis 
 Ergot . . . 
 
 Suprarenal gland . . 
 Nitroglycerine and the 
 Carbolic acid . 
 Potassium salts 
 Calcium salts 
 Barium salts . . . 
 
 nitrites 
 
 PAGE 
 
 I 
 
 6 
 
 II 
 
 14 
 
 IS 
 20 
 
 24 
 
 29 
 
 32 
 
 33 
 37 
 40 
 42 
 
 44 
 48 
 5° 
 
 52 
 SS 
 56 
 
 59 
 61 
 61 
 62 
 63 
 
 OPERATIONS, APPARATUS AND SPECIAL METHODS. 
 
 Physiological solutions . . .64 
 
 Anesthesia for dogs, cats, rabbits, and guinea-pigs . 65 
 
 The preparation of the ventricular muscle .... . 66 
 
 To test the action of drugs on the frog's heart 68 
 
 vii 
 
VUl CONTENTS. 
 
 PAGB 
 
 Irrigating and perfusing flasks 69 
 
 To test the action of drugs on the blood-pressure, respiration, etc., of 
 
 a mammal . . ... .... 70 
 
 Method of testing the action of drugs on the reflexes of a frog 71 
 
 Method of giving and testing the action of a drug on the frog's gas- 
 trocnemius muscle . . 72 
 
 Transfusion buret for mammals . 72 
 
 Apparatus for the study of the isolated mammalian heart .... 73 
 
 List of stock solutions 75 
 
 Report form for experiments on frogs 76 
 
LIST OF ILLUSTRATIONS. 
 
 FIG. PAGE 
 
 1. Alcohol perfused through the frog's heart 2 
 
 2. Ether on the isolated muscle of the terrapin's ventricle ... . 7 
 
 3. Strong ether solutions on the isolated ventricular muscle. 8 
 
 4. Ether on tone waves of auricular and sinus muscle. . 9 
 
 5. Ether on the irritability of the sciatic nerve 10 
 
 6. Chloroform on the rhythm of heart muscle 12 
 
 7. Chloroform perfusion of the frog's heart . 13 
 
 8. Chloroform on the irritability of nerve . 13 
 g. Morphine on the rhythm of terrapin's ventricle . 16 
 
 10. Morphine on the isolated heart of the cat . . . 17 
 
 11. Morphine on the isolated heart of the cat . 17 
 
 12. Caffeine on the ventricular muscle . . 21 
 
 13. Caffeine on the amount of muscular work 22 
 
 14. Strychnine on the ventricular muscle . . . 25 
 
 15. Strychnine on the muscular work . 26 
 
 16. Strychnine on the isolated mammalian heart . . . 27 
 
 17. Cocaine effects on the frog's heart . . 29 
 
 18. Cocaine on the muscular work . . 30 
 
 19. Quinine on the frog's heart 32 
 
 20. Atropine on the heart muscle . . 33 
 
 21. Atropine on the isolated cat's heart . 34 
 
 22. Nicotine on the ventricular muscle . . 38 
 
 23. Nicotine on the isolated cat's heart ... 39 
 
 24. Pilocarpine on the blood-pressure and on the respiration of the dog 42 
 
 25. Physostigmine on the isolated cat's heart . . . 45 
 
 26. Physostigmine followed by atropine on the mammalian blood- 
 
 pressure and respiration . 46 
 
 27. Aconite on the isolated cat's heart. . . . . . 49 
 
 28. Veratrine on the isolated cat's heart . 51 
 
 29. Digitalis on the heart muscle ...... 53 
 
 30. Digitalis on the isolated cat's heart ... 54 
 
 ix 
 
X LIST OF ILLUSTRATIONS. 
 
 FIG. PAGE 
 
 31. Adrenalin hydrochloride on the isolated cat's heart . . 57 
 
 32. Amyl nitrite on the human pulse .... . . 60 
 
 33. Calcium chloride on the terrapin's heart muscle ... 62 
 
 34. The terrapin's heart, how to cut an apex strip . . 67 
 
 35. Apparatus for the study of heart muscular strips . . 67 
 
 36. Apparatus for the study of drugs on the frog's heart . . 68 
 
 37. Apparatus for the study of the action of drugs on the mamma- 
 
 lian heart 74 
 
EXPERIMENTAL 
 PHARMACOLOGY 
 
 THE ACTION OF DRUGS. 
 
 ALCOHOL. 
 
 List of Experiments Showing the Effects of Alcohol. page. 
 
 1. On the frog .... i 
 
 2. On ventricular muscle . . i 
 
 3. On the frog's heart . . 2 
 
 4. On the isolated mammalian heart. .... 3 
 
 5. On the work of the frog's gastronemius muscle. 3 
 
 6. On voluntary work of human muscle. Demonstration . 4 
 
 7. On the circulatory and respiratory systems of the mammal . 4 
 
 8. On the reaction time of the reflex frog . ... 5 
 
 1. Alcohol on the frog. Inject into the dorsal lymph sacs of two 
 frogs doses of 0.3 c.c. (5 minims) and 0.6 c.c, respectively, of 95 percent 
 alcohol.' Strong alcohol is quickly absorbed from the lymph sac. The 
 larger dose is sufficient to produce temporary complete loss of the reflexes, 
 together with the loss of all respiratory movements. A dose of i c.c. 
 is toxic for a 40-gram frog. Since the smaller dose is equivalent to 525 c.c. 
 for a 7c-kilo man, it is evident that the frog is the more tolerant of alcohol.^ 
 
 2. Alcohol on ventricular muscle. Mount a strip of the ventricle 
 of a terrapin in 0.7 percent sodium chloride (see page 66 for the method), 
 and when it is contracting with an even and regular rhythm change to a 
 solution of 2 percent alcohol in" physiological saline. Return the strip to 
 
 'All doses for frogs given in this book are calculated for an animal weighing 40 grams. 
 Each animal used for experiment should be weighed on a "Harvard" platform balance and 
 the dose given calculated in proportion to the weight of the animal used. 
 
 "A report blank form for the tabulation of observations on the effect of drugs on frogs is 
 given on page 76. 
 
2 EXPERIMENTAL PHARMACOLOGY. 
 
 pure saline solution after two to five minutes. Record the contractions on a 
 drum moving i mm. a second. Repeat the experiment', using successive 
 strengths of alcohol of 5 and 10 percent. The alcoholic effect will be dem- 
 onstrated rather better on a ventricular strip that is contracting regularly 
 in the weaker Ringer's solution, page 64, but the alcohol must be dissolved 
 in Ringer's solution of the same composition. 
 
 3. Alcohol on the frog's heart. Destroy the brain and spinal cord 
 of a frog, expose the heart by cutting away the ventral wall from directly 
 over the ventricle, using care not to lose blood. Do not cut the bridge formed 
 
 Fig. I. — Action of 2 percent alcohol on the frog's heart when perfused through 
 the ascending vena cava. The alcohol was dissolved in Ringer's solution. The 
 record was taken from the tip of the ventricle by the suspension method. Time in 
 seconds and minutes. Perfusion began at the first arrow above the second's record and 
 ended at the second arrow. 
 
 by the sternum, but use it as a fixed point to which the heart may be anchored 
 by a ligature around one of the aortic arches. Take a direct record of the 
 movements of the ventricle, using a light straw lever of the fulcrum-power- 
 weight order. Give 1.5 c.c. of 95 percent alcohol in the abdominal 
 cavity. Take a continuous record during the time of absorption. This 
 method demonstrates the effects on the volume, and on the type of systole 
 and diastole. The rate is only slightly changed. 
 
 More satisfactory results are obtained by perfusing the heart through a 
 canula in the ascending vena cava. Perfuse the alcohol from four-ounce 
 supply flasks provided with constant level tubes. Use a pressure of from 
 4 to 6 cm. The perfusion strength to use by this method is 2 to 5 percent 
 alcohol made up in Ringer's solution. Perfuse the heart for from two to 
 
ALCOHOL. 3 
 
 four minutes at a time. Record the contractions of the ventricle. by a thread 
 from its tip to the vertical arm of a balanced lever, page 68. In this experi- 
 ment, as in all frog's heart perfusion, it is better to use the weaker Ringer 
 for the normal solution. The Ringer's solution insures a uniform heart 
 rate and strength for long intervals, while the sodium chloride solution 
 will sustain the whole heart in regular and strong rhythm for only a few 
 minutes. 
 
 4. Alcohol on the isolated mammalian heart. Use a rabbit or a 
 cat for this experiment. Anesthetize quickly with ether (do not use chloro- 
 form) , insert a canula in the carotid, bleed completely, defibrinate the blood 
 and dilute it with nine volumes of Locke's solution. Use this diluted blood 
 as a normal solution for perfusing the heart. Reserve enough of the solution 
 for making the drug mixtures, pour the remainder into the perfusion appara- 
 tus described on page 73, fill the tubes, adjust the apparatus and bring to a 
 constant temperature of 36 to 37° C. (a higher temperature is unfavorable). 
 Quickly remove the heart, taking care only to preserve enough of the aorta 
 for the insertion of the canula without danger of interfering with the semi- 
 lunar valves. Mount the heart without catching air in the canula, attach the 
 recording lever of the Guthrie cardiograph and start the perfusion. The 
 perfusion pressure should be from 80 to 100 cm. of water. 
 
 The heart contracts and a uniform rhythm will be quickly established 
 and may be maintained for several hours. Perfuse the heart with 0.2 
 percent alcohol in the Locke-blood solution for from 30 to 100 seconds 
 at a time, allowing full time for a return to the normal after each drug 
 perfusion. Raise the dose successively to 0.4 percent, i percent, and 2 
 percent of alcohol. The stronger solutions reduce the amplitude and 
 ultimately the rate of the heart; the weaker doses, according to Dixon, in- 
 crease the amplitude. 
 
 5. Alcohol on muscular work. Ligate one leg of a frog near the 
 thigh to exclude its circulation (a quarter-inch rubber tube makes a fine 
 ligature for this purpose). Inject 0.3 c.c. (5 minims) of 95 percent 
 alcohol into the dorsal lymph sac. In exactly twenty minutes pith the 
 frog, pin it out on the frog-board with the ventral side down, and ligate the 
 alcoholized leg. Quickly prepare the tendon of the normal muscle, keeping 
 the muscle covered with skin, attach to the muscle lever, and determine the 
 work it can do by stimulating the muscle directly with a single induction 
 shock once every two seconds until the muscle is completely exhausted. 
 Load the muscle with a 30- to 50- gram weight. Record the contractions on 
 the lower half of a drum with a speed of i mm. a second. 
 
4 EXPERIMENTAL PHARMACOLOGY. 
 
 Prepare the second or alcoholized muscle just twenty minutes after it 
 has been ligated, mount, load, and stimulate in the same manner. Record 
 the second experiment on the upper half of the same smoked papef and 
 parallel with the record of the first. Repeat this experiment using a dose 
 of 1 CO. of 95 percent alcohol, to demonstrate the injurious effects of 
 alcohol on the work of the muscle. (Lee and Salant, Am. Jour. Physiology, 
 Volume VIII, p. 6i, 1902.) 
 
 A more difficult but more accurate experiment is obtained as follows: 
 Destroying the brain only of a frog, pin it to the frog-board belly down, 
 dissect out the right tendon Achilles, and attach to a muscle lever. Isolate 
 the lumbar plexus on the right of the urostyle, using care not to interfere 
 with the circulation of the gastrocnemius. Stimulate the right muscle as 
 above. Now inject alcohol into the abdominal cavity, and after 20 to 30 
 minutes of absorption measure the work of the left gastrocnemius. This 
 method has the advantage of maintaining the circulation intact for both the 
 normal and the alcoholized muscle. 
 
 The effect of alcohol on the speed of the contraction can be determined 
 by one of two methods. Que can measure the simple muscle contraction 
 before and after alcoholization. Perhaps a better method is to use Lee's 
 automatic stimulating device (Am. Jour. Physiol., VIII, p. 61) which auto- 
 matically stimulates a muscle at the moment of complete relaxation. Re- 
 cord the contractions on a slowly moving drum, 2 mm. per second. 
 
 6. Alcohol on voluntary work of hiunan muscle. Demonstration. 
 Measure the voluntary power of the flexors of the middle finger with a load 
 of three kilos or more, using Mosso's ergograph. Take two or three normal 
 records of voluntary contractions at intervals of 20 minutes. Now take a 
 dose of 20 to 40 c.c. of 20 percent alcohol, according to the susceptibility 
 of the individual. Remeasure the muscular power after 60, 90, and 120 
 minutes, respectively. Compute the work done in kilogrammeters. (Lom- 
 bard, Jour. Physiol., Vol. 13, p. 49; Hallsten, Skand. Arch. f. Physiol. Bd. 
 16. S. 139.) 
 
 7. Alcohol on the circulatory and respiratory systems of the 
 mammal. Anesthetize a dog with morphine and chloroform, p. 70. 
 Take the blood-pressure from the carotid artery, and the respiration from a 
 side branch of a tracheal canula. Expose the saphenous vein and insert 
 a canula for intravenous injections, and attach it to a 50 c.c. buret. 
 
 Students who have attained the requisite skill should take an onkomet- 
 ric record with the blood-pressure. To prepare for this record open the 
 abdominal cavity of the dog, remove the outer sheath from the left kidney 
 
ALCOHOL. 5 
 
 and enclose that organ in a renal onkometer. Record the kidney volume 
 changes by means of a Brodie's bellows, or Roy's piston recorder, page 71. 
 
 The anesthetic must be given with perfect regularity, 2 to 6 drops of 
 chloroform every 30 seconds, the exact amount that will maintain constant 
 anesthesia to be quickly ascertained for each animal. 
 
 Take a record on the continuous kymograph and, when all is in good 
 working condition and a normal record has been secured, slowly inject 20 
 percent wanned alcohol from the buret into the vein imtil some decided 
 effect on the blood-pressure is noted, i.e., after a dose of 20 c.c. or more. 
 Extreme caution must be observed lest the heart by rapid perfusion be sub- 
 jected to an overconcentrated solution. The experiment should be re- 
 peated with different doses. 
 
 Since the anesthetics used all depress the irritability of the circulatory 
 apparatus, this experiment ought to be demonstrated on a decerebrate ani- 
 mal. In such an animal the medulla being intact will maintain natural 
 respirations. Any alcoholic stimulation of the medullary centers can easily 
 be observed. The recommended intravenous dose of alcohol will produce 
 slowing of the heart, a phenomenon which disappears on section of the vagi, 
 thus indicating a direct effect on the vagal centers. 
 
 8. Alcohol on the reaction time of the reflex frog. Destroy the 
 brain of a frog, including the medulla, and when it has recovered from the 
 shock test the normal reaction time to electrical stimuli applied to the toe. 
 Measure the time of the reaction with a watch, or record it with a writing- 
 point attached to the foot or leg of the suspended frog. Give a dose of 0.3 
 c.c. (5 minims) of 95 percent alcohol in the dorsal lymph sac. Retest 
 the reaction time at exactly 20 and 40 minutes after the injection. Com- 
 pare the results with experiments i and 5 above. 
 
EXPERIMENTAL PHARMACOLOGY. 
 
 ETHER. 
 
 List of Experiments Illustrating the Effects of Ether. page. 
 
 1. On the frog 6 
 
 2. On the ventricular muscle 6 
 
 3. On the frog's heart 7 
 
 4. On the mammalian heart . 7 
 
 5. On the irritability of voluntary muscle. 7 
 
 6. On the irritability of nerve tissue . . . 9 
 
 7. On the blood-pressure and respiration of a mammal 9 
 
 8. On the germination of seeds 10 
 
 9. On the growth of yeast . . 11 
 
 1. Ether on the frog. Inject 0.2 c.c. (3 1/2 minims) of ether' into 
 the dorsal lymph sac or the abdominal cavity of a frog. Give 0.3 c.c. to a 
 second frog. The dose can be given more accurately from the hypodermic if 
 a 50 percent solution of ether in olive oil is used. The first dose will produce 
 anesthesia in about 10 minutes. The stages most readily observed are : ist, 
 great excitement shown by rapid respirations, active movements, and 
 increased reflex irritability; 2d, slower respirations, very sluggish • response 
 to external stimulation; 3d, loss of voluntary muscular control and sometimes 
 of respiratory motions. Slight power of reflex response is retained, including 
 eye reflexes. The voluntary motions will be regained in from 60 to 90 
 minutes if the animal is kept moist (winter frogs), and complete recovery 
 in two hours. The frog will recover from the larger dose in from 20 to 24 
 hours, or it may even fail of recovery. 
 
 2. Ether on the ventricular muscle. Mount a strip of terrapin's 
 ventricle and establish rhythmic contractions in a bath of 0.7 percent saline. 
 Record on a drum moving i to 2 mm. per second. Immerse the strip in a 
 bath of I percent ether in saline for two to three minutes, then return 
 to the physiological saline bath. The sharp decrease in both amplitude 
 and rate of contractions is recovered quickly in the saline bath. 
 
