184 M. R. Buusen on the Law of Absorption of Gases. 



coefficient of oxygen for decreasing temperatures is therefore 

 parallel to the corresponding curve for nitrogen. 



If we take the following as the true composition of atmo- 

 spheric air, — 



Oxygen .... 02096 = 

 Nitrogen .... O7904=N 



1-0000 



and substitute the values of V,, V, 0, and N in the former equa- 

 tion, we obtain the value of the absorption-coefficient of oxygen 

 « = 2-0225/3, when /3 is the absorption-coefficient of nitrogen. 



10. Atmospheric Air in Water. 



We have seen in the former part of the paper that the relative 

 proportion in which the constituents of a mixture of gases are 

 absorbed by water does not alone depend upon their several 

 absorption-coefficients, but also upon the relative proportions in 

 which they are mixed. If the absorption-coefficients are different, 

 the gases dissolved in the water are not in the same relation as 

 those in the free gas. This last undergoes therefore a change 

 in its composition, which varies with the relation of the mass of 

 the water to that of the gas. For this reason the absorption- 

 coefficient of a mixed gas can only be calculated from the relative 

 proportions of the constituents and their several absorption-co- 

 efficients, when the volume of the gas is so great in comparison 

 with the mass of the absorbing liquid, that the alteration effected 

 by the absorption in the composition of the residual gas is inap- 

 preciable. The true absorption-coefficient of air is therefore 

 found only in those phenomena of absorption in which these 

 conditions are fully carried out. 



If we take, as above, for the mean atmospheric composition, — 



Oxygen .... 0-2096 = 



jen 

 Nitrogen 



0-7904 = N 



1-0000 



by substituting the value 1 for N-fO, and for V and for P the 

 value 076, and lastly, for N and the above values, we obtain 



