120 M. It. Bunsen on the Law of Absorption of Gases. 



Hence when 



^VP = A, r 1 VP = A 1 , (l + ^)=B, and (l+^)=B 1 , 



we obtain 



AB, x 



(AB, + A,B) x+y 

 AjB _ y 



(12) 



(13) 



(ABi + AiB) x + y l 



It is clear that, vice versa, the composition of an unknown 

 gaseous mixture may be found from the change of volume ensuing 

 from absorption by a liquid. In this way it is possible to analyse 

 mixtures of gases by a purely physical experiment unassisted by 

 chemical decomposition. Such absorptiometry determinations, 

 as I term them, are, under certain conditions, scarcely less cor- 

 rect than a chemical analysis, often much more simple and con- 

 venient. Often, indeed, this mode of analysis is of immense 

 importance, as solving questions which by other methods are 

 not determinable. 



Let us next consider tbe case in which two gases are given 

 whose relation to each other is to be determined by an absorp- 

 tiometric experiment. 



Let x be the original volume of the first gas reduced to the 

 pressure 1; 



Let x 1 be the volume of the same gas unabsorbed, also reduced 

 to the pressure 1 ; 



Let v' be the volume of unabsorbed gaseous mixture at the 

 pressure P'; 



x 

 The pressure on the unabsorbed gas 1 is then -j. If the ab- 

 sorbed amount of the gas 1 be reduced to this pressure, the 

 volume is ah; reduced to the pressure 1, it is therefore 



7 ah ' 



and hence 



, x' , ,/, ah\ 



ah 



1 + — 



tr 



Hence the pressure of the unabsorbed gas 1 is 



x 

 v' + ct h ' 