 Repeat the experiment using 2, 4, and 6 percent ether solutions. 
 
 The weaker solutions occasionally produce slight but temporary increase 
 
 in the rate, the initial excitation stage. Also use strips of auricle and sinus. 
 
 'The dose is figured for a 40-gram frog. Proportionate doses should be given for other 
 weights. In all experiments on frogs that depress their functions, the animal should be retained 
 in a moist bell jar for as much as 24 hours, if necessary, in order to test the animal's power of 
 recovery. 
 
ETHER. 7 
 
 3. Ether on the frog's heart. Pith a frog, expose its heart, insert 
 a canula in the inferior vena cava and perfuse the heart in place by the 
 method described for alcohol, experiment 3. This brings the solution into 
 intimate contact with the entire heart and it responds almost instantly to 
 any change in the composition of the irrigating fluid. Perfuse the heart 
 first with Ringer's solution and follow with i percent ether in Ringer's 
 solution. 
 
 4. Ether on the mammalian heart. Use the Roy-Adami method 
 (given by Cushny, Jour. Exp. Medicine, Volume II, page 233) or the 
 
 Fig. 2. — The action of ether on isolated heart muscle. In this experiment a strip 
 of terrapin's ventricle was mounted in physiological saline until a regular rhythmic 
 beat was established. The saline was then drawn off and the strip left suspended in 
 moist air. At the point indicated ether vapor was driven through the moist chamber 
 until the contractions ceased. The ether vapor was then removed with moist air 
 at the second arrow and the recovery of the rhythm took place as shown. 
 
 method described on page 73 and used in experiment 4 of the alcohol 
 series. Etherize a cat or rabbit, draw the blood, defibrinate it, and dilute 
 it with nine volumes of Locke's solution and use as a standard Locke-Blood 
 perfusion fluid. Remove the heart and adjust it in the apparatus, page 74. 
 Perfuse with the Locke-Blood solution and when the rhythm is established 
 change to i percent ether in Locke-Blood. Use 2 percent ether in a 
 later experiment. 
 
 5. Ether on the irritability of voluntary muscle. Mount a gas- 
 trocnemius of the frog in the moist chamber, arrange to stimulate the 
 muscle directly with a current of medium intensity but which produces a 
 maximal contraction. Adjust a vapor apparatus containing saturated 
 
EXPERIMENTAL PHARMACOLOGY. 
 
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ETHER. 9 
 
 ether water ready for quick connection with the gas tube of the moist 
 chamber. Stimulate the muscle with single induction currents once every 
 30 seconds throughout the entire experiment, whether contractions are 
 secured each time or not. Record on a drum having a rate of 2 mm. per 
 10 seconds. 
 
 Take records, three or four normal contractions, then turn on the ether 
 vapor for five minutes. Quickly remove the vapor with a current of fresh 
 air. The muscle's irritability will decrease to a point at which the stimulus 
 is submaximal or even subminimal, but when the ether vapor is removed 
 the contractions quickly reappear and attain their former amplitude. Use 
 small muscles for this experiment. 
 
 Fig. 4. — The action of ether on isolated strips from the auricle (upper trace) and 
 from the sinus (lower) of the terrapin. The strips were giving tone contraction waves, 
 but no fundamental rhythm when bathed with normal sodium chloride solution. At the 
 mark "on" the sodium chloride was changed to one percent ether in normal saline 
 for seven minutes, then again to the normal. During the ether bath the tone waves 
 disappear, a condition which lasts for three minutes after the ether is removed. Fol- 
 lowing the ether there is a renewal of the tone waves which are even more rapid than 
 in the normal. Time in minutes. 
 
 One may with this preparation also demonstrate that the muscle has a 
 diminished power to do work when etherized, method page 72. 
 
 6. Ether on the irritability of nerve tissue. Prepare a muscle 
 nerve of the frog, isolating the entire sciatic with a piece of cord, and with the 
 skin covering the muscle. Mount the preparation with the nerve in the 
 moist chamber and on the electrodes, but with the muscle hanging through 
 the hole in the floor of the moist chamber and on the outside so that it will 
 not be etherized. Close the hole with a sheet of moist filter-paper. Proceed 
 exactly as in experiment 5 above testing the irritability of the nerve through 
 its effect on the muscle. 
 
 The influence of ether on nervej irritability may also be demonstrated 
 directly from the nerve by the action' current method. For a description of 
 the method, see Am. Jour. Physiol., Volume I, p. 104. 
 
 7. Ether on the blood-pressure and on the respiration of the 
 mammal. Anesthetize a dog with morphine and ether. Introduce an 
 
lO EXPERIMENTAL PHARMACOLOGY. 
 
 arterial canida in the carotid for taking the blood-pressure record, see page 
 70 for details of method. Insert a tracheal canula and take a record of intra- 
 tracheal pressure from a T-tube attached to the canula. Give ether from 
 an ether bottle connected to the end of the tracheal tube. Take a continuous 
 record and ultimately give excess of ether, then allow partial and guarded 
 recovery. Give ether to the point where respirations cease, a point attained 
 with difficulty except when the animal has a large dose of morphine. The 
 blood-pressure is an index of safety, for it has been shown that respiratory 
 impulses are quickly re-established when the blood-pressure remains high. 
 Saturated ether in saline as an intravenous injection in doses of 20 c.c. 
 and more, given along with a uniform administration of ether by the trachea. 
 
 Fig. 5. — The influence of ether vapor upon the irritability of the sciatic nerve 
 in the muscle-nerve preparation of a frog. The muscle-nerve preparation was sus- 
 pended in a moist chamber with the muscle hanging through the opening in the cham- 
 ber. The first two contractions are normal. The next eight are successive contrac- 
 tions at intervals of ten seconds during the passing of ether vapor. At the X the 
 ether vapor was removed by a stream of moist air, the nerve being stimulated at inter- 
 vals of ten seconds until recovery of the irritability as shown by the contractions at the 
 last part of the experiment. A gap of two minutes occurs at X, during which the nerve 
 was not irritable. Time in seconds. 
 
 will often demonstrate the characteristic circulatory and respiratory effects 
 of the drug. 
 
 The rectal temperature should be recorded at intervals to demonstrate 
 the fall of temperature under anesthetics. Note also the state of dilatation 
 of the pupil. 
 
 8. Ether on the germination of seeds. Arrange two eight-ounce 
 wide-mouth bottles with stoppers each fitted with two glass tubes, letting 
 one tube extend to near the bottom of the bottle. Suspend in each, by 
 means of cotton, a dozen seeds — corn, wheat, clover, beans, etc. — and in- 
 troduce just enough water to maintain a saturated vapor. Set both bottles in 
 a window. Twice a day for a week, pass through one saturated ether 
 
CHLOROFORM. II 
 
 vapor, through the other air. The seeds in both will swell from the ab- 
 sorption of the water, but only the seeds in the bottle with pure air intro- 
 duced will grow. Reverse the two. The sprouting grain will have its 
 growth checked and the etherized seeds will begin to grow. 
 
 9. Ether on the yeast. Take two fermentation tubes of active yeast 
 culture, add 2 c.c. pure ether to one. Note the relative rate of gas liberation. 
 
 CHLOROFORM. 
 
 List of Experiments Illustrating the Effect of Chloroform. page. 
 
 1. On the frog. 11 
 
 2. On the heart strip. 11 
 
 3. On the frog's heart. 11 
 
 4. On the mammalian heart. 12 
 
 5. On muscular irritability. . 12 
 
 6. On nerve irritability. 12 
 
 7. On the blood-pressure and respiration of a mammal. 12 
 
 8. On the kidney secretion. 14 
 
 9. On germinating seeds. 14 
 
 1. Chloroform on the frog. Inject 0.06 c.c. of pure chloroform 
 or 0.3 c.c. of 20 percent chloroform in oHve oil into the dorsal lymph 
 sac or into the abdopiinal cavity of a frog. The anesthesia is more pro- 
 found and the reco^'ery less rapid than in the case of ether. Determine the 
 relative intensity of action of chloroform and ether by your own experiments. 
 
 2. Chloroform on the heart strip. Proceed as with ether in ex- 
 periment 2, page 6, using a 0.05 percent solution of chloroform in 0.7 percent 
 saline for one to three minutes. The contractions cease almost at once. 
 Recovery in saline takes place very slowly. In comparison with ether the 
 period of anesthesia is long. The amplitude of the first contractions to 
 reappear is very slight and the recovery rate slow and irregular. The 
 original character of activity is not restored within 20 to 40 minutes. Re- 
 peat using a solution of o.i percent chloroform. 
 
 An instructive picture is given by parallel records of experiments on 
 strips from the same heart showing the effects of 4 percent ether and of 
 o.i percent chloroform for two minutes, both in saline. 
 
 3. Chloroform on the frog's heart. Proceed as in the siinilar ex- 
 periment with ether, page 7, using 0.5 percent chloroform in physiolog- 
 ical saline to irrigate the outer surface of the heart. Or perfuse the heart 
 
12 
 
 EXPERIMENTAL PHARMACOLOGY. 
 
 bo o <N 
 
 ■2 S <„ 
 
 (U <4-( XI 
 
 g g « 
 
 with 0.05 percent chloroform in saline 
 through the vena cava. Care must be 
 used not to prolong the action of the drug. 
 The amplitude is reduced to one-half and 
 the rate markedly slovi^ed or entirely sup- 
 pressed. Both rate and amplitude are 
 recovered, but not so quickly as with ether. 
 
 4. Chloroform on the mammalian 
 heart. Determine the action of chloroform 
 on the isolated cat's heart, using the method 
 described for the alcohol experiment 4, 
 page 3. Perfuse the heart with chloro- 
 form 0.02 to 0.05 percent in the Locke- 
 blood. The chloroform perfusion must be 
 for short periods and be guarded closely. 
 
 5. Chloroform on the muscular 
 irritability. See ether experiment 5, page 
 3. Use o.i percent chloroform water 
 in the vapor apparatus. Care must be 
 taken to remove the saturated chloroform 
 vapor from the vapor apparatus just before 
 using, otherwise the muscle, or the nerve 
 in the next experiment, will be over anes- 
 thetized and will not recover its irritability. 
 There is no danger with ether from this 
 cause. 
 
 6. Chloroform on the irritability of 
 the nerve. Repeat ether experiment 6. 
 Use o.i percent chloroform water in the 
 vapor apparatus. 
 
 7. Chloroform on the blood- 
 pressure and on the respiration of a 
 mammal. Proceed as with ether experi- 
 ment 7, page 4, using chloroform to anes- 
 thetize the dog or cat (rabbits are too 
 sensitive to chloroform for use in this ex- 
 periment except in practiced hands). Re- 
 member that chloroform is said to be 
 about forty times as strong as ether in its 
 
CHLOROFORM. 
 
 13 
 
 general effects on the animal body. If the vagi are intact and the animal 
 is anesthetized without tracheotomy there will be marked slowing of the 
 heart rate together with a sharp fall of blood-pressure. This effect is 
 
 Fig. 7. — Chloroform perfusion of the frog's heart. Ringer's solution used for the 
 normal, o.i percent chloroform between "on" and "off." Perfusion pressure 
 4 cm. Record from the suspended apex. Time in seconds. 
 
 eliminated by section of the vagi. With extreme care chloroform anesthesia 
 may be pushed to the point where respirations cease, and the animal be 
 recovered without artificial respiration. Often, however, in 5 to 10 seconds 
 
 Fig. 8. — The effect of chloroform on the irritability of the nerve in the muscle- 
 nerve preparation. The first two contractions represent the normal amplitude upon 
 stimulating the nerve of a preparation mounted in a moist chamber. The muscle was 
 allowed to hang through the opening in the floor of the moist chamber, so as to protect 
 it from chloroform vapor. At the point indicated by the word "on" chloroform vapor 
 was driven through the moist chamber. The nerve was stimulated at regular inter- 
 vals until no further contractions occurred. The chloroform was next removed 
 with moist air and the stimulations continued. After a short interval contractions 
 gradually resumed until they reached their normal maximum. 
 
 after respirations cease, the blood-pressure will suddenly sink to a low 
 level, and the heart will become weak and slow (see experiment 8 below). 
 
14 EXPERIMENTAL PHARMACOLOGY. 
 
 a state from which recovery can be secured only by rapid and vigorous 
 artificial respiration. 
 
 Give chloroform intravenously in doses of lo to 20 c.c. of 0.5 percent 
 solution in saline, allowing plenty of time for recovery in each test. Com- 
 pare with alcohol and ether. 
 
 8. Chloroform on the secretion of the kidney. Anesthetize a dog 
 with morphine, i c.c. of i percent, and chloroform, avoiding deep anesthesia 
 during the preliminary preparations. Insert a ureter canula and connect 
 it with a horizontal glass tube mounted on a graduated scale, or see methods, 
 page 70. Take a continuous record of the arterial pressure. 
 
 Now determine the normal rate of secretion of urine per 10 minutes 
 for at least 40 minutes, keeping the dog under light but constant anesthesia. 
 Inject intravenously 10 c.c. of 0.5 percent chloroform solution in saline. 
 Double the dose if necessary until profound anesthesia with low blood- 
 pressure and weak heart is obtained. Or produce deep anesthesia by means 
 of the respiratory inhalations. Recover and maintain light anesthesia for 
 an hour or more. The circulation is quickly re-established in good condi- 
 tion, hilt the secretion of urine which is suppressed during the stage of 
 deep anesthesia is more slowly brought up to the normal with the re-establish- 
 ment of good circulation. 
 
 9. Chloroform on germinating seeds. Repeat the experiment 
 described for ether, page 11, passing air from saturated chloroform water into 
 one bottle of seed, and pure air into the other. After the seeds in air have 
 sprouted, reverse the bottles. Both seeds and young growing plants are 
 anesthetized by chloroform. The seeds may not grow later, as the drug kills 
 plant protoplasm when given beyond a rather narrow limit of both time 
 and concentration. 
 
 CHLORAL HYDRATE. 
 
 Experiments Showing the Effects of Chloral Hydrate. page. 
 
 1. On the frog. . 14 
 
 2. On the rabbit or cat. . . 15 
 
 3. On the heart of the frog. . . 15 
 
 4. On the heart muscle. . 15 
 
 I. Chloral hydrate on the frog. Give a hypodermic injection of 
 0.5 c.c. of 2 percent chloral hydrate dissolved in 0.7 percent saline. 
 Keep the animal in a moist battery jar until complete recovery. Give 
 particular attention to the effects on the circulatory and the nervous systems. 
 
THE OPIUM SERIES. 1 5 
 
 2. Chloral on the rabbit or cat. Give a hypodermic injection of 
 2 c.c. of 2 percent chloral hydrate per kilo of body weight in saline. 
 Repeat in sixty minutes if necessary to produce the chloral narcosis. Make 
 close comparison with the effect of morphine and strychnine. 
 
 3. Chloral hydrate on the frog's heart. Pith a frog and take trac- 
 ings of the ventricle when irrigated over the surface with i percent chloral 
 hydrate. Or perfuse the heart with 0.2 percent chloral hydrate in 
 Ringer's solution and take tracings of the ventricle by the method described 
 on page 69. Note that the recovery period is unusually long. 
 
 4. Chloral hydrate on heart muscle. Prepare a ventricular strip 
 of the terrapin and establish contraction in a bath of 0.7 percent sodium 
 chloride as usual. Change to a bath of o.i percent chloral hydrate 
 in sodium chloride. Stronger solutions may suppress the rhythm entirely. 
 
 THE OPIUM SERIES. 
 
 Experiments Illustrating the Effects of Morphine, Codeine and The- 
 baine. page. 
 
 1. On the frog. 15 
 
 2. On the mammal. 15 
 
 3. On ventricular muscle. 16 
 
 4. On the frog's heart. 18 
 
 5. On the mammalian heart. 18 
 
 6. On the reflex reaction time. . 18 
 
 7. On the volume of air breathed. ... 18 
 
 8. The morphine group on the circulation and respiration in 
 
 the mammal. 18 
 
 1. Morphine on the frog. Give a dose of i c.c. of 2 percent mor- 
 phine acetate in physiological saline in the dorsal lymph sac. Keep the 
 animal under observation for two or more hours to secure the later efiects 
 in the frog. An instructive comparison is had by giving a dose of 0.5 c.c. 
 (8 minims) of o.i percent strychnine nitrate to a second frog at the same 
 time. Keep the frog under observation until complete recovery. 
 
 Give a second frog an injection of i c.c. of i percent codeine in phy- 
 siological saline. Compare with morphine. 
 
 The dose of thebaine for the frog is i c.c. of i percent. 
 
