J|25 ON THE COMPOSITION OF ALCOHOL. 



able quantity of alcohol, which in Lavoisier's process was 

 confounded with the liquid that had disappeared from com- 

 bustion. 



Process dc- ]y[y lamp, on the wick of which was a particle of phos- 



scribcd. ,- .,-, , , . 



phorus, was placed with a thermometer under a receiver 



standing in water*, and half filled with common air. To 

 this I added oxigen gas, and the mixture occupied the space 

 of 651 cubic inches, the barometer standing at 27 inches, 

 and Reaumur's thermometer at 17° [70|° F]. Before the 

 • combustion, according to analysis by Volta's eudiometer, it 

 contained 228'25 inches of oxigen gas, and 422'75 of nitro- 

 gen. 

 Gasses from The lamp, kindled by a burning glass, consumed 35f grs. 



thecombus. ^f alcohol. An hour after it was extino'uished, the thermo- 

 tionof35-3grs. , , . , . ^ ,, « r x«-i , 



of alcohol. meter under tlie receiver having tallen to 17° [70 J°], the air 

 contained in it was reduced to 599 cubic inches; and being 

 analysed by limewater and Volta's eudiometer it was found 

 to consist of 



Carbonic acid gas 77'87 



Oxigen gas • • 98*42 



Nitrogen gas 422*71 



599. 



The carbonic 1 must remark, that the quantity of carbonic acid gas, 

 acid gas tn too vvhich formed only 0*13 of the residuum, was too small to 

 ties to be ab- ^^ perceptibly absorbed by the water under the receiver at 

 sorbed. the high temperature at which the process was conducted, 



and in the short space of time between the combustion and 

 the examination by the eudiometer. I satisfied myself of 

 Water prefer- the truth of this by direct experiment. Besides I found an 

 able to mer- advantage in substituting water for mercury under the re- 

 absorbs the lit- ceiver, as a small quantity of alcohol is always volatilised 

 tie alcohol eva- without being burned, even while the combustion is going 

 on. If the receiver be lifted up immediately after the com- 

 bustion, and while full of vapour, we find this diffuses an 

 alcoholic smell. This vapour, which does not burn because 

 it is in great part aqueous, soon condenses in the water of 

 the trough ; but if it stood over mercury, it would increase 



• In Lavoisier's experiment the receiver stood over mercury. 



the 



