ON THE COMPOSITION OF ALCOHOL. 225 



mas still a little aqueous, and was farther rectified by dis- ' 



tilling from an equal weight of muriate of lime, and again 

 drawing off only half. 



As we cannot expect to attain the truth in a business of x^ree proces- 

 so much difficulty as that I had undertaken, but by coming ses employed 

 at the same result in different ways, I employed three dif- eacirorher*'^ 

 ferent processes for decomposmg the alcohol. 



In the first I burned the alchohol by means of a lamp Fir^t. 

 under a receiver filled with a mixture of oxigen gas and 

 common air, as Lavoisier did*, and I examiiied the products 

 of this combustion. The results obtained by this analysis 

 were the least accurate. 



In the second I effected the decomposition of the alcohol Second. 

 by the instantaneous detonation of the elastic or gaseous va- 

 pour of this liquor with oxigen gaa in a Volta's eudiometer. 



The third analysis was made by decomposing the alcohol Third. 

 i>a a redhot tube of porcelain. 



Sect. II. Analysis of alcohol by slow combustion in a close 

 vessel* 



The lamp I employed for burning the alcohol was a gra- Alcohol burn- 

 duated glass tube closed at its lower extremity. It was 6 ^^ slowly in a 

 iaches high, and 3 lines in diameter internally. The wick *^ °*^ ^*^^*^ * 

 was a slender cylinder of amianthus, passing through a me- 

 tal cap, which kept it in the axis of the tube. I had as- 

 certained by previous observation the weight of alcohol cor- 

 responding with each division of the tube, so that I could 

 tell by simple inspection of the column of fluid in the 

 lamp, without taking it out of the receiver to weigh it, the 

 weight of alcohol consumed at the instant of its extinction. 



I preferred this method to that of Lavoisier, who weighed This method 

 his lamp before and after the experiment. In this way the Preferable to 

 lamp could not be taken out of the receiver to weigh it, and 

 to analyse the air in the receiver, till the latter was cold; 

 for it was of essential consequence to note the diminution 

 of the volume of air by the combustion. This cooling re- 

 quires near an hour ; and during this period the high tem- 

 perature prevailing under the receiver volatilizes a coDsider- 



• Journal de Phisique, vol. XXXI, p. 55, 



Vol. XXI.— Nov. 1808. Q able 