 2. Morphine on the mammal. Give a hypodermic injection of 1.5 
 c.c. of 2 percent morphine under the skin of the shoulder, see anes- 
 
i6 
 
 EXPERIMENTAL PHARMACOLOGY. 
 
 thesia, p. 65. Keep the animal 
 under observation for at least 
 two hours and note at intervals 
 the temperature, irritability, 
 respiratory, ocular, and other 
 changes under the influences of 
 the drug. If vomiting is pro- 
 duced a concentrated watery ex- 
 tract of the vomit will show the 
 presence of morphine, thus 
 demonstrating that excretion of 
 morphine takes place into the 
 stomach. 
 
 3. Morphine on the ven- 
 tricular muscle. Prepare a 
 strip of the ventricle of a terrapin 
 and get it into regular contrac- 
 tions by a bath of 0.7 percent 
 sodium chloride. Change the 
 strip to a bath' of i percent 
 morphine in sodium chloride 
 for five minutes, or until a 
 marked change in the rate and 
 amplitude of the contractions 
 occurs, after which the strip 
 should be returned to saline. 
 Record the contraction on a 
 smoked drum moving with a 
 speed of I to 2 mm. a second. 
 This experiment shows that the 
 contractions of cardiac muscle 
 are weakened and slowed under 
 morphine. Repeat, varying the 
 conditions according to the re- 
 sults of the previous experiment. 
 A stronger solution of morphine 
 will inhibit all heart muscle 
 activity for many minutes or 
 even hours. The proper 
 strength of codeine for this 
 
THE OPIUM SERIES. 
 
 17 
 
lo EXPERIMENTAL PHARMACOLOGY. 
 
 experiment is, 0.5 percent, in physiological saline, of thebaine about i 
 percent soliition. V ' ^ i'" 
 
 4. Morphine on the f fog's heart. PitH at fi-og, expose tKe heart 
 and take a record of' its contrafetions, either by the perfusion or by, the sus- 
 pension method. Test the irritability of the vagus' t^unk. If the circulation 
 is still effective give, a lymph saC injection of 0,5 c.c. of 10 percent mor- 
 phine acetate of apply drops ol this solution directjy to the heart from the 
 dropping bottle. Retest the effectiveness of thei Vagus stiniulation. - If the 
 heart is perfused, the effective solution to use is 0.5 percent of morphine 
 acetate in Ringer's solution. ; ' 
 
 5. Morphine on the mammalian heart.— Etherize a cat, collect its 
 blood and isolate its heart as described in alcohol experiment 4. Fill the 
 tubes of the mammalian heart perfusion apparatus, bring the apparatus to a 
 temperature of 36° C, adjust the heart in it and begin the normal perfusion. 
 When the heart is contracting with a regular and relatively even rhythm 
 perfuse it for two minutes with 0.5 percent morphine in Locke-blood solu- 
 tion. Repeat the experiment using i percent solution. If the perfusion 
 is too prolonged the heart depression will be removed only with the greatest 
 difficulty. 
 
 6. Morphine on the reflex reaction time. Test the reaction time 
 in a reflex frog in the usual way, see methods page 71, first on the normal 
 animal, then 20 and 40 minutes after a dose of i c.c. of 4 percent morphine 
 acetate. 
 
 7. Morphine on the voltmie of air breathed. Anesthetize a rabbit 
 (or cat) with two grams urethane and ether, administering the latter at 
 perfectly regular intervals and with a constant number of drops. Keep a 
 continuous record of the respiration rate per minute either by counting or by 
 recording on a smoked drum. Measure the respiration volume as follows: 
 Insert a tracheal canula and connect it with an apparatus for measuring the 
 volume of expired air. Ether can be given through the open' tube of the 
 apparatus except when actually 'measuring the air volume. Fill the grad- 
 uated cylinder with water. Then measure the voliime of eight or ten expi- 
 rations, according to the volume of the apparatus used, and repeat several 
 times to secure reliable averages, of the expiratory volume of the etheriz;ed 
 animal. Compute the expiratory volume per minute. Now give i c.c. of 
 2 percent morphine hypodermic. Remeasure the respiratory rate and 
 expiration volume at intervals of 10 minutes. 
 
 8. The morphine group on the circulation and on respiration in 
 the mammal. Anesthetize a dog with chloroform (no morphine), take the 
 
THE OPIUM SERIES. I9 
 
 blood-pressure from the carotid, insert a tracheal canula and take the 
 respiration by the intratracheal method. Insert a canula into the saphen- 
 ous vein and connect with a buret for intravenous injections. (One may 
 readily insert a canula into the ureter and follow the secretion of urine 
 under the morphine. Consult the instructor.) 
 
 Give an intravenous injection of 2 c.c. of 2 percent morphine in saline. 
 The injected solution should be about the temperature of the body. Repeat 
 after ten minutes, using 4 c.c. When equilibrium is reestablished give 
 2 c.c. of I percent codeine. Give 2 c.c. of i percent thebaine. Give 
 thebaine first if there is an opportunity to make the test on a second animal. 
 Now cut the vagus nerves and repeat the dose of 2 c.c. of 2 percent 
 morphine. 
 
 The anesthetic must be gradually diminished according to the amount 
 of morphine, etc., that has been injected. Use artificial respiration if 
 necessary. 
 
20 EXPERIMENTAL PHARMACOLOGY. 
 
 CAFFEINE. 
 
 Experiments Illustrating the Effects of Caffeine. page. 
 
 1. On the frog . . .... 20 
 
 2. On the ventricular muscle . . 20 
 
 3. On the frog's heart . . .20 
 
 4. On muscular irritabiUty and on muscular work. . 21 
 
 5. On voluntary work of human muscle . . .21 
 
 6. On the reaction time in man . 22 
 
 7. On the reflex reaction time in the frog. . . 22 
 
 8. On the mammalian heart . . . . . . 23 
 
 9. On the circulation and respiration in the mammal 23 
 10. As a diuretic . . 24 
 
 1. Caffeine on the frog. The dose is i,c.c. of 0.5 percent caffeine 
 
 in the dorsal lymph sac. There is usually a great increase in the irritability 
 together with muscular cramps in the later stages, and finally paralysis. 
 There may be considerable opisthotonus from the direct muscular effects at 
 the area of injection. Note the recovery stages when the frog is kept in a 
 moist battery jar. 
 
 2. Caffeine on the ventricular muscle. Record the contractions of 
 a strip of terrapin's ventricle beating in physiological saline on a slow-speed 
 drum. Change the strip from saline to o.i percent caffeine in saline for 
 five minutes or less, then back to saline until the contractions become uni- 
 form and typical of the saline curve. Repeat, varying the tim'ig of the 
 immersion in the drug. Increase the strength of the solution to 0.5 per- 
 cent. Ref. — Lingle; Am. Jour. Physiol., VIII, 75. 
 
 3. Caffeine on the frog's heart. Expose the heart of a pithed frog 
 and adjust a balanced lever on the ventricle. Irrigate the surface of the 
 heart with physiological saline from a dropping bottle for a few minutes, then 
 change the irrigating fluid to i percent caffeine in saline for five minutes, 
 after which return to saline irrigation. Repeat once or twice, then apply 
 caffeine continuously until the maximum effect is obtained. Compare 
 especially the auricle with the ventricle in the later stages of the caffeine 
 effect. 
 
 When the heart is perfused through one of the veins then the solution 
 of caffeine should not be stronger than o.ixto 0.2 percent, and the record 
 
CAFFEINE. 
 
 21 
 
 should be taken by the apex suspension method. This method yields the 
 more accurate results. 
 
 4. Caffeine on muscular irritability and muscular work. Lay 
 a tight ligature around the thigh of a frog to close off the circulation in one 
 leg. Give a dorsal lymph sac or abdominal injection of i c.c. of 0.5 percent 
 caffeine. Allow twenty minutes for absorption, then pith the frog and 
 ligate off the caffeinized gastrocnemius. Determine the irritability by 
 the minimal stimulus method and, second, determine the amount of 
 work the muscle will do when stimulated directly once in two seconds 
 
 Fig. 12. — Action of caffeine on the ventricular muscle of the terrapin. Between 
 the marks X-X the strip was immersed in 0.5 percent caffeine in saline. Before and 
 after the caffeine the strip contracted in normal saline. 
 
 until completely fatigued. Use a constant load of 50 grams in this experi- 
 ment. Prepare first the normal gastrocnemius as quickly as possible and test 
 its irritability and the amount of work it will do with uniform load and 
 method of stimulation. Repeat the irritability test and the determination 
 of work using the caffeinized muscle. If the records are taken on the 
 same recording paper, one above the other as in experiment 5, page 3, 
 the comparison is very sharp. 
 
 5. Caffeine on the voluntary work of human muscle. Measure 
 the amount of work of the flexors of the middle finger by means of a Mosso's 
 ergograph while lifting a 3 to 4 kilo weight, one that exhausts the muscle in 
 about 50 contractions. Repeat in thirty minutes. Consider these as 
 normals. Take two cups of strong coffee or 0.3 gram of caffeine in 
 sweetened warm water. Remeasure the work of the flexors as directed 
 
22 
 
 EXPERIMENTAL PHARMACOLOGY. 
 
 above 60 and 90 minutes after taking the caffeine. The amount of the 
 muscular work is usually markedly increased by caffeine. See the next 
 experiment. 
 
 6. Caffeine on the reaction time in man. Arrange a tuning fork 
 vibrating one hundred times per second and a set of signal keys for measur- 
 ing the reaction time to touch. (For details see directions in StirHng's 
 Practical Physiology, page 325.) Determine the normal reaction, then the 
 reaction time at 30, 60, 90 and 120 minutes after a dose of 0.3 gram 
 
 Fig. 13. 
 
 Fig. 13. — Caffeine effect on the amount of work of the gastrocnemius of the frog. 
 The upper tracing is the normal, the lower the opposite muscle after the absorption of 
 
 caffeine in water. This experiment may be performed together with the 
 preceding. 
 
 7. Caffeine on the reflex time in a frog. Prepare a reflex frog 
 by destroying the brain and the medulla. After the shock has passed away 
 determine the reflex reaction time to electrical stimuli applied to the toe of 
 the suspended frog. This time is easily recorded by a paper writing point 
 attached to some part of the foot itself. Give a dose of i c.c. of 0.5 percent 
 caffeine in the dorsal lymph sac. After 30 minutes redetermine the reflex 
 time. Draw conclusions from averages here, as the error of procedure is 
 high. 
 
CAFFEINE. 
 
 23 
 
 8. Caffeine on the mammalian heart. Etherize a cat, bleed it, 
 and dilute the blood with Locke's solution as in the alcohol experiment 4. 
 Prepare the apparatus and raise its temperature to 36° C. Isolate the heart 
 and quickly insert it in the cardiograph and start the circulation of the 
 Locke-blood solution. When the rhythm is regular, perfuse with o . o 2 to 0.2 
 percent caffeine in Locke-blood solution. It is better to begin with a 
 weaker perfusion solution of caffeine and increase the strength through two 
 or three grades, say from o.i to 0.5 percent. 
 
 Fig. 13 (Continued). 
 
 The stimulus was repeated at regular intervals once in two seconds until exhaustion. 
 0.5 c.c. I percent caffeine. 
 
 9. Caffeine on the circulation and respiration of the mammal. 
 
 Give a dog a hypodermic of i c.c. of 2 percent morphine and anesthetize 
 with chloroform. Tracheotomize. Take the arterial blood-pressure from 
 the carotid and the respiratory pressure from the trachea. Insert a canula 
 in the saphenous vein for intravenous injections. Take records on the 
 continuous paper kymograph. After securing a normal record of both the 
 blood-pressure and the respiration give an intra veous injection of 5 to 10 c.c. 
 of 0.5 percent caffeine in physiological saline. Give slowly from a warmed 
 buret. This experiment should begin with the small doses and the doses be 
 gradually increased. See the next experiment on diuretic action. 
 
24 EXPERIMENTAL PHARMACOLOGY. 
 
 10. Caffeine as a diuretic. Prepare a dog as in the preceding experi- 
 ment. Take the blood-pressure and the respiratory rate. Insert a caiiula 
 for venous injections. Open the abdomen in the median line, seek out one 
 ureter near its connection with the bladder, ligate and insert a urethral 
 canula, taking care to make an unobstructed connection. After the flow 
 of secretion has been established, a 2 to 3 mm. rubber tube is connected with 
 the canula and the abdominal opening sewed up. Connect the rubber tube 
 with a I c.c. pipet graduated in o.i c.c. Mount the buret horizontally. 
 Read the rate of secretion by injecting a small bubble of air each five min- 
 utes into the rubber tube at its connection with the buret. 
 
 Determine the rate of secretion under constant anesthesia both before 
 and after 5 to 10 c.c. of 0.5 percent caffeine. Take readings every five 
 minutes for a period of about two hours. 
 
 STRYCHNINE. 
 
 List of Experiments Showing the Effects of Strychnine. page. 
 
 1. On the frog ... . .24 
 
 2. On a mammal, demonstration .... . . 24 
 
 3. On the ventricular strip ... -25 
 
 4. On the frog's heart and cardiac nerves 25 
 
 5. On the irritability and work of voluntary muscle .... 26 
 
 6. On reflex irritability and reaction time. . . . . 26 
 
 7. Local action on the spinal cord . 26 
 
 8. Spasms depend upon cutaneous stimulation 27 
 
 9. Absorbed slowly from the stomach or bladder and readily 
 
 from the intestine or peritoneum . . 27 
 
 10. Stored in the spinal cord 27 
 
 11. On the mammalian heart 28 
 
 12. On the blood-pressure and respiration rate of mammals. 28 
 
 1. Strychnine on the frog. Give a frog a toxic dose of strychnine 
 nitrate, 0.3 c.c. (5 minims) of o.i percent. Give in the dorsal lymph sac. 
 Note the time of the appearance and the successive stages of increased 
 irritability, convulsions, and paralysis. Take fresh frogs and determine the 
 limits of the therapeutic or non-toxic dose, i.e., determine the dose per gram 
 of body weight that will just fail to produce convulsions. 
 
 2. Strychnine on the mammal. Demonstration. Give a rabbit a 
 hypodermic injection of 0.4 c.c. of 0.1 percent strychnine nitrate per 
 
STRYCHNINE. 25 
 
 kilo of body weight. Consult Cushny's Pharmacology for symptoms. 
 Meltzer gives the toxic dose for rabbits as 0.5 mgr. per kilo. Reference, 
 Am. Jour. Physiol., Volume IX, page i. 
 
 3 . Strychnine on the ventricular strip. Suspend a strip "of terrapin's 
 ventricle in physiological saline and, when it is contracting regularly, subject 
 it to a bath of o.i percent strychnine nitrate in saline for five minutes. 
 Return the strip to physiological saline until the contractions are unques- 
 tionably of the saline type. The rhythm and amplitude are both reduced. 
 
 Fig. 14. — Action of strychnine solution on the ventricular muscle of the terrapin 
 In trace a the strip was contracting in physiological saline. At the vertical arrow it 
 was transferred to 0.5 percent strychnine. The contractions are gradually slowed and 
 weakened. Tracings b to g are successive records around a six-inch drum during the 
 recovery which is very prolonged in this experiment. 
 
 4. Strychnine on the heart and cardiac nerves. Pith a frog, expose 
 the heart, take a direct tracing of the movements of the ventricle. Test 
 the vagus activity by stimulating the vago-sympathetic trunk with a current 
 that produces complete inhibition. Next irrigate the surface of the heart 
 from a dropping botde with o.i percent strychnine nitrate in physiological 
 saline. While continuing the irrigation stimulate the vagus trunk at inter- 
 vals of 5 to 10 minutes. Look for a progressive effect on the beat, the rate, 
 and on the cardiac nervous mechanism as demonstrated by th€ results of the 
 stimulation. 
 
26 
 
 EXPERIMENTAL PHARMACOLOGY. 
 
 5. Strychnine on the irritability and work of voluntary muscle. 
 
 Ligate the thigh of one leg of a frog to occlude its circulation, give a dose 
 of 0.2 c.c. of o.i percent strychnine nitrate. In twenty minutes ligate 
 off the other leg, pith the frog (pith immediately if tetanic contractions 
 appear earlier), and determine the irritability of the normal and of the 
 drugged gastrocnemii by the minimal stimulus method. 
 
 Follow the above test by measurement of the work the muscles will 
 do, testing first the normal, and second, the strychnine muscle. Use the 
 method described for experiment 5 under alcohol. The irritability and 
 the work of voluntary muscle are both greatly increased in the therapeutic 
 stage, in sharp contrast to the effect of strychnine on heart muscle. 
 
