Source: Snow, John. London Med. Gazette 48 (1851): 370. [ltr., 29 August 1851]

My dear Mr. Smith

This note from Snow, undated, was imbedded in a letter to the editor written by Henry Smith, FRCS.

[The relevant portion of Mr. Smith's letter to the Editor are as follows:]

It has fallen to my lot to witness the effects of chloroform in operations in these localities [upper and lower jaw], and the dangers when the agent has been skillfully employed, has appeared to me to be only assumed, and not real. I was anxious that it should be tried in the present case, and therefore was glad to avail myself of the experience of Sr. Snow; this gentleman considered that there would be no danger in using chloroform, and having the most perfect confidence in his judgment, I gladly acceded to his wish; and was much pleased with the beneficial manner in which it acted, during a somewhat protracted operation. I believe that this is the first instance, (at least made public), in which the operation of tracheotomy has been performed under the influence of chloroform. I made inquiry of Dr. Snow, who has had a vast experience in its use, and also requested him to state his reasons for not fearing its employment in such a case. In answer, he sent me the following note, which he has kindly permitted me to append:--

My Dear Mr. Smith,--I beg to say in answer to your inquires, that I am not aware that chloroform or any similar agent has been given in the operation of tracheotomy, except in the case of your little patient. I believe that many medical men would have objected to the employment of chloroform during tracheotomy, or a case in which extreme difficulty of breathing existed, but the following are the reasons which induced me to recommend it, when you asked my opinion on the subject:--1st. Chloroform in moderate quantities does not diminish the strength of the respiratory movements. 2nd. I have ascertained by experiments on animals that a larger quantity of air is not required to support life under the influence of chloroform and other narcotics than in ordinary circumstances; but, on the contrary, that they can actually subsist on less air than in the normal state. And 3rd, the struggles of the child that would be occasioned by pain and fright, if the operation were performed in the conscious state, would cause an increased demand for breath, and be a real source of danger.

The vapour was given very slowly at first, in order not to embarrass the child by its pungency, and the result of its administration fully realized our expectations. The patient was quiet and passive, and the difficulty of breathing and blueness of the lips were certainly not increased by the chloroform.

I remain,

Yours very truly,

John Snow

54, Frith Street, Soho.

I will add nothing more to the clear and forcible remarks here made, but will only take this opportunity of acknowledging my gratitude to Dr. Snow for the great assistance which he has rendered to me, not only in this instance, but in several other serious operations.

[Henry Smith, FRCS]