LMG 48 (1851): 370.

My Dear Mr. Smith, - I beg to say in answer to your inquires, that I am not aware the 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.