 St^.l(^r »n, 
 
 m 
 
 iiimaauLiuuuiLi 
 
 I O ,3 C - 0,X.J- H Q 
 
 
 ■ Son -t-Cof/r/r! -J/Zi/oJi 
 
 Fig. 15 — Showing the action of strychnine on the muscular work and on amplitude 
 of the single contractions in the frog's gastrocnemius. The lower series is of the normal 
 muscle, the upper of the strychninized muscle. The dose was 0.25 c.c. of o.i percent 
 strychnine hydrochloride injected into the dorsal lymph sac, after ligation of one leg at 
 the thigh. Absorption was allowed until the first spasms when the frog was pithed. 
 Weight of frog 40 grams. Load 200 grams. One stimulus in three seconds. 
 
 6. Strychnine on reflex irritability and reaction time. Prepare a 
 reflex frog, i. e., destroy only the brain including the medulla. After the 
 shock has passed away, one hour or more, determine the reflex reaction time 
 to electrical stimulation of the toe by the method given on page 71. Now 
 give 0.5 c.c. (8 minims) of 0.02 percent strychnine nitrate. After each 
 ten minutes take the reaction time to electrical stimulation until spasms 
 appear, which ought to be under 60 minutes. 
 
 7. Local action of strychnine on the spinal cord. Cut the cord of a 
 frog at the base of the medulla and destroy the brain. Free the cut end of 
 the cord from the surrounding tissue, and carefully paint it with i percent 
 strychnine nitrate solution. Muscular spasms will be produced or will 
 follow stimulation of the toes of the fore leg. Or stimulate the toe of the 
 
STRYCHNINE. 
 
 27 
 
 hind leg — reflexes of an orderly nature occur, where no general tetanic con- 
 vulsions have been induced by the dose. Pith the cord, all spasms cease. 
 
 8. Strychnine spasms depend also upon cutaneous stimulation. 
 Strychninize a frog and when the spasms are strong and continuous paint 
 the skin with a 2 percent cocaine solution. The cocaine paralyzes the 
 cutaneous sensory apparatus whereupon the convulsions cease. Dip the 
 frog in water to remove the excess of cocaine, its local effect will disappear 
 in about 10 minutes and the strychnine convulsions will reappear. 
 
 9. Strychnine is absorbed very slowly from the stomach or blad- 
 der, but very readily from the intestine and body cavity. Anesthetize 
 a half-grown fasting cat. Ligate both the cardiac and the pyloric orifices 
 
 mm\wmi^\ 
 
 m\WMmBW^i^k'^M^mMm^^M^^ 
 
 mmmm 
 
 ton ■OlJ.Sir-ycknins in Locke-Blocl 
 
 I [ I I 1 I I 1 I 
 
 CZC^. -C.i.,4,M. 
 
 Fig. 16. — Strichnine on the isolated mammalian heart. The heart was perfused 
 with Locke's solution containing 10 percent of the animal's own blood. Between the 
 points marked on and of, a total of 50 seconds, the heart was profused with o.oi percent 
 strychnine hydrochloride. The stock solution of the drug had been carefully neutralized 
 to eliminate any trace of acid effects. Temperature 34° C. Time in seconds. 
 
 of the stomach. Inject 10 c.c. of o.i percent (10 mgrs.) of strychnine 
 nitrate into the stomach. If no spasms occur in 30 minutes then cut the 
 pyloric ligature apd run the stomach content into the intestine. Spasms 
 may be looked for in two minutes or less. If enough strychnine is absorbed 
 from the stomach to produce muscular spasms repeat the second half of the 
 experiment on a second animal, injecting the drug directly into a portion of the 
 intestine. 
 
 Compare absorption from the urinary bladder and from the abdominal 
 cavity in the same manner. 
 
 10. Strychnine is stored in the spinal cord (Lovett, Jour. Physiol., 
 Volume I, p. 99). Inject 10 mgs. strychnine nitrate into the dorsal 
 lymph sac of a large bull frog. Allow 30 minutes for absorption. Then 
 remove the skin and wash away all traces of strychnine that may re- 
 
28 EXPERIMENTAL PHARMACOLOGY. 
 
 main unabsorbed. Take the cord, also an equal amount of other tissue, 
 macerate each in 0.7 percent saline. Inject equal portions of the extracts in 
 the dorsal lymph sacs of two frogs. Allow hours, if necessary, for the symp- 
 toms to develop. This method will detect traces of strychnine too small for 
 chemical identification. 
 
 1 1 . Strychnine on the mammalian heart. Arrange the apparatus 
 for the isolated mammalian heart, bring it to a temperature of 34° to 36° C. 
 Anesthetize a cat or rabbit with ether, bleed and defibrinate the blood and 
 dilute it to ten volumes with Locke's solution. Quickly cut out the heart, 
 insert the canula into the aorta and ligature it, attach the cardiograph, and 
 start the perfusion of Locke-blood solution. Perfuse with 0.005 percent 
 strychnine hydrochloride for 30 secods. The dose may be increased to 
 o.oi or even 0.02 percent but recovery from the latter is very slow and 
 gradual. 
 
 12. Strychnine on the blood-pressure and on the respiration rate 
 of mammals. Anesthetize a lo-kilo dog. Take a continuous record of the 
 blood-pressure from the carotid and of the respiration rate from the trachea. 
 Give an injection of i c.c. of o.i percent solution of strychnine nitrate 
 from a hypodermic into the saphenous vein. One should give close atten- 
 tion to the symptoms of this mild dose which will produce little more than 
 the therapeutic effects. Repeat this injection until the cumulative dose pro- 
 duces convulsions of a mild character. Note that the convulsions may be 
 suppressed here by giving more chloroform. Give especial attention to the 
 blood-pressure conditions during the tetanic spasm, so as to eliminate the 
 strictly passive mechanical factors. 
 
COCAINE. 
 
 29 
 
 COCAINE. 
 
 List of Experiments Showing the Action of Cocaine. 
 
 1. On the frog. ... 
 
 2. On local sensory surfaces. 
 On the heart muscle. 
 On the frog's heart. . 
 On muscle work. . . 
 
 3- 
 4- 
 
 5- 
 
 6. On the circulatory and respiratory systems of the mammal 
 
 PAGE. 
 
 29 
 29 
 
 30 
 30 
 30 
 31 
 
 1. Cocaine on the frog. Give a frog a dorsal lymph sac injection 
 of 0.4 CO. of 0.5 percent solution of cocaine hydrochlorate in physio- 
 logical saline. Observe the symptoms in the usual way. Also examine 
 the vifhite corpuscles of the blood for motility ais compared with the unpoisoned 
 frog. 
 
 2. Cocaine on local sensory surfaces. Paint one-half the surface 
 of your own tongue with a brush wet in 2 percent solution of cocaine 
 
 Fig. 17. — Cocaine effects on the frog's heart when perfused in o.ooi percent 
 Ringer's solution. Time in seconds. 
 
 hydrochloride. Use care not to swallow any of the solution. In 8 to 10 
 minutes compare the sensitiveness of the two halves of the tongue to electri- 
 cal currents by the minimal stimulus method. Test for taste sensations of 
 sweet, of salt. Note also the personal sensations of any character result- 
 ing from the experiment. 
 
 Give one drop of i percent cocaine in the right eye; repeat in 
 three minutes. There is a loss of sensitiveness and the eyeball may be 
 
30 EXPERIMENTAL PHARMACOLOGY. 
 
 touched without pain. Compare the pupils as to size, as to reaction to 
 light. Determine the acuteness of vision of each eye separately at the read- 
 ing distance. Cocaine is an analgesic, but not a perfect mydriatic. 
 
 3. Cocaine on the heart muscle. Prepare a strip of terrapin's 
 ventricle and vs^hen it is beating in physiological saline in good rhythm 
 submit it for from three to five minutes to a bath of o.oi percent cocaine in 
 saline. Record the contractions on a slow drum. 
 
 Fig. 18. 
 Fig. 18. — Effect of cocaine on the muscular work of the frog's gastrocnemius. 
 
 4. Cocaine on the frog's heart and its nervous mechanism. Pith 
 a frog, expose the heart. Take a continuous record of its contractions by 
 the usual method. Irrigate its surface with physiological saline. Test the 
 irritability of the vagus trunk using a medium strength stimulus. Now 
 irrigate the heart for one minute with 0.2 percent cocaine in saline followed 
 by saline. When the cocaine contractions have somewhat recovered, retest 
 the inhibitory power of the vagus. Repeat the test,using two or three 
 drops of I percent solution, and do not wash it off afterward. 
 
 Perfuse the heart with 0.002 percent solution of cocaine in Ringer's 
 weaker solution. This method gives more constant results than does the 
 irrigation and it is to be preferred. 
 
 5. Cocaine on muscle work. Ligate one leg of a frog at the thigh, or 
 use the method described under alcohol. Give a dose of 0.4 c.c. (7 minims) 
 of 0.5 percent cocaine in the dorsal lymph sac. Allow 20 minutes for 
 absorption then ligate the cocainized leg. Load with a 50-grain weight. 
 
COCAINE. 31 
 
 Take records of the contractions of the normal muscle on a drum with a 
 speed of i mm. per second. Stimulate with single break induction shocks 
 once in two seconds until exhausted. Prepare the cocainized gastrocnemius, 
 mount and stimulate with the same rate and load. If the two records are 
 parallel on the same paper, see figure 18, it will demonstrate the comparative 
 difference in work done. Calculate the amount of work per gram of muscle 
 in each of the two preparations. 
 
 ^ 
 
 Fig. 18 (Continued). 
 The endurance of the cocainized muscle is greatly increased. 
 
 6. Cocaine on the circulatory and respiratory systems of the 
 mammal. Give morphine and chloroform to a dog. Insert a tracheal 
 canula. Take the blood-pressure and respiratory records on the continuous 
 paper kymograph. Insert a canula and connect a buret with the saphenous 
 vein. Inject 2 c.c. of i percent cocaine very slowly while watching 
 the blood-pressure as an indicator. 
 
32 
 
 EXPERIMENTAL PHARMACOLOGY. 
 
 QUININE. 
 
 Experiments on the Effect of Quinine. 
 
 1. On the frog. . . . . 
 
 2. On the frog's heart. 
 
 3. On the striated muscle . . . 
 
 PAGE. 
 
 32 
 32 
 32 
 
 1. Quinine on the frog. Inject i c.c. of o.i percent solution of 
 hydrochlorate of quinine into the dorsal lymph sac. In addition to the 
 usual observations, examine the blood of this frog as regards the motility 
 of the white corpuscles. Compare with the blood of a normal frog. 
 
 2. Quinine on the frog's heart. Pith a frog, expose the heart, and 
 take a record of its contractions with physiological saline while perfusing 
 it from a perfusion bottle. Change the Ringer's fluid to 0.05 percent 
 quinine hydrochlorate in Ringer for about one minute. Repeat after 
 
 Fig. 19. — Action of quinine on the frog's heart. The perfusion method was used. 
 Normal rate with Ringer's solution. Strength of quinine 0.05 per cent. Timei in 
 half minutes. 
 
 recovery, using' i percent quinine. Continue this perfusion until no further 
 contractions are secured. Examine the condition of the ventricle at the close 
 of the experiment. 
 
 Vary this experiment by pithing the frog, taking care to lose little blood 
 and making a record from the ventricle.- Now give a lymph sac injection 
 of I c.c. of I percent quinine and take a continuous record through 20 to 
 30 minutes. 
 
 3. Quinine on the striated muscle. Ligate one leg of a frog at 
 the thigh, inject i c.c. of o.i percent quinine into the dorsal lymph sac. 
 In just 20 minutes ligate off the other leg and pith the frog. Determine 
 the irritability, first of the normal then of the drugged muscle. Determine 
 the work each gastrocnemius will do. 
 
ATROPINE. 
 
 33 
 
 ATROPINE. 
 
 Experiments Showing the Action of Atropine. page. 
 
 1. On the frog . 33 
 
 2. On the heart muscle 33 
 
 3. On the frog's heart and on the cardiac nervous apparatus . 34 
 
 4. On the secretory nerves of a mammal 34 
 
 5. On the isolated heart of the cat . . -35 
 
 6. On the circulatory and respiratory systems of the mammal . 35 
 
 7. On the eye 36 
 
 8. On man in the therapeutic dose 36 
 
 9. As secreted by the kidney 36 
 10. Scopolamine on the frog . 36 
 
 I. Atropine on the frog. Give a frog an injection of i c.c. of i 
 percent of atropine sulphate. Keep it under observation in a moist 
 battery jar until complete recovery. The toxic dose is i c.c. of 3 percent. 
 
 Atropine -001^ i^^ 
 
 Fig. 20. — Action of atropine on the heart muscle of the terrapin's ventricle. 
 The normal solution is sodium chloride, the strength of atropine o.ooi percent. The 
 decrease in amplitude is usually not so great as in this tracing, or is even absent entirely 
 Time in seconds. 
 
 2. Atropine on the heart muscle. Mount a ventricular strip from 
 the terrapin in 0.7 percent sodium chloride, and when it is contracting with a 
 uniform amplitude and regular rhythm change to o.ooi percent atropine 
 in physiological saline for five minutes, see figure 17. Recover the charac- 
 teristic rhythm in saline and repeat using 0.002 percent atropine in saline. 
 3 
 
34 
 
 EXPERIMENTAL PHARMACOLOGY. 
 
 3. Atropine on the frog's heart and cardiac nervous apparatus. 
 
 Pith a frog, expose the heart and take a tracing. Determine an effective 
 strength of stimulus for the vagus. Now irrigate the heart for one minute 
 from a dropping bottle containing o.i percent atropine in saline. Stimu- 
 late the vagus immediately and once every five minutes or less. Atropine 
 eliminates the vagus control of the heart by poisoning the peripheral endings. 
 The atropine effect is antagonized by physostigmine, page 44, experiment 3, 
 and by muscarine. 
 
 4. Atropine on the secretory nerves of a manunaL Anesthetize 
 a 10 jkilo dog with morphine and chloroform. Expose and tie a canula in 
 
 Fig. 21. 
 
 I Fig. 2j:. — Action of atropine on the isolated heart of the cat. Locke-blood solution 
 the arrows was .001 percent. Temperature 39° C. Pressure 85 cm. of water. The 
 
 the subinaxillary' duct. Expose and stimulate the chorda tympani nerve 
 in the hilus of the gland, noting the rate of secretion by the drops of saliva 
 per minute from the canula. Give a hypodermic injection of 1.5 c.c. of 
 I percent atropine. Stimulate the chorda tympani nerve again. No 
 secretion is obtained even though the nerve is stimulated down close to the 
 hilys of the gland. 
 
 This demonstration may be made in part as follows: Produce a rapid 
 flow of saliva in the dog by a hypodermic of i c.c. of 0.2 percent pilocarpine. 
 Observe the .flow by turning out the dog's upper lip. Follow with a hypo- 
 dermic dose of I c.c. of I percent atropine. The secretion stops. 
 
ATROPINE. 
 
 35 
 
 5. Atropine on the isolated heart of the cat. Anesthetize a cat 
 with ether. Bleed it and prepare the Locke-blood perfusion fluid. Isolate 
 and suspend the heart in the perfusion apparatus. Obtain a normal record 
 then perfuse with .001 percent atropine in Locke-blood solution. 
 
 6. Atropine on the circulatory and respiratory systems in the 
 mammal. Anesthetize a lo-kilo dog as in experiment 4 preceding. Place 
 an arterial canula in the carotid and insert a tracheal canula. Take a con- 
 tinuous record of the blood-pressure and of the respiration. Stimulate the 
 peripheral end of the sectioned vagus with a stimulus that produces complete 
 inhibition of the heart. Stimulate also the central end of the vagus. Now 
 
 was used for the normal perfusion fluid, 
 time in seconds. 
 
 Fig. 21 (Continued). 
 
 The strength of atropine perfused between 
 
 give an intravenous injection of i c.c. of o.i percent atropine. Note 
 the exact time of the injection on the record by a signal pen. When the 
 equilibrium is again established, re-stimulate the ends of the sectioned vagus 
 with the same strengths of stimulus used before atropine was given. Note 
 that the heart rate is no longer slowed on stimulation of the peripheral 
 vagus, but that the pupil still actively dilates after this dose when the 
 central end of the vagus trunk is stimulated. Atropine also destroys the 
 vagus control over the smooth muscle of the alimentary tract thus decreasing 
 its motihty. 
 
 Physostigmine is an antagonist to atropine. Try i c.c. of o.i percent 
 
36 EXPERIMENTAL PHARMACOLOGY. 
 
 intravenous. Use artificial respiration if necessary. Give a second injec- 
 tion of atropine later. See figure 23 for a reverse antagonism. 
 
 7. Atropine on the eye. Drop i or 2 drops of i percent atropine 
 in the right eye of a dog or cat. The pupil will be widely dilated in a few 
 minutes. Keep the animal under observation until the effect entirely dis- 
 appears, often only after several days. Atropine destroys the power of 
 accommodation and it is used for this clinical purpose in eye practice. 
 Students should not use atropine on their own eyes, but a mild dose of hom- 
 atropine, 2 or 3 drops of i percent, the effect of which passes off in 24 
 to 36 hours, may be tested in one's own eye. In such experiments test the 
 accommodation, light reflex, and size of the pupil. 
 
