EFFECTS OF CHLORIDE OF HYDROCARBON. 
247 
sing oil gas, and was designated by him hicarburet of hydro- 
gen. Miischerlich afterwards obtained it by distilling, at 
a high temperature, benzoic acid with an excess of slaked 
lime. 
It is a clear colourless liquid, of a peculiar ethereal odour, 
with a specific gravity of 85, and boils at 1S6°. it is 
believed to be composed of two proportions of carbon and 
one of hydrogen. Its formula is H; or perhaps, more 
properly, C'^ It is polymeric with the hypothetic 
radical formyle. 
lu my experiments with benzin, I found it capable of 
producing ansesihesia ; but the ringing and noises in the 
head accompanying and following its inhalation were so 
excessive, and almost iniolerable in the case of myself and 
others, as to seem to us to render its practical applications 
impossible, even had there been no other objections to its 
use. Latterly, Dr. Stow has tried its employment upon 
some patients for tooth drawing, and in one instance of 
amputation. In this last case it produced convulsive 
tremors. — Lancet for 12ih February, 1S4S, p. ISO.) 
Aldehyde. — Aldehyde or hydrate of oxide of acetyle, was 
first noticed by Doehereiner, in distilhng together sulphuric 
acid, alcohol, and peroxide of manganese, but it was left for 
Liet)ig to fix and determine every thing about its chemical 
nature. It is a colourless limpid liquid, of specific gravity 
0.7.91. It is very volatile, boiling at 72°. It spontaneously 
changes when Ion? kept, and is converted into two sub- 
stances, a solid and a fluid, metaldehyde and elaldehyde. 
Liebig found it to be composed of tour atoms of carbon, 
four atoms of hydrogen, and two of oxygen, and its formula 
isC^H^O-faq. 
Professor Poggiale, of Pari^, has lately made some expe- 
rinients with dogs on the inlialation of the vapour of alde- 
hyde, and from these has concluded that its anaesthetic 
effects will be found more prompt and energetic than those 
of sulphuric ether or cliloroform. It certainly possesses, 
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