From the time at which I first saw Ether-Inhalation successfully practised in January last, I have had the conviction impressed upon my mind, that we would ultimately find that other therapeutic agents were capable of being introduced with equal rapidity and success into the system, through the same extensive and powerful channel of pulmonary absorption. In some observations, which I wrote and published in February last, relative to the inhalation of sulphuric ether in midwifery, I stated that, in several obstetric cases, I had used ergot of rye in this way, along with ether. – (See Monthly Journal of Medical Science, pp. 724; and 795, case of successful inhalation of opium, to arrest the vomiting of pregnancy.)
With various professional friends, more conversant with chemistry than I am, I have, since that time, taken opportunities to talking over the idea which I entertained of the probable existence of discovery of new therapeutic agents, capable of being introduced into the system by respiration, and the possibility of producing for inhalation vaporizable or volatile preparations of some of our more active and old established medicines: and I have had, during the summer and autumn, ethereal tinctures, &c., of several potent drugs, manufactured for me, for experiment, by Messrs Duncan, Flockhart, & Co., the excellent chemists and druggists of this city.
Latterly, in order to avoid, if possible, some of the inconveniences and objections pertaining to sulphuric ether, – (particularly its disagreeable and very persistent smell, its occasional tendency to irritation of the bronchi during its first inspirations, and the large quantity of it occasionally required to be used, more especially in protracted cases of labour,) – I have tried upon myself and other the inhalation of different other volatile fluids, with the hope that some one of them might be found to possess the advantages of ether, without its disadvantages. For this purpose, I selected for experiment and have inhaled several chemical liquids of a more fragrant or agreeable odour, such as the chloride of hydro-carbon (or Dutch liquid), acetone, nitrate of oxide of ethyl (nitric ether), benzin, the vapour of iodoform, &c.* I have found, however, one infinitely more efficacious than any of the others, viz., Chloroform, or the Perchloride of Formyle, and I am enabled to speak most confidently of its superior anaesthetic properties, having now tried it upon upwards of thirty individuals. The liquid I have used has been manufactured for me by Mr. Hunter, in the laboratory of Messrs Duncan, Flockhart, & Co.
Chloroform was first discovered and described at nearly the same time by Soubeiran (1831), and Liebig, (1832); its composition was first accurately ascertained by the distinguished French chemist, Dumas, in 1835. – See the Annales de Chimie et de Physique, vols. xlviii, xlix, and lviii. It has been used by some practitioners internally; Guillot prescribed it as an anti-spasmodic in asthma, exhibiting it in small doses, and diluted 100 times. – (See Bouchardat’s Annuaire de Therpeutique for 1844, p. 35). But no person, so far as I am aware, has used it by inhalation, or discovered its remarkable anaesthetic properties till the date of my own experiments.
It is a dense, limpid, colourless liquid readily evaporating, and possessing an agreeable, fragrant, fruit-like odour, and a saccharine pleasant taste.