ON THE COMPOSITIOV OP ALCOHOL. g5^ 



floes not imply, that the nature of the problem necessarily 

 requires it : it arises from the particular artifice which is em- 

 ployed in finding the value of v, the ordinate of the circle; 

 and is a matter of mere commodiousness, suggesting no 

 other reason for their appearance, than that of a necessary 

 consequence of such a particular step. 



Royal Military Academy, Woolwich^ 

 Oct. 13th, 1808, 



IV. 



Essay on the Composition of Alcohol and of Sulphuric Ether, 

 By Theodore de Saussure. 



^Continued from p. 231. 



Sect. III. Analysis of alcohol by detonating its vapour toitk 

 oxigen gas, 



JLn the preceding analysis I remarked, that alcohol, burn* .j'f,g^j^^,jg^^£. 



ing in a lamp under a closed receiver, diffuses a vapour, that thealcohol not 



has an alcoholic smell ; it is very probable therefore, that ^"'^"^. '" *^* 



. preceding ex- 



the whole of the combustible disappearing from the lamp periments. 



does not burn. Accordingly I sought a process, that should its vapour de* 

 effect a complete combustion of the alcohol; and this I tonated. 

 found in detonating a mixture of vapour of alcohol and 

 oxigen gas over mercury, by the electric spark, in Volta's 

 eudiometer. 



This process applied to the analysis of alcohol is some- j^^-^^ ^ jjfjj, 

 what corapltx. It requires a knowledge of the weight of cult process. 

 the vapour of alcohol at a given temperature and pressure, 

 and the determination of the increase of volume of the oxi- 

 gen gas by the presence of the vapour. The experiment ^ 

 must be conducted at a temperature exceeding 15° R. [O'G" 

 F.] to obtain sufficiently decisive results; and neither the 

 thermometer nor the barometer must vary during the course 

 of it, which requires practice and quickness in several of its 

 maoipulations. 



S 2 J washed 