 8. Atropine on man in therapeutic dose. Test on yourself the 
 action of a dose of 1/120 to 1/60 grain of atropine by way of the mouth. 
 Note the effects on the heart rate, pulse character, respiration, size of pupil, 
 light reflex and sensations. 
 
 9. Atropine is secreted by the kidney. — ^This may be demonstrated 
 on the rabbit which is very tolerant of the drug. Give a rabbit urethane. 
 Collect the urine from a bladder canula. Give a large hypodermic injection, 
 2 c.c. of 2 percent atropine, and test the rabbit's urine on the eye of a cat or 
 dog. The atropine may be extracted (Binz). Concentrate a large amount 
 of urine, add ammonia, shake up with chloroform, evaporate, dissolve the 
 residue and test on the eye of a cat or a dog. 
 
 10. Scopolamine on the frog. Give a dose of i c.c. of i percent 
 scopolamine in the dorsal lymph sac of a frog. Compare with the effects 
 of an equal dose of atropine in experiment i above. 
 
NICOTINE. 37 
 
 NICOTINE. 
 
 Experiments Illustrating the Action of the Nicotine. page. 
 
 1. On the frog. . . -37 
 
 2. On the ventricular muscle. . 37 
 
 3. On the frog's heart and its nervous apparatus. . . 37 
 
 4. On the nerve fiber and on nerve ganglia. . . -37 
 
 5. On the mammalian heart. 38 
 
 6. On the circulatory system and on the respiratory nervous 
 
 mechanism . .... 38 
 
 7. On muscle irritability . . . 39 
 
 1. Nicotine on the frog. Give an injection of a 0.5 c.c. of 0.2 
 percent nicotine into the dorsal lymph sac of a frog. 
 
 2. Nicotine on the ventricular muscle. Prepare a terrapin's heart 
 strip and when it is contracting rhythmically in 0.7 percent physiological 
 saline, immerse the strip in a 0.05 percent solution of nicotine in saline 
 for two minutes, then return to the saline bath. Repeat. If the solution is 
 too strong the strip will exhibit a strong tonus with incomplete relaxations. 
 The amplitude and the rate are markedly increased. 
 
 3. Nicotine on the frog's heart and its nervous mechanism. 
 Pith a frog, expose the heart and take tracings on a drum with a speed of 
 2 mm. per second. Stimulate the vago-sympathetic with an interrupted 
 current that just causes complete inhibitions. Now irrigate the heart from 
 a dropping bottle with o.i percent nicotine in 0.7 percent saline, and 
 stimulate the vagus at intervals of two minutes. If the nerve stimulation 
 ceases to be effective, then apply the electrodes directly to the sinus. 
 
 To demonstrate the stronger effects on heart muscle prepare a second 
 frog. Take a tracing of the heart. Apply a few drops of i percent solu- 
 tion of nicotine. 
 
 4. Nicotine on the nerve ganglia and on the nerve fiber. Anes- 
 thetize a rabbit (or cat or dog), dissect out the cervical sympathetic and 
 the superior cervical ganglion. Stimulations of the nerve or of the ganglion 
 lead to vasoconstriction in the ear and dilation of the pupil. Paint the 
 nerve below the ganglion with i percent nicotine. Stimulation at a point 
 still lower down shows that the nerve impulses still pass undisturbed. 
 Now paint the ganglion itself. Stimulate the nerve below the gangUon, also 
 
38 EXPERIMENTAL PHARMACOLOGY. 
 
 the ganglion directly. What Conclusions ? See also the next experiment. 
 (Ref.: Langley and Dickinson, Journal of Physiol., Volume II, page 265.) 
 5. Nicotine on the mammalian heart. Prepare the mammalian 
 heart perfusion and recording apparatus and bring it to a temperature of 
 36° C. Etherize a cat, bleed, defibrinate the blood, and dilute to one-in-ten 
 of Locke's solution. Quickly take out the heart, suspend it in the apparatus 
 and start the perfusion. When the heart is beating well, perfuse it with 
 o.ooi percent of nicotine in Locke-blood solution. There is a constant 
 
 Fig. 22. — Action of nicotine on the ventricular muscle from the terrapin. The 
 strip was contracting in physiological saline when transferred to 0.2 percent nicotine in 
 saline at the point marked. The solution was too strong and was removed after about 
 forty seconds. Time in seconds and half-minutes. 
 
 sharp increase in amphtude with a more slowly developed increase in 
 rate. The after amplitude may remain greater than the preceding normal. 
 6. Nicotine on the circulatory and respiratory nervous mechan- 
 ism. Anesthetize a dog or cat (the animal used in experiment 4 above 
 may be used for this experiment also). Take a blood-pressure from the 
 carotid and a respiration tracing from the trachea, (i) Determine an effect- 
 ive stimulus for the heart and respiration. (2) Now inject 5 c.c. of o.l 
 percent solution of nicotine into the saphenous or jugular vein. Repeat 
 
NICOTINE. 
 
 39 
 
 the dose if necessary, until distinct effects are produced on the heart rate and 
 blood-pressure. (3) Stimulate the vagus at first with the strength of stimu- 
 lus used before the injection, then with successively stronger stimuli. An 
 instructive picture is obtained by dissecting down to and stimulating the 
 cardiac branches from the annulus of Vieussens, which may be done in 
 the dog on the left side without opening the thorax. 
 
 Fig. 23. — Action of nicotine on the isolated cat's heart. The heart was contract- 
 ing in Locke-blood solution when it was perfused with o.ooi percent nicotine between 
 the points marked by the arrows. The increase in amplitude is more marked when 
 the heart is beating weaker at the time of perfusion. Time in seconds. 
 
 7. Nicotine on muscle irritability. Lay a ligature around the 
 thigh of one leg of a frog and then give i c.c. of o.i percent nicotine 
 in the dorsal lymph sac. After 20 minutes test the irritability of the normal 
 and of the nicotinized gastrocnemius muscles by the minimal and maximal 
 stimulus method. 
 
40 EXPERIMENTAL PHARMACOLOGY. 
 
 CURARE. 
 
 Experiments on the Effect of Curare. page. 
 
 1. On the frog. .... 40 
 
 2. On the motor nerve endings. ... 40 
 ' 3. On the heart muscle and on the cardiac nervous mechan- 
 ism. . 40 
 
 4. Poisons the motor endings before the other portions of the 
 
 reflex arc. . . . . 41 
 
 5. On the mammal. . 41 
 
 1. Curare on the frog. Give a frog a hypodermic of 0.3 c.c. (5 
 minims) of 0.2 percent curare. The motor apparatus is paralyzed, but 
 the circulation continues and the frog will recover in from one to three days, 
 respiration being maintained through the moist skin if the animal is kept in 
 a covered jar. 
 
 2. Curare on the motor nerve endings, Bernard's experiment. 
 The specific action of curare was demonstrated by Claude Bernard to be on 
 the motor nerve end plates. Ligate one leg of a frog to shut off the circula- 
 tion, give a hypodermic of 0.3 c.c. of 0.2 percent curare. When general 
 paralysis is secured, perform the following tests, interpreting the results 
 through the effect on the gastrocnemius muscles: 
 
 a. Stimulate the sciatic nerve on the unligated leg. 
 
 b. Stimulate the gastrocnemius of the unligated side. 
 
 c. Stimulate the sciatic nerve on the ligated side above the ligature. 
 
 d. Below the ligature. 
 
 e. The corresponding muscle. Conclusions. 
 
 3. Curare on the heart muscle and on the cardiac nervous appa- 
 ratus. While minimal doses of curare suffice to poison the motor end plates, 
 it takes relatively large doses to paralyze the cardiac nervous apparatus. 
 The paralysis apparently affects the ganglionic nerve endings first and then 
 the cardiac motor endings and muscle. Pith a frog, expose the heart, pre- 
 pare the vagus trunk for stimulation and adjust a heart lever for record. 
 Allow physiological saline from an irrigating bottle to run over the heart. 
 Take a normal record and then stimulate the vagus nerve. Now irrigate 
 slowly with 0.2 percent curare in saline and stimulate the nerve 10 seconds 
 at a time at intervals of 10 minutes for several tests. 
 
CURARE. 41 
 
 4. Curare poisons the motor endings before the other portions 
 of the reflex arc. Tie a ligature on a frog's leg at the thigh, inject 0.3 
 c.c. of 0.2 percent curare. Just as voluntary activity ceases stimulate the 
 skin of the poisoned leg. The unpoisoned gastrocnemius will contract. 
 Rapidly expose and stimulate the poisoned sciatic. The poisoned gastroc- 
 nemius will not contract, while the unpoisoned one will, owing to reflex 
 stimulation through the cord. 
 
 5. Curare on the mammal. Morphinize and chloroform a dog. 
 Take blood-pressure. Introduce a tracheal canula and take the respiratory 
 record by the intra-tracheal method. Arrange the apparatus for artificial 
 respiration when needed. Inject into a vein 5 c.c. of i percent curare. 
 All movements of voluntary muscles will quickly cease including respiratory 
 movements. The heart rate and the blood-pressure remain good, and if 
 artificial respiration is applied the circulation can be maintained for several 
 hours, or until the drug is eliminated and recovery occurs. 
 
42 
 
 EXPERIMENTAL PHARMACOLOGY. 
 
 PILOCARPINE. 
 
 Experiments Showing the Action of Pilocarpine. 
 
 1. On the frog 
 
 2. On the mammal 
 
 On the ventricular muscle . .... 
 
 3- 
 4- 
 
 5- 
 
 PAGE. 
 ... 42 
 . 42 
 
 43 
 
 On the frog's heart 43 
 
 On the circulatory and respiratory systems of the mammal . 43 
 
 I. Pilocarpine on the frog. Give a frog a hypodermic injection 
 of 0.6 c.c. of 10 percent solution of pilocarpine nitrate. Keep the 
 frog in a moist battery jar until normal again. The toxic dose is I c.c. of 
 10 percent solution of pilocarpine. 
 
 on off 
 
 UjUULjUULIjU 
 
 ir~tnnmrV~nmr- 
 
 nr~nrnnnrir~nr 
 
 Fig. 24. — Blood-pressure and respiratory effects of an intravenous injection of i 
 c.c. of I percent pilocarpine in the dog. Injection between the points "on" and 
 "off." Time in seconds. Pressure in mercury. Reduced to four-fifths the original size. 
 
 2. Pilocarpine on the mammal. Give a dog a hypodermic injection 
 of 0.3 c.c. (5 minims) i percent pilocarpine. This dose produces a 
 marked secretion by glandular structures. Examine the flow of saliva by 
 turning back the upper lip, drying it and noting the accumulation of drops 
 
PILOCARPINE. 43 
 
 at the mouth of the salivary duct. An injection of i c.c. of o.i percent 
 atropine in a vein antagonizes pilocarpine and stops the secretion. 
 
 Give additional drops of i percent pilocarpine in the eye. Drops 
 of I percent atropine on the eye will overcome the action. 
 
 3. Pilocarpine on the ventricular muscle. Mount a strip of the 
 terrapin's ventricle in physiological saline. When the contractions are 
 regular transfer to a o.i percent pilocarpine solution in saline. Allow it 
 to act only i minute then renew the physiological saline bath. As a final 
 test give the strip a continuous bath of 0.1 percent pilocarpine and note 
 the successive effects. 
 
 4. Pilocarpine on the frog's heart. Pith a frog, expose the heart 
 and take tracings of the ventricle. Test the activity of the vagus with a 
 strong interrupted current. Now irrigate the surface of the heart with 
 drops of I percent pilocarpine for two minutes. Stimulate the vagus trunk 
 one minute after pilocarpine and at successive intervals of five minutes. If 
 the drug is strongly active the heart will beat slower. In the early stages 
 the stimulation will result in acceleration, but in no inhibition as in the 
 normal. Applying the electrodes directly to the sinus gives no inhibition 
 showing that the pilocarpine has acted on the vagus endings and not on the 
 ganglionic connections. Drops of i percent atropine sulphate will restore 
 the heart beat after pilocarpine, these two drugs being antagonists. 
 
 5. Pilocarpine on the circulatory and respiratory system of the 
 mammal. Anesthetize a dog with morphine and chloroform. Introduce a 
 tracheal canula and be prepared to use artificial respiration if necessary. 
 Take blood-pressure and respiration records on a continuous paper kymo- 
 graph. Test the activity of the vagus. Give an intravenous injection of 
 I c.c. of I percent pilocarpine nitrate. Retest the activity of the vagus 
 after the pilocarpine. Atropine antagonizes the pilocarpine effect. Ex- 
 amine the pupils from time to time. Also note the increased rate of salivary 
 secretion. 
 
44 EXPERIMENTAL PHARMACOLOGY. 
 
 PHYSOSTIGMINE. 
 
 Experiments on the Action of Physostigmine. page. 
 
 1. On the frog ... . . 44 
 
 2. On cardiac muscle . . 44 
 
 3. On the frog's heart and its nervous apparatus . . . . 44 
 
 4. On the heart of the cat ... 44 
 
 5. On the respiratory medullary center and on the circulatory 
 
 system of the mammal . . .... 44 
 
 6. On the eye . . . . 47 
 
 1. Physostigmine on the frog. Give a frog a dorsal lymph sac 
 injection of i c.c. (17 minims) i percent physostigmine. The effects 
 produced are diminished irritability, loss of muscular tone, paralysis of the 
 respiratory center, loss of reflexes, and death, or, at best, a very slow and 
 prolonged recovery. 
 
 2. Physostigmine on cardiac muscle. After a ventricular strip 
 from the terrapin has begun beating regularly in physiological saline, transfer 
 it to o.i percent physostigmine in saline for two to three minutes. Physi- 
 ological saline recovers the normal contractions after several minutes. 
 Compare the results with those from pilocarpine and muscarine. A bath of 
 0.002 percent atropine antagonies the physostigmine effects. 
 
 3. Physostigmine on the frog's heart and its nervous apparatus. 
 Pith a frog and take a record of the heart beat. Determine the minimal 
 effective stimulus of the vagus trunk for inhibition of the heart rate. Now 
 irrigate the surface of the heart with drops of o.i percent physostigmine 
 from an irrigating bottle for two minutes. Redetermine the minimal stimulus 
 for the vagus trunk beginning with a very weak induction current. If 
 the contractions are at a slow rate or have ceased, irrigate the surface of the 
 heart with i percent atropine. Atropine antagonizes physostigmine. 
 Compare with pilocarpine. If the perfusion method is used then 0.0 1 
 percent physostigmine is the proper solution strength for the frog's heart. 
 
 4. Physostigmine on the isolated heart of the cat. Prepare an 
 isolated cat's heart by the method used in the nicotine experiment 5. When 
 it gives regular contractions, perfuse it with o.oi percent physostigmine 
 in Locke-blood solution. 
 
 5. Physostigmine on the respiratory medullary center and on 
 the circulatory system of the mammal. Anesthetize a dog, insert a trach- 
 
PHYSOSTIGMINE. 
 
 45 
 
46 
 
 EXPERIMENTAL PHARMACOLOGY. 
 
 eal canula and be prepared for artificial respiration. Take a continuous 
 record of the blood-pressure and of the respiratory movements. Insert a 
 canula in the saphenous vein and connect it with a buret containing the drug. 
 Give an intravenous injection of o.i percent physostigmine slowly until the 
 first effects are noticed on blood-pressure. Note the amount and mark 
 the time of the dose on the record by a signal pen. Usually there is a pro- 
 
 lljUUUlJUUlJUlJUUUUUUJJlJlJUlJUlJUlJlJUUlJlJ^ 
 
 XT 
 
 Fig. 26. 
 
 Fig. 26. — Action of physostigmine and its antagonism by atropine in the mammal, 
 showing the effects of an injection of 8 mgr. of physostigmine just before the part of 
 of respiration and the circulation effects upon the injection of 2 mgr. of atropme be- 
 At a, b and c are shown portions of the trace at 30-second intervals. Time in seconds. 
 
 gressive paralysis of the respiratory center accompeinied by a great slowing 
 of the heart and a fall of blood-pressure by one-half or more. The heart 
 continues to beat long after respiration ceases. Use artificial respiration 
 until the blood-pressure improves' and the anesthesia becomes Hght. This 
 will not restore automatic respiratory movements as it does after heavy 
 anesthesia. If at this time a venous injection of 0.5 c.c. of i percent 
 
PHYSOSTIGMINE. 
 
 47 
 
 atropine be given from a hypodermic syringe the respiratory movements 
 will be quickly established and the slow heart and low pressure will give 
 way to the rapid heart and strong pressure following primary injection of 
 atropine, experiment 6, page 35. The vagus inhibitory apparatus is effective 
 under physostigmine, but not after atropine. Repeat the experiment. It 
 takes a larger dose of physostigmine to overcome the atropine and pro- 
 
 j|||KWij|^^ 
 
 
 I ' I j^ i 
 
 > 1 1 1 1 1 1 1 
 
 3 b 
 
 Fig. 26 (Continued). 
 
