(242) 

 the öcpariitc volumes, we fiiul for it the t'ollowiiig expression : 



.r(l-.r) 



(^'1 - h) (1 - ^) + ("2 - *2).^ 



«1 h «2 2 ai3 



Uj (1 — X) + «2 X 



For volumes which are not too small, whicli do e. g. not descend 

 below 0,03, we might put by approximation 



(4') = r „ , , -.0 («1 - + «3 -^ - 2 «13) - 



- (61 + i-2 - 2 ij.) (l + «o{- 



If i>i and i'3 are left the same and only the value of j' is changed, 



{Ln)' is a maximum if -, = — . This leads to the rule, that 



the maximum value of (AyO', which for small values of p is found 

 in mixtures for which * = V2 , passes, when the pressure increases, 

 towards mixtures, in which that component is in excess which is 

 most compressible. As A„ reverses its sign, when the volume is 

 very small, this must also be the case for (A;;)' • 



If aj — ij (1 + « t) = , the first component follows the law of 

 Boyle. In the same way the second component, if 03— ^3(1 + «0 = 0' 

 If «13— ii3(l + at) = the law of Dalton holds good. And finally 

 if (ai + 02—2 «io) — (Z»i + ^3 — 2 ^12) {V-\- at)z='d , there is no 

 variation of volume, and the law of Amagat holds true. All this 

 only in the supposition of large gasvolumes. Let us call the tempe- 

 ratures, at which these four relations are fulfilled : ta, h, tc and t^. 

 If ta"^ tb~^ ic , then td > tc . The supposition «a > ^6 > tc is fulfilled, 

 if the two components can form mixtures, the critical temperature 

 of which lies below that of the components '). Then t^ is the lowest 

 of these four special temperatures. 



1) Moleculurtlieorie, Pbys. Cbem. V. 2, p. 149. 



