>94 



Mr. L. Vegard : Contributions to 



I£ /i(c, p, T) and / 2 (c, p, T) are introduced, we get the 

 following very important combination : 



d/i(c ,ff> T) + c d/ 3 (c, />, T) _ Q ^ . . (5) 

 dc Br 



If /i and/ 2 are introduced in equation (4a) ^we get 



»=M 1 fi ] / 1 (c,/»,T)+M i n Jl /i(c|>,T). . . (46) 



I£ we now add to oo a small quantity A% = da; we get a new 

 element of the same capacity as the original (see fig. 1). 



Fig. 1. 



■>k 



ac 



On the average the pressure will be a different one in this 

 element, and besides the mixture proportion will also be 

 different. Supposing the numbers of molecules of the new 

 element were n 1 -hdn i and n 2 -\-dn 2 , this will involve the 

 following change in the concentration 



7 / dn-i . d?i 2 \ 



dc = c\ — — - + — |. 



V ii 1 n 2 J 



(6) 



If we leave out quantities of the second and higher orders, 

 we get for the thermodynamic potential of the second 

 element 



M 



<o f =a> + Mx/irfw! + M 2 f 2 dn 2 + M^/^- 1 ■*" c 



+ MM 



* Dulieni ; loc. cit. tome iii. livre vi. p. 5. 





