29 MAY 1875, Page 14

AN2ESTHE'l'ICS AND THE LOWER ANIMALS. [TO THE EDITOR. OF THE

"SPECTATOR."] SIR,—It seems to be generally supposed in this country by people- who interest themselves in the present controversy about vivisec- tion, that chloroform and similar anwathetics can easily be, and generally are, administered to animals destined to undergo painful physiological experiments, with the effect of rendering these- animals totally insensible to any feeling of pain during the opera- tion. This supposition has likewise had the effect of making them suppose that vivisection may be carried out to any extent with advantage to humanity and no suffering to animals, pro- vided that chloroform be used ; and this feeling has become so pro- minent lately, both in the Press and in the two Bills before Parlia- ment, that it may not be considered out of place to point out the meagre ground which exists for any such supposition. The in- calculable advantages which mankind has derived from. chloro- form as a means of destroying the sense of pain have remained a dead-letter as regards the lower animals, in consequence of the very unsatisfactory state of our knowledge of the line which separates insensibility from death, especially in some of those- classes of animals that are most generally employed as the subjecta- of physiological experimentation. Many of these die apparently before they can become insensible through chloroform, some of them, indeed, as soon as it has been administered. The practical consequence of this uncertainty is that complete and conscientious ancestnesia, is seldom even attempted, the animal getting at most a slight whiff of chloroform, by way of satisfying the conscience of the operator, or of enabling him to make statements of a humane character. Not only, however, are those numerous cases to be regarded with due suspicion in which a slight whiff of chloroform is recommended to be given, but we have also to bear in mind that even where complete insensibility has been produced at the beginning of an operation, this effect only lasts for at most a minute or two, and during the rest of the operation, lasting perhaps for hours, the animal must bear its torture as it best may. Continued insensibility could only be maintained by continued careful administration by a special assistant, whose undivided attention would require to be concentrated upon this object This, I believe, is seldom, if ever done, and 1 am afraid that any compulsory provision of this kind would be regarded by most experimental physiologists as intolerable, if not impracticable.

At the same time, this leaves entirely out of sight that numerous class of operations in which anmstheties cannot be used, as they would interfere with the correctness of the results; and where, if used, they would render the experiment worse than useless.

Although probably 95 per cent, of medical men know little or nothing about the general practices in vivisection, yet they all are acquainted with the effects of chloroform on the human sub- ject, whose liability to the fatal effects of that agent scarcely bears. anycomparison with the extreme liability of the lower animals to such effects, and they can therefore corroborate what I have said regarding its administration.

In cases of operations on the human subject, a special assistant gives his whole attention to the administration of the ana3sthetie, so as to prevent either a wakening to sensibility, on the one hand, or"' a sleeping-away into death on the other. Yet, in spite of the exer- cise of the greatest care, fatal results often occur, so often, indeed, that some medical men make a speciality of the administration of ansthetics, and undertake no other practice.

I have only mentioned the foregoing in order to show the un- satisfactory state of our knowledge regarding the administration of anesthetics to Ulan and, by comparison, to his fifty-times more susceptible fellow-creatures.

In consequence of this condition of things, many expedients have been devised with the view of obtaining some of the ad- vantages of anesthetics, without risking the loss of the animal before the experiment has been completed.

One of the best that I have seen is to have an apparatus like a nosebag, or elongated muzzle with leathern walls, in the bottom -of which a piece of sponge or wool, impregnated with chloroform, is placed. This, however, I have only seen used on dogs, and as the quantity of chloroform used is very small, in order to avoid fatal results, it has the effect of leaving the animal more or leas con- scious during the course of the operation. Others use a hypo- dermic injection of opium or chloral, the effect of which is similar to the same in the human subject.

The almost fiendish employment of Urtui, which I have elsewhere exposed, has its utility in the fact that the animal is kept as quiet -as it would be under chloroform, although its action is the oppo- site of anesthetic, and it has no place under that head. The very fact that we sometimes see physiologists recommend chloroform to be given -with urari, shows either that they do not know that the action of the formervenders the latter in most cases unnecessary, -or, what is more probable, that they wish to throw dust in the eyes of those who seek evidence of cruelty in the pages they have published.

Personally, I may add, that the first experiments which I attempted-bo make as a student in my own private room failed, because in my anxiety to produce anesthesia I found that the animal had died before the experiment could be commenced ; this, too, at a time when I had much experience in administering chloro- form in the operating-theatre of the hospital. I, therefore, gave up the idea of trying such experiments, until I had had an opportu- nity of seeing how experienced vivisectors managed it. I have since then had ample opportunities of seeing, and the result of my experience was embodied in a remark I made in a letter published three months ago, that "I am inclined to look upon anesthetics as the greatest curse to vivisectable animals."—I