198 



NATURE 



\yune 29, 1876 



only, but the dread of the pain enforces on the ope- 

 rator the necessity of administering the ana^sthetic. A 

 few inhalations of the narcotic vapour are made, and in 

 an instant the body, a moment or two ago animated and 

 full of life and energy, is lifeless in the hands of the 

 administrator of the narcotic. 



There is no more painful agony to a practitioner of me- 

 dicine than a catastrophe of this character. He feels as 

 if the whole beneficent art of anaesthesia were, after all, 

 a mockery ; as if it were better that tens of thousands 

 should suffer pain than that one should die under his 

 directing hand merely to save a brief period of pain. 



From the first of the reintroduction of anaesthetics 

 these unhappy fatal failures from them have occurred to 

 darken with the shadow of death the retreat of pain from 

 the earth. What more natural, what more humane a 

 labour than that which is devoted to the discovery of a 

 means by which this shadow of death may also be made 

 to fade from the picture ? To me this labour has been a 

 life's work. I have pursued it in two directions. 



{a) By endeavouring to discover anaesthetic methods 

 which shall carry with them no danger to life. 



ip) By endeavouring to discover means that shall 

 restore safety when danger is incurred from the use of the 

 present imperfect anaesthetics. 



In conducting both these lines of research it has been 

 necessary to experiment on the inferior animals. There 

 is no other method. If the most promising new chemical 

 agent for anaesthesia were put into my hands to-day by 

 the scientific chemist, I could not administer the agent 

 direct to the human subject on mere speculation. It is 

 true I have, from long experience, been able so to under- 

 stand the characters of anaesthetics that I can formulate 

 them theoretically. If the chemist gives to me a sub- 

 stance and tells me its atomic composition, its physical 

 properties of solubility, of weight, vapour density, and 

 boiling point, I know at once whether it is or is not an 

 arK5thetic, and I can reject on the spot some substances 

 from and by reason of this knowledge, all of which, by 

 the way, has been acquired by experimental research. 

 But if the chemist gives to me the very thing I want it is 

 still impossible to proceed to apply it to practice on man 

 before testing its action on animals inferior to man, for I 

 have found that some of the very simplest and seemingly 

 most innocuous of substances are most fatal. 



Qne of the pioneers of anaesthesia with whom I had 

 the privilege to live and work, did once introduce into 

 practice a new, effective, and, in atomic construction, 

 very simple anaesthetic, In the course of a compara- 

 tively few administrations of this agent to man, two 

 deaths resulted. To the end of the useful life of this, my 

 friend, he never ceased to regret that he had not first 

 subjected the agent to more vigorous tests of action on 

 animals inferior to man. Once in my researches I got 

 under observation another ansesthetic which seemed per- 

 fect. I should have introduced it into practice, had not 

 the lesson I had learned above corrected the error. For 

 on submitting the new agent to the required strain of 

 experiment, I found it so fatal to animals that had I put 

 it forward I should certainly have deepened the shadow 

 of death on the picture of retreat of pain. Twice in the 

 same manner I have prevented other men from intro- 

 ducing anaesthetics which did not bear the full test of 

 proof of experiment on the inferior animal. The reason- 

 able mind will take in all these practical points, and, I 

 think, will come to the conclusion that for no application 

 to the necessities of man and of all other animals could 

 the lives of inferior animals be more justly applied. To 

 kill animals for food, to apply them to works of useful 

 labour, is not more just. 



Method of Experimentation. 

 The method of experimentation I have pursued has 

 taken two courses : — 

 , {a) The subjection of animals to narcotising gases or 



vapours for the purpose of inducing in them anaesthetic 

 sleep, observing the action of the narcotic through all 

 its degrees of action, and the mode in which it destroys life 

 when it is pushed to the point of destruction of life. 



{b) The subjection of animals to local methods of 

 abolishing pain, or, more correctly, of destroying pain in 

 parts of the body locally, so that operations may be per- 

 formed painlessly while the general consciousness re- 

 mains, and without any danger at all to life. 



In carrying out the first of these inquiries, the plan 

 pursued was as follows : — A narcotising chamberl was 

 used, the precise capacity of which was determined. 

 The chamber, made of glass and iron, was, when closed, 

 air-tight, but it was furnished with openings through 

 which it could be charged with the precise measures of the 

 narcotic vapour or gas required. It was also so arranged 

 that the temperature and dryness, and when necessary, 

 pressure of the atmosphere within it could be moderated. 

 Briefly, the chamber was so constructed that the action 

 of every volatile narcotic substance could be tested in it 

 under all known external conditions. 



The animals subjected to experiment have as a rule 

 been of two kinds — rabbits and pigeons. Rabbits have 

 been used because when they are allowed to sleep to 

 death in the vapour, or when they accidentally sleep to 

 death, they are good subjects for examination after death, 

 and tell clearly the reason of death. Pigeons have been 

 used for two reasons : first because they succumb more 

 easily to anaesthetics than any other animals, easier even 

 than man ; secondly because during sleep they give 

 indications of dangerous or troublesome effects, such 

 as rigidity and vomiting, quite as easily as man. If, 

 therefore, a pigeon will go safely and easily through an 

 anaesthetic sleep, the inference is fair that a man will do 

 so ; and in all cases where I have found the anaesthesia 

 so safe and satisfactory on these animals — rabbits and 

 pigeons — as to commend the anaesthetic which produced 

 it, I have always proceeded to try the effect on the human 

 subject by inhaling the anaesthetic myself until it produced 

 the insensible sleep. 



In experimenting on the animals, they have been gently 

 introduced into the narcotic chamber from above, and as 

 they have passed into insensibility, each of the stages of 

 narcotism — usually four in number — have been carefully 

 recorded by their phenomena. The facts have been tabu- 

 lated in set form so as to show, per-centage of vapour 

 diffused, time required to produce insensibiliiy, period of 

 each stage, muscular disturbance, state of the respiration, 

 state of the heart pulse, change of animal temperature, 

 and condition of the pupil. In cases of recovery from the 

 anaesthetic, the signs and period of recovery have been 

 recorded ; in cases of death in the anaesthetic sleep, the 

 time and mode of death whether by the heart or by the 

 respiration, have been recorded. 



I should remark that these researches have not been 

 made at any regular times. They have been suggested 

 by the study of some chemical substance which presented 

 some promising qualities for the object in view. I believe 

 no new substance of this kind has for the last twenty-five 

 years escaped my observation. 



On the animals themselves no pain can be said to have 

 been inflicted. The worst that has happened to them has 

 been that they have passed into deep sleep and have 

 waked again just as a human being who has taken 

 chloroform successfully for an operation, sleeps and 

 wakes. Or else they have passed into sleep and from 

 sleep into death, a mode of dissolution so serene, so 

 painless, as to be an enviable imitation of natural 

 euthanasia. 



In the researches on local means of relieving pain, the 

 part to be anaesthetised has been simply subjected to the 

 action of the anaesthetic. At first I used lower animals 

 for this method of inquiry, but owing to their comparative 

 low sensibility they proved unsatisfactory. A mode of 

 local anaesthesia which on a dog or rabbit seems abso- 



