M. R. Bunsen on the Law of Absorption of Gases. 117 



in h volumes of liquid under the pressure P is given by the 

 equation 



V=W76 (2) 



If two or more gases are mixed together, the absorption of the 

 constituent parts is proportional to the pressures to which these 

 parts are severally subjected. Let the volumes v v v%, v„, fig. 4, of 

 different gases, each under the pressure P, remain unmixed one 

 above the other, separated by the diaphragms i i, i i f, ; each of the 

 gases exerts a pressure P against the inclosing diaphragm ; with- 

 draw the diaphragm and remove the resistance opposing the action 

 of the pressure, and the particles of v x will, in virtue of the pressure 

 P, penetrate into the gases r 2 v n , which offer no resistance. The 

 motion of the particles of the gas v x ends with a state of equi- 

 librium, which ensues when the pressure exerted by v x has 

 become equally great at every point of the space v 1 -rv 2 + v n ; 

 that is, when the gas v } exerts a uniform tension throughout the 

 total volume. The pressure on v^ is therefore, according to the 

 law of Mariotte, 



v y + v 2 + v n 



In like manner it is found that the gases v 2) v n , when equili- 

 brium has ensued, are subject to a pressure of 



Pand 



V \ + V 2 + V n V i + V 2 + V„ 



From these pressures of the constituent parts the total pressure 

 of the mixture is found to be 



p_ v \ p ■ y 2 p ■ v n p > 



Vy+V^ + Vn V t +V 9 + V tt Vi+V^ + Vn 



The amount of each constituent gas absorbed is proportional 



to the pressure on that constituent part P: and these 



1 F Vi -f » 2 + v n 



pressures may be distinguished as " partial pressures," in con- 

 tradistinction to the "total pressures" on the whole mixture. 



If a mixture of gas, unalterable by absorption, consists of two 

 or more volumes of chemically different gases v v v 2 , v n) the 

 amount of each gas dissolved in h volumes of liquid under the 

 pressure P, when a,, « 2 , a„ are the respective absorption-coeffi- 

 cients of the different gases at the observed temperature, is of 

 the first gas, 



a ] hYv i 



0-76(w, + t> 9 -|-»,,)' 



(3) 