 Parts I, iX and iT give the respiration trace, blood-pressure and time, respectively, 
 the trace shown. The parts of the trace numbered 2, 2X and 2T show the recovery 
 tween the arrows. A few second's gap intervenes between the two parts of the figure. 
 
 duce the characteristic effects. Examine the pupil before and after the 
 physostigmine. 
 
 6. Physostigmine on the eye. Give 2 drops of i percent phy- 
 sostigmine in one eye of a dog or a rabbit, at intervals of five minutes. It 
 is better to use one of the experimeter's own eyes. Strong contraction of 
 the pupil follows. A decrease in intraocular pressure has also been proven, 
 
48 EXPERIMENTAL PHARMACOLOGY. 
 
 and to produce this effect is the chief therapeutic use of the drug. A strik- 
 ing comparison is obtained by dropping i percent atropine in the unused 
 eye of the dog after the physostigmine effect has come on in the other eye. 
 Physostigmine will overcome the atropine dilation of the pupil. The experi- 
 menter may show the antagonism between homatropine and physostigmine 
 on his own eyes, but it is recommended that one eye always be reserved. 
 
 ACONITE. 
 
 Experiments on the Action of Aconite. page. 
 
 1. On the frog 48 
 
 2. On the circulatory system of a mammal. 48 
 
 3. On the frog's heart 48 
 
 4. On the mammalian heart. . . . 48 
 
 1. Aconite on the frog. The dose is 0.5 c.c. of o.i percent aconite. 
 
 Compare with digitalis. 
 
 2. Aconite on the circulatory system of the mammal. Take a 
 continuous tracing of the blood-pressure of a dog. Give i c.c. of o.i 
 percent aconitine crystals. Note particularly the progressive effects on 
 the nervous and muscular elements of the circulatory apparatus. 
 
 3. Aconite on the frog's heart. Destroy the cerebrum and optic 
 lobes only of a frog, -expose the ventricle and take a tracing. Give an in- 
 jection of 0.5 c.c. of O.I percent aconitine in the lymph sac. One may 
 expect a progressive stimulation of the accelerator and vagus nervous 
 apparatus followed by paralysis of nerves and muscle. 
 
 4. Aconite on the mammalian heart. Prepare an isolated heart 
 as described for the nicotine experiment 5. When the heart is contracting 
 regularly with the Locke-blood perfusion then perfuse for 10 seconds with a 
 0.0002 percent aconite solution. A prolonged perfusion or perfusion 
 with a stronger concentration of aconite will quickly set up incoordinate 
 contractions and fibrillation. 
 
ACONITE. 
 
 49 
 
 XI 
 
 S 
 
 a, 
 a 
 o 
 
 
50 EXPERIMENTAL PHARMACOLOGY. 
 
 VERATRINE. 
 
 Experiments on the Action of Veratrine. page. 
 
 1. On the frog. . .' . . -5° 
 
 2. On the mammal. . .... 50 
 
 3. Veratrine on heart strip. . . . 50 
 
 4. On the frog's heart. . . . 50 
 
 5. On the isolated mammalian heart. ... 50 
 
 6. On the form of the simple muscle contraction 50 
 
 7. On the circulatory and respiratory systems of the mammal. . 50 
 
 1. Veratrine on the frog. The dose for a frog is about 0.5 c.c. 
 of a I percent solution of the fluid extract veratrum viride or 0.3 c.c. of 
 o . 1 percent veratrine . Compare with the effects of aconite and of barium. 
 See experiment 4. 
 
 2. Veratrine on the mammal. Give a cat or rabbit i c.c. of o.i 
 percent veratrine hypodermically, or i c.c. of i percent for a dog. Keep 
 under observation for a considerable time. 
 
 3. Veratrine on the heart strip. Subject the contracting strip of 
 ventricle to 0.005 to 0-05 percent vera tine in sahne. 
 
 4. Veratrine on the frog's heart. Pith a frog, expose the heart and 
 take a tracing when perfused with 0.005 percent veratrine in Ringer's 
 solution (o.oi percent destroys coordination). 
 
 5. Aconite on the isolated mammalian heart. Prepare the appara- 
 tus for the isolated heart experiment, isolate a cat's heart and perfuse with 
 0.0002 percent veratrine in Locke-blood solution. See Fig. 25. 
 
 6. Veratrine on the simple muscle contraction of the frog. Ligate 
 one leg of a frog and give a hypodermic of 0.5 c.c. of o.i percent vera- 
 trine. After 15 minutes prepare the veratrinized muscle and take simple 
 muscle contractions to show the form of the contraction wave, using a 
 tuning fork to record the drum speed. Compare this curve with that of 
 the undrugged muscle. 
 
 The frog of experiment i may be used to show the veratrine effect on 
 muscle work. Stimulate once in three seconds in this experiment, since the 
 relaxation may not be complete in an interval of two seconds. 
 
 7. Veratrine on the circulation and respiration of a mammal. 
 Take a record of the blood-pressure from the carotid of an anesthetized dog. 
 Tracheotomize and take respiratory tracings. Give i c.c. of i percent 
 veratrine in the abdominal cavity. When marked cardiac slowing appears 
 cut the vagi and note the effects on the heart. 
 
VERATRINE. 
 
 51 
 
52 EXPERIMENTAL PHARMACOLOGY. 
 
 DIGITALIS. 
 
 Experiments Showing the Action of Digitalis. page. 
 
 1. On the frog. ... 52 
 
 2. On the ventricular muscle. ... . . . 52 
 
 3. On the frog's heart. . . 52 
 
 4. On the atropinized frog's heart. . 52 
 
 5. On the mammalian heart . . . 52 
 
 6. On the circulatory and respiratory systems of the mammal. 53 
 
 7. Digitalis as a diuretic 53 
 
 1. Digitalis on the frog. Give a dose of 0.5 c.c. of 0.2 percent 
 of soluble digitalis. The digitalis effects develop slowly. Note the heart 
 rate, and particularly the circulation in the web. Keep in a moist battery 
 jar for at least two hours. Examine the heart if death occurs. 
 
 2. Digitalis on the ventricular muscle. Treat a strip of terrapin's 
 ventricle contracting in saline to a bath of 0.002 percent digitalis in saline. 
 Follow with pure saline. Repeat with a 0.005 percent digitalis. Still 
 stronger solutions may be used, but a marked tone will result as shown in 
 Figure 26. 
 
 Digitalis solutions may be used made up in the weaker Ringer, but 
 as the rate is slower and the amplitude much greater than that in sodium 
 chloride solutions the picture will be quite different, though the same in 
 kind. Delirium cordis of the strip is produced by the stronger solutions act- 
 ing for several minutes. 
 
 3. Digitalis on the frog's heart. Pith a frog and take a record of 
 the contractions of the ventricle when irrigated with physiological saline. 
 Irrigate slowly with drops of 0.2 percent digitalis for two minutes, then 
 wash off with saline. 
 
 A more effective method is to perfuse the heart from a canula in the 
 vena cava. Use a much weaker solution for perfusion, i.e., 0.0005 to 
 o.ooi percent digitalis in Ringer. These effects should be compared with 
 the effects on cardiac muscle above. 
 
 4. Digitalis on the atropinized frog's heart. Atropinize the frog's 
 heart to eliminate the car'diaic nervous control, then repeat experiment 3 
 above. 
 
 5. Digitalis on the mammal heart. Use the method described 
 on page 70. Isolate and perfuse the cat's heart with the normal solution 
 
DIGITALIS. 
 
 53 
 
 of Locke-blood, then with o.oooi percent digitalis (soluble digitalis) 
 in Locke-blood. Increase the strength to 0.0005 percent. The stronger 
 solution will usually produce a great increase in amplitude followed by 
 fibrillation. The weaker solution, see figure 30, produces a typical mild 
 therapeutic effect on the heart. Compare with the results of experiment 6. 
 6. Digitalis on the circulatory and respiratory systems of the 
 mammal. Anesthetize a dog and take continuous kymographic records 
 of the blood-pressure and of the respiration. Slowly inject into the saphe- 
 nous vein 2 c.c. doses of 0.5 percent digitalis at five-minute intervals 
 
 Digitalis o.oe^ 
 
 Fig. 29. — Experiment showing the action of digitalis on the rhythm and tone of a 
 strip of terrapin's ventricle. The strip was contracting in physiological saline. Between 
 the words "on" and "off" it was subjected to 0.06 percent of digitalis in saline. 
 
 until the three stages of digitalis effect on the heart and blood-pressure are 
 obtained. The anesthetic must be perfectly constant. One may give the 
 maximal dose of 4 c.c. of i percent digitalis at once. In this instance the 
 three stages are passed through rapidly and the animal will usually die in 
 10 to 20 minutes. Read Cushny's Pharmacology, pp. 430-435. 
 
 7. Digitalis as a diuretic. Morphinize and chloroform a dog. 
 Take the blood-pressure. Isolate the ureters near the bladder and insert 
 canulas, using care not to occlude the ureters by twisting or otherwise. Con- 
 nect the ureters by means of a T-tube with a horizontal 2 c.c. pipet graduated 
 
54 
 
 EXPERIMENTAL PHARMACOLOGY. 
 
ERGOT. 55 
 
 to 1/50 c.c. Close the abdomen with sutures. Insert a venous canula and 
 connect with a transfusion buret. Establish the normal secretion per 10 
 minutes, cutting off the column of secreted urine by injecting a bubble of air 
 into the mouth of the buret by inserting a hypodermic needle through the 
 rubber connecting tube. Now inject 5 c.c. of o.i percent digitalis or 
 strophanthin into a vein and take the secretion in successive 10 minute 
 periods until the flow is constant. Repeat the dose once or twice at long in- 
 tervals. Mark the secretion intervals on the blood-pressure record. 
 
 Compare these results with those observed on other diuretic drugs — 
 caffeine, urea, inorganic salts, etc. 
 
 ERGOT. 
 
 Experiments on the Action of Ergot. page. 
 
 1. On the frog 55 
 
 2. On the heart muscle. 55 
 
 3. On the arterioles of the frog. 55 
 
 4. On the blood-pressure and heart rate of a mammal. 55 
 
 1. Ergot on the frog. Give 0.5 c.c. of the fluid extract. 
 
 2. Ergot on the heart muscle. Change a contracting heart strip 
 from saline to a i o percent solution of Squibbs' fluid extract of ergot in saline 
 solution. Allow it to act for five minutes. Take a continuous record. 
 
 3. Ergot on the arterioles of the frog's web. Wrap a frog in 
 a wet cloth and fasten to a frog-board for examining the web. Give a 
 lymph sac injection of 0.5 c.c. fluid extract of ergot. Select a good field 
 of small arterioles and measure their diameter at once. The relative 
 change in diameter of small vessels can be determined by selecting a field 
 in which pigment spots mark the borders of the vessels. Sketch such a 
 vessel and spots for the normal. Re-sketch after the drug. Re-measure at 
 intervals of five minutes as the ergot is absorbed. 
 
 4. Ergot on the blood-pressure of a mammal. Give an intravenous 
 dose of 0.5 c.c. fluid extract of ergot to a mammal while taking a record 
 of the blood-pressure. 
 
56 EXPERIMENTAL PHARMACOLOGY. 
 
 SUPRARENAL GLAND. 
 
 The commercial preparation of the active principle of suprarenal gland, 
 adrenalin hydrochloride, presents the same physiological action as the gland 
 extract and has the special advantage of preparation in definite and known 
 strengths. It has come into general use for therapeutic purposes and is, 
 therefore, used in these experiments. 
 
 Experiments Showing the Action of Adrenalin Hydrochloride, page. 
 
 1. On the frog. 56 
 
 2. On the ventricular strip 56 
 
 3. On the frog's heart 56 
 
 4. On the isolated mammalian heart .... -56 
 
 5. On the simple muscle contraction . 58 
 
 6. On muscle work . . • 58 
 
 7. On the local mucous surfaces . . 58 
 
 8. On the size of the blood-vessels in the frog's web 58 
 
 9. On general blood-pressure and peripheral vaso-constriction 58 
 
 1. Adrenalin on the frog. Give 0.5 c.c. o.i percent in the dorsal 
 lymph sac. 
 
 2. Adrenalin on the ventricular muscle. Transfer a terrapin's 
 ventricular strip contracting in physiological saline to o.oi percent adren- 
 alin in saline. Change after two to five minutes. The drum speed should 
 be I cm. per minute. Suprarenal extract has also been shown to increase 
 the amplitude and the rate of the ganglion free ventricular muscle of the 
 dog. Cleghorn, Amer. Jour. Physiol., Volume III, p. 273. 
 
 3. Adrenalin on the frog's heart. Use the perfusion method, page 
 68, with the heart in place and the inflow canula in the ascending vena cava. 
 Follow physiological Ringer perfusion with o.ooi percent adrenalin 
 hydrochloride in Ringer. The drum speed should be 2 mm. per second. 
 Direct application to the surface of the heart requires a strength of at least 
 0.05 percent adrenalin hydrochloride. 
 
 4. Adrenalin on the isolated heart. Perfuse a cat's heart in the 
 usual way with Locke-blood solution for a normal, then change to a o.oooi 
 percent adrenalin hydrochloride in Locke-blood. If the heart be beating 
 feebly it often happens that the contractions will increase in amplitude by 
 200 percent and more. 
 
SUPRARENAL GLAND. 
 
 57 
 
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 ■t 8 
 
 wj 
 
 tn 
 
 
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 V oi 
 
 ^^ 
 
 ^ CO 
 
 <u o 
 
 -^ J-- 
 
 o '^ 
 
 o ^ 
 
 'S '^ 
 
 O cj 
 
 O l^ 
 
 T3 CL, 
 
 O ^ 
 
 
58 EXPERIMENTAL PHARMACOLOGY. 
 
 5. Adrenalin on the simple muscle contraction. Ligate one leg 
 of a frog and give 0.5 c.c. of 0.05 percent adrenalin. Allow ten minutes 
 for absorption. Compare the simple muscle contractions of the two gastroc- 
 nemii as repards a, amplitude, and b, the time of the simple contraction. 
 The muscular power of patients with Addison's disease has also been shown 
 to be greatly improved by giving the extract of suprarenal gland. 
 
 6. Adrenalin on muscle work in the frog. Prepare a frog as in 
 experiment 5 above and test the work performed by the two muscles. For 
 details of procedure see alcohol experiment 5. 
 
 7. Adrenalin on mucous surfaces. Paint one-half the tongue with 
 0.1 percent adrenalin hydrochloride. At intervals of five minutes drop 
 0.0 1 percent in saline (sterilize by boiling) in one eye. Compare the two 
 halves of the tongue and the two eyes as to vascular condition. Examine 
 the size of the pupils. Test for possible differences as to the sensitiveness 
 of the conjunctiva. Try the effect in the eye of a cat or dog. 
 
 8. Adrenalin on the size of the blood-vessels of the frog's web. 
 Use a dose of 0.5 c.c. of o.i percent as a hypodermic. See ergot experi- 
 ment 3, page 55; nitroglycerine experiment 3, page 59. Or apply drops of 
 o.i percent directly to the web under the microscope. 
 
 9. Adrenalin on general blood-pressure and on vaso-constriction 
 in a manunal. Prepare a dog for blood-pressure. Adjust an onkometer 
 to the left kidney and record the change in volume with a Brodie's bellows 
 or Roy's piston recorder. Give 2 to 4 c.c. of o.oi percent adrenalin 
 hydrochloride slowly in a vein. Give 2 c.c. of 0.1 percent atropine to 
 eliminate the vagus action on the heart and repeat the adrenalin. Compare 
 with digitalis, page 53; ergot, page 55; veratrine, page 50. Drugs of 
 antagonistic action are nitrites and potash salts. 
 
NITROGLYCERINE AND THE NITRITES. 59 
 
 NITROGLYCERINE AND THE NITRITES, 
 
 Experiments on the Action of Nitroglycerine and the 
 
 Nitrites. page. 
 
 1. On the frog. 59 
 
 2. On the heart muscle. . 59 
 
 3. On the arterioles of the frog 59 
 
 4. On the circulation volume 59 
 
 5. Amyl nitrite on the pulse . 59 
 
 6. Nitrites on mammalian blood-pressure . 60 
 Nitroglycerine and the nitrites affect primarily the peripheral circu- 
 lation, causing vaso-dilation with fall of blood-pressure. The specific action 
 is on the muscular tissue. 
 
 1. Nitroglycerine on the frog. Give a frog a dose of 0.5 c.c. of 
 o.i percent nitroglycerine in the dorsal lymph sac. 
 
 2. Sodium nitrite on the heart muscle. Test the action of 0.02 
 percent sodium nitrite on the contracting ventricular strip. 
 
