Source:  Snow, John. BMJ 2 (August 1, 1857): 654. [ltr. to ed., 25 July 1857]

Mr. A. Prichard on amylene

Letter from John Snow, M.D.

Sir,--There are some paragraphs respecting amylene in the address of the President of the Bath and Bristol Branch of the Association, published in the Journal of to-day, which seem to call for some remarks from me; and I shall therefore be obliged if you will allow me a little space for them.

Mr. Prichard appears to me to be entirely misinformed with respect to every statement which he makes regarding amylene. He commences by saying, "Some months ago we were startled by the announcement that a new anæsthetic had been discovered, equal to chloroform in every respect, and superior to it in this one most important particular, that it was devoid of the amount of danger to life which all reasonable persons admitted to be connected with the use of chloroform." I did not make the announcement of the use of amylene in a way to startle any one, but, on the contrary, tried to explain why a greater number of volatile narcotics had not been already been introduced, and expressed an expectation that others would be discovered. What is of more importance, it was not announced that amylene was equal to chloroform in every respect, or that it was superior to it in this one most important particular, etc. I gave an account of certain advantages which amylene has over chloroform, and of one or two disadvantages which it has in comparison with that agent; but I did not place its probable freedom from danger either in one scale or the other. I spoke separately of the probable freedom of amylene from danger, and I said no more in its favour than I had frequently said of chloroform. My words were as follows: "While I cannot venture to predict for it the absolute safety which seems to attend sulphuric ether under all circumstances, I confidently trust that it will be perfectly safe with careful management." (Medical Time and Gazette, January 1857, p. 84.) Although these hopes have not been literally fulfilled, I believe that in course of time, they will prove not to be without reasonable foundation. There are some circumstances connected with the accident which has occurred, which indicate how a similar result may be most probably avoided.

Mr. Prichard is in error is saying that amylene proved fatal much sooner than chloroform had. He is not speaking of the relative extent to which the two agents were probably used, either in this country or elsewhere; for sooner is an adverb of time. Now, chloroform was first used in its undiluted state by Dr. Simpson, in the early part of November 1847; and the first death from it occurred near Newcastle, on January 28th, 1848, or between two and three months afterwards; and it was soon followed by others. Amylene was first employed on November 10th, 1856; and the accident which happened from it occurred on April 7th, nearly five months afterwards. I have not heard of any other casualty from its use, although I believe that it is still used largely in many hospitals in France. I have administered it in 94 cases, many of them capital operations, since the accident above alluded to, making in all 238 cases. I compare its effects with those of chloroform, which I exhibit to a much greater extent; and I see no reason to alter the opinions which I gave in a paper, an abstract of which appeared in the Journal of January 17th. I may remark, in correction of one statement of Mr. Prichard, respecting practical experience, that I did not publish any opinion respecting amylene till I had administered it in some capital operations, as well as several minor ones.

Mr. Prichard is so entirely mistaken on every point respecting amylene, that I cannot feel personally concerned with the tone of his remarks; but, supposing he had been correct regarding the circumstances, and that amylene had been introduced in a sanguine manner, and with great praise, and that it had been already abandoned, I doubt whether the style of sarcastic reprimand, if not exultation, which he has employed, would be calculated to encourage other laborious attempts to advance the science and practice of medicine.

I am, etc.,

John Snow

Sackville Street, July 25th, 1857.