Lecture on chloroform, and other narcotic vapours, delivered at the Royal Medico-Botanical Society, March 16, 1848 / [John Snow].

  • Snow, John, 1813-1858
Date:
[1848]
Catalogue details

Licence: Public Domain Mark

Credit: Lecture on chloroform, and other narcotic vapours, delivered at the Royal Medico-Botanical Society, March 16, 1848 / [John Snow]. Source: Wellcome Collection.

    1/2
    ‘Dr. Snow considered the introduction of the use of ether vapour for the pre- vention of pain second only to the discovery of vaccination, in the direct benefit it con- ferred on mankind, and second only to the discovery of the circulation of the blood, in the advantages it would confer on medical science. Chloroform was in some respects an improvement over ether, which, however, was the great discovery. He then described the physiological effects of chloroform, dividing them into five de- grees, and said that the description he gave was applicable to ether, and to some other vapours. The pulse was more or lese acce- lerated during inhalation of either chloroform or ether, and was not diminished in power when the effects of the vapour were not carried too far, unless sickness was induced, which was apt to occurif the inhalation took place soon after a meal, and deep insensi- bility was induced. It was not easy to lay down any rules with respect to the state of the pupil, but the sensibility of the edge of “the eyelid affords a very good sign: when this was abolished, the knife might be used without causing a flinch; but it is not always necessary to wait for this symptom. He mentioned some cases in which ether and chloroform had enabled the surgeon to reduce old dislocations, and_ strangulated hernia by the taxis, when otherwise an ope- ration must have been performed. There was, on an average, less mental ex- -citement a chloroform than from ether ; but the rigidity and struggling which occa- sionally occurred in the third degree was certainly as frequent from the former as = from the latter agent, if not more so. Chloroform was eight or ten times more powerful in its effects than the same quan- tity of ether; and he was now in a position to explain the reason of this. He had exa- mined a great number of volatile liquids, and he found that the power of them all was in an inverse ratio to their solubility in water, and consequently in the blood; that is to say, that the more soluble they were, produce a given effect. The table suspended in the room exhibited a number of these liquids, in the order of their solubility, and the power of a given quantity of each is in the same order :— Alcohol . .. . eu in all Pyroxilic Spirit proportions. Acetone e Acetate of Guide of Me- thyle . Acetate Ethyle ©. Oxide “of Ethyle, (Sul- phuric Ether) . } oe Nitrate of Oxide a sess 6 50 of Oxide ose thyle 3. < : Todide of Ethyle Siac Chloroform a eerGes) 44 Bromoform . About the same. Bichloride of Carbon 0°4 100 Bisulphuret of Carbon 0°13 50 Benzin ee Oe oe very spar- Metacetone ingly soluble. The first column shewed the quantity of liquid, by measure, that 100 pamte of water