 3. Nitroglycerine on the arterioles of a frog. Bind a frog for the 
 microscopic examination of the web circulation. Then give i c.c. of o.i 
 percent nitroglycerine in the lymph sac. Immediately measure the 
 smaller arterioles in a favorable field and re-examine every two minutes as 
 absorption progresses. Try direct application of drops of 0.1 percent to the 
 web. 
 
 4. Sodium nitrite on the circulation volume. Pith a frog or small 
 terrapin. Insert a canula in the aorta or one of its branches, snip the 
 veins with the scissors to allow free perfusion, set the frog-board at an angle 
 to facilitate drainage of liquid. Perfuse the blood-vessels with a weaker 
 Ringer's solution for a normal. Follow with o.oi percent soditun nitrite 
 in the weaker Ringer, keeping a uniform pressure of the perfusion liquids 
 of from 6 to 10 cm. Measure the perfusion rate in drops per minute, or 
 collect the outflow in a 25 c.c. graduate. 
 
 Test the amount of outflow when irrigated with 0.0005 percent of 
 soluble digitalis, then follow with o.oooi percent sodium nitrite, both in the 
 weaker Ringer. 
 
 5. Amyl nitrite on the pulse. Take normal pulse records with one of 
 the standard sphygmographs. Break an amyl nitrite pearl on a handkerchief 
 and breathe deeply the fumes. Pulse tracings taken 5 and 10 minutes later 
 will show the usual signs of dilated blood-vessels with accompanying low 
 pressure. Slight headaches sometimes follow the use of amyl nitrite. 
 
6o 
 
 EXPERIMENTAL PHARMACOLOGY. 
 
 6. Nitrites on mammalian blood-pressure. Anesthetize a lo kilo 
 dog and take the blood-pressure. Give intravenous doses of nitrites in the 
 following order, repeating with larger doses if necessary and always allowing 
 full time for recovery: i c.c. of o.i percent nitroglycerine, 3 c.c. of o.i 
 percent; 2 c.c. of 0.1 percent amyl nitrite; 6 c.c. of 0.1 percent 
 
 Fig. 32. — Action of amyl nitrite on the human pulse. One amyl nitrite pearl was 
 crushed on a handkerchief and the fumes inhaled deeply. Trace i is the normal pulse. 
 Trace 2 immediately after amyl nitrite fumes. Traces 3 and 4 are stages of recovery. 
 Time in seconds. 
 
 sodium nitrite. The blood-pressure remains low for a long time after 
 sodium nitrite. A dose of 2 c.c. to 5 c.c. of 0.2 percent digitalis or 2 c.c. 
 of o.oi percent adrenalin hydrochloride will antagonize this effect. 
 
 Give 2 c.c. of O.I percent atropine to eliminate the action of the car- 
 diac nervous apparatus and repeat the above doses of nitroglycerine and 
 sodium nitrite. 
 
CARBOLIC ACID. 6l 
 
 CARBOLIC ACID. 
 
 Experiments on the Action of Carbolic Acid. page. 
 
 1. On the frog. . . 6i 
 
 2. On the growth of yeast and bacteria . . . . . 6i 
 
 3. On the circulatory and respiratory systems of a mammal 61 
 
 1. Carbolic acid on the frog. Give a dose of i c.c. of i percent. 
 
 2. Carbolic acid on the growth of yeast and of bacteria. Prepare 
 six fermentation tubes of active yeast culture and as many test-tubes of 
 inoculated bouillon. Keep one tube of each for a normal and to the others 
 add enough 10 percent carbolic acid to make a series of o.i, 0.5, i, 2, and 
 4 percent solutions. Keep at laboratory temperature and observe through a 
 period of several days. 
 
 3. Carbolic acid on the circulatory and respiratory systems of the 
 mammal. While taking records of blood-pressure and respiration by the 
 usual method give an intravenous injection of 10 c.c. of 0.5 percent carbolic 
 acid. When the collapse stage is far advanced inject i percent soditmi 
 sulphate slowly. Judge the amount required by the action in overcoming 
 the carbolic acid depression of the respiratory apparatus. 
 
 POTASSIUM SALTS. 
 
 Experiments Showing the Action of Potassixmi Salts. page. 
 
 1. On the heart muscle ,61 
 
 2. On the reaction time in the reflex frog. . . 61 
 
 3. On muscle irritability and muscle work in the frog . . 61 
 
 1. Potassium chloride on the heart muscle, A ventricular strip 
 contracting in physiological saline solution is transferred to 0.06 percent 
 potassium chloride in saline for two to five minutes. Contractions return 
 in saline even after stronger doses of potash. 
 
 2. Potassium bromide on the reaction time in the reflex frog. 
 Compare the reaction time of a reflex frog before and 20 to 40 minutes after 
 0.3 c.c. of 5 percent potassium bromide in the dorsal lymph sac. 
 
 3. Potassitxm chloride on muscle irritability and muscle work 
 in the frog. Compare the two gastrocnemii as to irritability and as to 
 amount of muscular work done. Dose 0.3 c.c. of 5 percent solution given 
 hypodermic after one leg is ligatured. 
 
62 
 
 EXPERIMENTAL PHARMACOLOGY. 
 
 CALCIUM SALTS. 
 
 Experiments Illustrating the Action of Calcium Salts. p'Age. 
 
 1. On heart muscle 62 
 
 2. On the frog's heart . . 62 
 
 3. On the blood-pressure and the respiration in the mammal. 63 
 
 I. Calcium chloride on heart muscle. Transfer a ventricular strip 
 from physiological saline to 0.03 percent calcium chloride in saline for 
 three to five minutes. Record on a drum speed of 2 cm. per minute. 
 Repeat, using 0.06 percent. The rate is increased and the amplitude often 
 
 Fig. 33. — Terrapin's heart muscle as influenced by a solution of 0.06 percent cal- 
 cium chloride in physiological saline. A weaker solution produces much less tone. 
 Time in seconds. 
 
 doubled. The stronger solution produces great increase in tone which 
 sometimes passes into delirium cordis. Potash salts antagonize. Read 
 Ringer, Jour. Physiology, 1883. 
 
 2. Calcium chloride on the frog's heart. Perfuse the frog's heart 
 through the vena cava with 0.7 percent sodium chloride and follow with 
 0.03 percent calcium chloride in 0.7 percent sodium chloride. Recover 
 
BARIUM SALTS. 63 
 
 the sodium chloride type of contractions, then perfuse with o.oi percent 
 barium in sodium chloride. 
 
 3. Calcium chloride on the blood-pressure and the respiration 
 in the mammal. Give an intravenous dose of lo c.c. of i percent for a 
 dog. Cut the vagi and repeat the dose. Alternate the dose with potassium, 
 2 to 4 c.c. of I percent. 
 
 BARIUM SALTS. 
 
 Experiments on the Action of Barium Salts. page. 
 
 1. On the frog . . 63 
 
 2. On the heart muscle 63 
 
 3. On the circulation and on the respiration movements in 
 
 mammals . . ..... 63 
 
 1. Barium on the frog. Dose, i c.c. of i percent barium chloride. 
 
 2. Bariimi chloride on the heart muscle. Transfer a contracting 
 ventricular strip from 0.7 percent sodium chloride to o.oi percent bariiun 
 chloride in saline. Short immersions increase the rate, but long baths show 
 that this salt does not sustain contractions as do calcium salts. A o.i percent 
 solution in saline delays contractions with prevention of relaxation. Con- 
 tractions still take place in i percent barium chloride. Compare with 
 digitalis. 
 
 3. Baritmi chloride on the circulation and on respiratory move- 
 ments in mammals. The effect on the heart and blood-pressure and on 
 respiration in a mammal is demonstrated by an intravenous dose of 5 c.c. 
 of 0.2 percent given slowly. This dose should be repeated several times 
 both before and after section of the vagi. Barium salts act as strong poisons 
 to the nerve centers, especially those in the medulla. 
 
OPERATIONS, APPARATUS AND SPECIAL 
 METHODS. 
 
 PHYSIOLOGICAL SOLUTIONS. 
 
 The lymph and blood plasma in which the tissues develop are the true 
 physiological solutions. 
 
 Artificial solutions imitate lymph in its isotonicity — ^its physical character, 
 and in its composition — its chemical character. Sodium chloride in 0.6 per- 
 cent solution, used first by Nasse in 1869 on frog's muscle, and by Bow- 
 ditch in 1871 on the frog's heart, was supposed to prevent injurious changes 
 in the tissue by virtue of its isotonicity. Ringer in 1883 and Locke in 1885 
 introduced the solutions which bear their names. They showed that the 
 chemical factors play a fundamental part in the effects of these solutions 
 on the tissues. At the present time we recognize that exact isotonicity is not 
 nearly so fundamental as at first supposed, and that these solutions are 
 chemically active in relation to the living protoplasm. 
 
 At the present time much attention 'is being given to the effects of 
 asphyxiation on the physiological activity of living tissues that are isolated 
 from the normal circulation. The artificial solutions can be made more 
 efficient by shaking with air before using, or by shaking with pure oxygen. 
 Isolated mammalian hearts give much more constant characters in their 
 response to artificial solutions which contain defibrinated blood, prefer- 
 ably from the animal supplying the heart. Even with five to ten percent of 
 blood such solutions are strikingly more efficient, supposedly because they 
 are much better oxygen carriers. For cats' hearts Locke-blood solutions 
 aerated by a stream of oxygen are very efficient indeed. 
 
 1. Physiological salt solution or normal saline. Sodium chloride 
 in distilled water 0.7 percent. More exact isotonicity is secured by 0.6 
 percent for frogs, 0.7 percent for terrapin and 0.9 percent for mammals. 
 
 2. Ringer's solution. The Ringer's solution that imitates the blood 
 serum in its effects on heart tissue is made up in this laboratory in the 
 following proportions: 
 
 Sodium chloride, 0.7 percent. 
 Potassium chloride, 0.03 percent. 
 
 64 
 
ANESTHESIA. 65 
 
 \ Calcium chloride (cryst. computed water free), 0.026 percent. 
 For heart work where a more rapid rate is desired the amount of potas- 
 sium must be reduced to that in Ringer's original formula. 
 Sodium chloride, 0.7 percent. 
 Potassium chloride, o.oi percent. 
 Calcium chloride (cryst. computed water free), 0.026 percent. 
 
 3. Locke's solution. Locke's solution is a mixture of the salts in 
 Ringer's solution with dextrose added to make o.i percent. 
 
 Sodium chloride, 0.7 percent. 
 Potassium chloride, 0.03 (or o.oi) percent. 
 Calcium chloride (cryst), 0.026 percent. 
 Dextrose, o.i percent. 
 
 4. Locke-blood solution. . Add 5 to 10 percent of defibrinated whole 
 blood to the above Locke's solution. 
 
 ANESTHESIA. 
 
 The mammals usually available for laboratory experimental purposes 
 are dogs, cats, rabbits and guinea-pigs, each of which can best be anesthe- 
 tized by a special treatment of its own. 
 
 Dogs. Give a lo-kilo dog i c.c. (17 minims) of 2 percent mor- 
 phine under the skin of the shoulder, holding its head firmly between the 
 operator's legs while the hypodermic injection is being given. Allow 15 
 minutes or more for the morphine to take effect. The morphine should be 
 followed by chloroform or chloroform and ether in equal parts. Give it 
 by means of a small nose hood made by sewing a cheese-cloth, that has been 
 folded in the form of a blunt cone, to a wire ring, or use a Senn's inhaler 
 mask. When the voluntary movements have about ceased, tie the dog to a 
 holder and take it to the experimental table. The tests of good anesthesia 
 are: i, loss of voluntary movements; 2, no cutaneous reflexes; 3, slight 
 corneal reflexes or none in deep anesthesia ; 4, even and fairly deep respira- 
 tion; 5, medium blood-pressure and pulse. This condition of anesthesia 
 is maintained by giving chloroform from a dropping-bottle at abso- 
 lutely regular intervals of 30 seconds by the watch. The number of 
 drops necessary for each animal will quickly be found by trial. In the 
 experience of this laboratory it is from 3 to 6 drops per 30 seconds. The 
 success of most pharmacological experiments on dogs depends upon main- 
 taining an absolutely even anesthesia. 
 
 Cats. A mixture of equal parts of chloroform and ether is the most 
 5 
 
66 EXPERIMENTAL PHARMACOLOGY. 
 
 practical anesthetics for cats. These animals are anesthetized most conven- 
 iently by putting them in a box of about two cubic feet in dimension and 
 provided with a close cover. A very convenient box is the tin display 
 cracker box with glass window obtained of the grocer. Drop in the box with 
 the cat a small strip of cheese-cloth saturated with chloroform-ether mix- 
 ture, ID c.c. in broken doses will anesthetize a cat in lo minutes. As 
 soon as the animal falls down under the influence of the anesthetic it 
 should be taken from the box, fixed in the holder, and the anesthetic given 
 from a cloth in the manner and with care prescribed above for the dog. 
 Cats do not survive pure chloroform in the hands of the ordinary student 
 anesthetist. 
 
 Rabbits. Give rabbits 2 grains of urethane by the mouth. Follow 
 with light and careful use of ether. Or pure ether may be given without the 
 urethane. Give the ether in the manner and with the regularity recom- 
 mended above for giving chloroform to dogs. Do not use chloroform or 
 even chloroform mixtures with rabbits. 
 
 Guinea-pigs. These little animals when they must be used for 
 pharmacological purposes are anesthetized best with pure ether or ether 
 followed with a little morphine. 
 
 THE PREPARATION OF THE VENTRICULAR MUSCLE. 
 
 Destroy the brain of a terrapin, remove the plastron and open the peri- 
 cardium. Grasp the left angle of the base of the exposed ventricle with a 
 forceps and cut with a scissors from this point around the apex to the oppo- 
 site side, thus removing a piece about one inch long and the size of the half 
 of a small lead pencil. Split this strip into two or three smaller ones for 
 class use. 
 
 To mount the heart strip tie silk threads to each end, one with a loop 
 one-half inch long and the other with a loop about four inches long. Place 
 the short loop on the hook of the glass-rod support provided for the purpose, 
 and the long loop over the recording lever. Use a straw lever of the power- 
 fulcrum-weight order mounted in a muscle lever holder. A total tension of 
 one gram is best for developing the contractions of the ventricular strip. 
 
 The holder mentioned above is made of a glass rod 4 to 5 mm. diameter 
 and 15 cm. long. Bend it at a right angle in the middle and then draw out 
 and turn a hook on one end, the hook being turned back on the rod. The 
 apparatus set up complete consists of a single iron stand with three clamps, 
 the top one to support the lever holder, the middle the glass rod, and the bot- 
 
THE PREPARATION OF THE VENTRICULAR MUSCLE. 
 
 67 
 
 Fig. 34. — The terrapin's heart, ventral view, showing how to cut an apex strip 
 for experimental purposes and how to split this apex into smaller pieces. 
 
 Fig. 35. — Apparatus as set up to demonstrate the contractions of the apex muscle 
 of terrapin's ventricle. The glass L-shaped holder should be set on the stand high 
 enough to allow of easy change of solution tubes. The figure shows the tube of physio- 
 logical saline and other details for the better illustration of the mounting of the heart strip 
 
68 
 
 EXPERIMENTAL PHARMACOLOGY. 
 
 torn one a platform on which rests the footed test-tube (1x3 inch specimen 
 tube) to contain the solution surrounding the strip. The ventricular strip 
 mounted in this apparatus with a tension of one gram and bathed in a solu- 
 tion of 0.7 percent sodium chloride will begin rhythmic contractions in from 
 10 to 40 minutes. These contractions will continue about two hours, 
 growing constantly smaller for the entire time. The strip may then be 
 revived by a bath of Ringer's solution or by serum, and may again be used 
 in the sodium chloride bath. 
 
 TO TEST THE ACTION OF DRUGS ON THE FROG'S OR 
 TERRAPIN'S HEART. 
 
 Two methods are used in this laboratory for the study of the action of 
 drugs on the frog's heart, both permitting of permanent records. The 
 
 Fig. 36. — Showing the method of recording the action of the frog's heart in place 
 n the body cavity. If the perfusion method is used the canula can be inserted with 
 greater ease if the frog is reversed on the support. 
 
 most convenient method is to pith the frog, open the thorax and expose 
 the heart, adjust the foot of a delicately poised heart lever on the venticle 
 and, while the record is being taken, irrigate the surface of the heart with the 
 
IRRIGATING AND PERFUSING FLASKS. 69 
 
 drug. Dissolve the drug in physiological saline and always take a previous 
 normal record under saline irrigation. This method requires the use of 
 relati\'ely strong solutions. The most convenient irrigating bottles are four- 
 or eight-ounce aspirator bottles with tubed foot for rubber connector. These 
 are each provided with a small-mouthed canula attached by a short rubber 
 connection, and the flow is regulated by a screw compress. Fit these 
 flasks with Marriotte stoppers and support them on a stand by a universal 
 buret clamp about the neck. 
 
 The second method, that of perfusion, is carried out best as described 
 by Walden in the American Journal of Physiology, Volume III, page 123. 
 Insert a canula into the inferior vena cava for an inflow and one in the aorta 
 for an outflow, or merely cut one aortic branch and let the outflow go free. 
 The canula is connected with two supply bottles, one for physiological saline, 
 the other for the drug in solution. The Marriotte stoppers should be set 
 at exactly the same pressure levels. Connect the two flasks with the inflow 
 canula by a T-tube brought as close as possible to the heart in order that 
 the solutions may be changed quickly with only a short connecting tube to be 
 washed out. Very weak solutions of drugs are required by this method of 
 perfusion. The frog's heart is quickly exhausted in pure saline solutions, 
 so, for certain prolonged experiments it is better to use the weaker Ringer's 
 solution for dissolving the drug. 
 
 Record the contractions of the ventricle by a thread from its apex to 
 the ventrical arm on a balanced horizontal lever. A flexible paper or 
 celluloid writing point will add to the accuracy and beauty of the records. 
 These writing points should be 2 to 3 cm. long by 0.5 cm. wide and made 
 of Hght-weight but hard note paper. 
 
 IRRIGATING AND PERFUSING FLASKS. 
 
 The quarter- and half-pint aspirator bottles manufactured by Whitall, 
 Tatum & Co., with tubed foot for attaching a rubber tube are particularly 
 adapted to both irrigation and perfusion of the heart. For use in irrigation 
 these bottles are clamped to a heavy based stand by a universal buret clamp 
 on the neck. Insert a tight-fitting rubber stopper with a 2 mm. glass tube, 
 to give a constant pressure level. A short heavy rubber connector provided 
 with a small screw compress and a glass dropper serves to regulate the speed 
 of the outflow. Such a flask attached to an independent stand and set at a 
 level so that the fluid drops only a few millimeters is an exceptionally satis- 
 factory method of applying solutions directly to the surface of the heart. 
 
70 EXPERIMENTAL PHARMACOLOGY. 
 
 Two perfusion bottles may be connected together by a T-tube for per- 
 fusion work. In this case the inflow canula is connected by a very short 
 (6 to lo cm.) tube of small caliber and is supported firmly by a clamp on 
 the T-tube. Or a Y-canula can be used and the flasks attached directly to 
 its limbs. In either case it is better to insert a small T-tube with light 
 spring clamp in order to wash out any drugs in the tubing. This canula, 
 when provided with an overflow, as shown by Gibson and Schultz in an 
 article now in manuscript, permits change from one solution to another 
 without a break in the pressure of the fluids. The connecting tubes for 
 the flasks should be 25 to 30 cm. long to permit adjusting. Set screw or 
 spring compresses near the bottle. Fill one flask with the normal solution, 
 the other with the drug. A very small amount of the fluid can be applied 
 by means of these perfusion flasks. 
 
 TO TEST THE ACTION OF DRUGS ON THE BLOOD-PRESSURE, 
 RESPIRATION, ETC., OF A MAMMAL. 
 
 1. The anesthetic. For anesthesia methods see page 65. 
 
 2. The operations. Blood-pressure is taken from one of two arteries, 
 the right common carotid, or the femoral artery. The femoral is practical 
 only for the dog. To expose the common carotid make a three-inch cut 
 over the trachea from the proximity of the larynx to the manubrium. Sepa- 
 rate the muscles down to the trachea, and then along the side of the trachea 
 till the common carotid artery and vagus come into view. Use the scalpel 
 handle and tear rather than cut the facias and muscles involved. Avoid 
 the veins and the laryngeal arteries. No blood need be lost after the skin is 
 cut. Separate the fascia binding the artery and vagus, using care not to injure 
 the latter. Place a bulldog forceps on the artery well toward the thorax. 
 Ligate the cephalic end. Lay and tie a ligature loosely about the intervening 
 stretch of artery for the canula. Grasp the artery at the cephalic ligature 
 and use the tip of the scissors to make a V-shaped cut two-thirds through 
 the artery wall and directed toward the heart. Insert the canula and ligate 
 it firmly with the ligature already laid. 
 
 The femoral artery is exposed by a 5 cm. cut over the artery where 
 the pulse can be felt near Poupart's ligament. The artery is prepared and 
 the canula inserted as described for the carotid. 
 
 The saphenous vein or the jugular are used for injecting drugs. 
 Insert a small washout canula toward the heart choosing the vein exposed 
 by the previous operation. Keep the vein closed with a bulldog forceps in 
 
ACTION OF DRUGS ON THE REFLEXES OF A FROG. 7 1 
 
 order to prevent small clots in the mouth of the canula, except when in- 
 jections are to be made. 
 
 Tracheotomy should generally be performed for all student work on 
 the mammals used in blood-pressure experiments in pharmacology. Free 
 the trachea immediately below the thyroid cartilage and insert a metal 
 canula made especially for the dog, or insert one limb of a glass T-tube of 
 as large size as the trachea will take. Tie it firmly with small stout twine. 
 
 The apparatus consists of a continuous paper kymograph (Ludwig's 
 weight-driven pattern arranged to run the paper in the right-handed direction 
 is the most satisfactory instrument) ; mercury manometer for measuring the 
 blood-pressure; respiration tambour (Marey's form); signal pen to record 
 stimulations, injections and other events; time signal; stimulating coil and 
 accessories complete; and a jacketed buret for transfusing warm solutions 
 into the vein. The recording pens of the manometer, tambour, signals, etc., 
 must all be adjusted to the kymograph in an exact vertical line. Fill the 
 lead tube of the manometer with lo percent magnesium sulphate from a 
 pressure bottle, take the zero level of the manometer, set the time signal to 
 write on this level, connect with the canula, and fill to a pressure of 130 mm. 
 mercury. Connect the respiration tambour directly with the side branch of 
 the tracheal tube. Start the kymograph, ink all the pens, remove the arterial 
 bulldog clamp, and the experiment is ready to begin. 
 
 A renal onkometric record should be taken with blood-pressure in the 
 investigations on certain drugs. Open the abdomen along the entire median 
 line, cut the wall transversely for two to three inches over the left kidney. 
 Strip the kidney of its fat and looser coverings and enclose it in a renal 
 onkometer. Adjust the overflow from the onkometer to the exact kidney 
 level and take a record of the variations with a small sized Brodie's bellows 
 recorder adjusted in line with the recorders mentioned abo\'e. 
 
 METHOD OF TESTING THE ACTION OF DRUGS ON THE . 
 REFLEXES OF A FROG. 
 
 Carefully destroy the brain and the medulla, but not the cord. Pre- 
 vent the loss of blood. Suspend the frog to a horizontal rod on a stand, 
 using a card hanger or a loop of string on the upper jaw. Stimulate the tip 
 of the toe with acid or with platinum electrodes and measure the reaction 
 time by counting seconds until the foot is withdrawn. The reaction time 
 may be recorded on a kymograph. Attach a horizontal writing point of 
 mucilaged paper to the leg above the foot. Take the speed of the drum with 
 
72 EXPERIMENTAL PHARMACOLOGY. 
 
 one magnet beating seconds, and record the instant of stimulation with a 
 second and independent magnet controlled by a contact key. 
 
 Take the normal reaction time first, then give the drug as an injection 
 in the dorsal lymph sac and allow about 20 minutes for absorption. Re- 
 measure the reaction time and repeat at intervals of 10 minutes to get the 
 progressive effects of the drug. 
 
 METHOD OF GIVING AND TESTING THE ACTION OF A DRUG 
 ON THE FROG'S GASTROCNEMIUS MUSCLE. 
 
 One should always compare the drugged muscle with a normal or un- 
 drugged muscle from the same frog. This may be done in one of two ways. 
 I St. With the circulation undisturbed. Pin the frog face down on a frog- 
 board, isolate and attach the tendon Achilles to a muscle lever, isolate and 
 stimulate the sciatic at its origin in the lumbar plexus using care not to dis- 
 turb the circulation, or stimulate the muscle directly. After a normal record 
 is secured then give the drug in the usual way and take a record of the other 
 or drugged muscle. 2d. Lay a ligature about one leg near the thigh tight 
 enough to stop its circulation. Give the drug by injection into the dorsal 
 lymph sac, or abdominal cavity, and after absorption is complete and the 
 tissues have been acted on by the drug (20 to 30 minutes) dissect out the 
 gastrocnemii and test. Always use the undrugged muscle first and the 
 drugged one immediately following. While the normal muscle work is being 
 • tested the drugged leg should have its circulation stopped by ligature. This 
 leaves the two muscles in more nearly the same state of nutrition and 
 asphyxiation. It is usually best to stimulate the muscle directly. There 
 are three tests that can be applied: i. Irritability, by the minimal stimu- 
 lus method; 2, Rapidity of the simple muscle contraction; 3, The amount 
 of work a muscle will do with simple contractions at constantly repeated 
 intervals. In this latter test stimulate once in two seconds, record on a 
 drum with speed of i mm. per second. 
 
 TRANSFUSION BURET FOR MAMMALS. 
 
 Transfusions of several cubic centimeters of liquid should be warmed 
 to body temperature. Inclose a 50 c.c. buret in an ordinary Liebig's con- 
 denser jacket and mount vertically on a heavy base stand. Mount and 
 connect a 6-inch funnel with the upper side tube of the condenser. Attach 
 a rubber tube fitted with a spring compress clamp on the lower side tube to 
 
ARRARATUS FOR THE STUDY OF THE ISOLATED MAMMALIAN HEART. 73 
 
 regulate the outflow of the warm water introduced by the funnel to keep the 
 perfusion liquid at the proper temperature. Mount a thermometer inside 
 the condenser with its bulb near the lower end of the apparatus. The buret 
 connections with the transfusion canula should be as short as possible and 
 their tubes should be provided with light screw-compresses. Where only 
 I or 2 c.c. of liquid is to be introduced it is unnecessary to warm it. In fact 
 a hypodermic syringe is most convenient where the volume of the injection 
 does not exceed 1.5 c.c. 
 
 APPARATUS FOR THE STUDY OF THE ISOLATED MAMMALIAN 
 
 HEART. 
 
 The mammalian heart isolated completely from the body can be 
 maintained in constant activity for several hours. It gives constant responses 
 to drugs in solution in the perfusion liquid best adapted to maintain its 
 life, i.e., Locke's solution with a small quantity of the animal's defibrinated 
 blood. Cats and rabbits are especially well adapted to this experiment. 
 The smaller size of the cat's or rabbit's heart makes it preferable to that of 
 a dog. 
 
 The points to be secured in the isolated heart apparatus are: i. A 
 uniform temperature of about 37° Centigrade. 2. An adjustable pressure 
 for the perfusion fluid. 3. A device for quickly shifting from the normal 
 perfusion to the drugged perfusion fluid without change in temperature, 
 pressure or any other factor than the presence of the drug. 4. An accurate 
 recording device. 
 
 The apparatus shown assembled in Fig. 37 accomplishes all of the 
 above points. The gas water heater connected as shown will maintain a 
 uniform temperature in the water jacket through which the perfusion tubes 
 run to the heart canula. The overflow from the water jacket is conducted 
 into a pan in which the perfusion fluid reservoirs receive preliminary warm- 
 ing. The heart is attached to a very short canula beneath the warming 
 jacket and the overflow of perfusion fluid maintains a temperature of the 
 heart only slightly below that of the warming jacket. 
 
 The pressure on the heart, i.e., on the perfusion fluid, is accomplished by 
 connecting the perfusion bottle with an air or oxygen reservoir, and this in 
 turn with a water reservoir which can be raised or lowered. The flow of 
 water from the pressure bottle into the closed system produces the desired 
 pressure on the perfusion system. At the same time the perfusion fluids 
 are aerated by the air (or oxygen) as it is forced into the reservoir, a result 
 
74 
 
 EXPERIMENTAL PHARMACOLOGY. 
 
 accomplished by conducting the perfusion bottle inlet tubes to the bottom 
 of the containers. 
 
 A uniform pressure is secured on both the normal and the drugged per- 
 fusion fluids by the system of tubes shown. If the clamp is removed from 
 
 K>= 
 
 Gulhne Cariiograph 
 
 Fig. 37. — Illustrating the assembly of apparatus for the pharmacological study of 
 the isolated heart of a mammal. The legends on the apparatus are self-explanatory. 
 
 the outflow tube of the drugged perfusion fluid at the exact moment a second 
 clamp is placed on the tube from the normal fluid reservoir (or vice versa) , 
 the shift will be accomphshed without change of pressure on the heart. The 
 tubes run independently to the canula which is itself so short that the time 
 
LIST or STOCK SOLUTIONS. 75 
 
 from the moment of turning a perfusion fluid on or off is reduced to a mini- 
 mum. The canula is provided with a side washout tube. 
 
 The Guthrie cardiograph shown is very adjustable in all essential fea- 
 tures. It gives satisfactory and accurate records, if care is used in inserting 
 the lever tips into the walls of the heart. This apparatus permits a direct 
 record on the ordinary kymograph. It also permits one to surround the 
 heart with a warm cup or jacket where greater constancy of temperature is 
 desired, as in research work. 
 
 LIST OF STOCK SOLUTIONS. 
 
 Make the solution up in 0.7 percent sodium chloride solution and in Ringer's 
 solution. Special solutions must be prepared for the mammalian heart experiments. 
 
 Aconite o.i percent. 
 
 Adrenalin hydrochloride o.ooi percent, o.oi percent, 0.05 percent, o.i percent. 
 
 Alcohol 95 percent, 2 percent, 5 percent, 10 percent, 20 percent. 
 
 Amyl nitrite 0.1 percent, pearls. 
 
 Atropine o.ooi percent, 0.002 percent, 0.1 percent, 0.2 percent, i percent, 2 per- 
 cent, 5 percent, and 1/120 grain tablets. 
 
 Barium chloride o.oi percent, 0.1 percent, 0.2 percent, i percent. 
 
 Caffeine 0.1 percent, 0.2 percent, 0.5 percent, e percent. 
 
 Calcium chloride 0.03 percent, 0.06 percent, i percent. 
 
 Carbolic acid 0.5 percent, i percent, 10 percent. 
 
 Chloral hydrate 0.1 percent, i percent, 2 percent. 
 
 Chloroform 0.05 percent, 0.1 percent, 0.5 percent, 20 percent in oil, pure. 
 
 Cocaine hydrochlorate o.oi percent, 0.2 percent, 0.5 percent, i percent, 2 percent. 
 
 Codeine 0.5 percent, i percent. 
 
 Curare 0.2 percent, i percent. 
 
 Digitalis 0.0005 percent, o.ooi percent, 0.002 percent, 0.1 percent, 0.2 percent, 
 0.5 percent, i percent. 
 
 Ether i percent, 2 percent, 4 percent, 6 percent, 8 percent, pure. 
 
 Ergot Squibb's fluid extract, 10 percent of fluid extract. 
 
 Hyoscyamine i percent. 
 
 Locke's solution. 
 
 Morphine acetate i percent, 2 percent, 10 percent. 
 
 Nicotine 0.02 percent, 0.1 percent, 0.2 percent, i percent. 
 
 Nitroglycerine 0.1 percent. 
 
 Physiological saline 0.7 percent. 
 
 Physostigmine 0.1 percent, i percent. 
 
 Pilocarpine nitrate 0.1 percent, i percent, 10 percent. 
 
 Potassium chloride 0.03 percent, i percent, 5 percent. 
 
 Potassium bromide 5 percent. 
 
 Quinine hydrochlorate 0.1 percent, i percent. 
 
 Ringer's solution, weak, strong. 
 
 Sodium nitrate o.oi percent, 0.02 percent. 
 
 Sodium sulphate i percent. 
 
 Strychnine nitrate i percent, 0.1 percent, .02 percent. 
 
 Thebaine 0.5 percent, i percent. 
 
 Veratrine 0.05 percent, 0.1 percent, i percent, i percent of fluid extract. 
 
76 EXPERIMENTAL PHARMACOLOGY. 
 
 REPORT FORM FOR EXPERIMENTS ON FROGS. 
 
 Animal Name 
 
 Weight Date 
 
 Experiment 
 
 I. Normal Reactions. 
 
 3. Respiration 4. Reflexes 5. Eye 
 
 I. Position, Activity, 
 etc. 
 
 2. Circulation, Heart, 
 Skin, Mucous Mem. 
 
 II. Action or the Drug. 
 
 Time Dose How given Dose per kilo. 
 
 Observations on: 
 h. m .s. ■ Apfjyijipg 2. Circulation 3. Respiration 4. Reflexes, etc. 5. Eye 
 
 III. Summary. 
 
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