( 18Ö ) 



MR2 

 P = T- 



MRT{l—x) ö, (1— .<■)' 



and 



V 6j (1 — x) 



MRTx a^x' 

 P2 



V — 6j X v^ 



and from this by approximation 



2 MRTb,, X n—x) — 2a,„ x (1 —x) 



^P^v- (ft + ft) = -"-^ — i^ ^^ ^ 



(1 + at) b,„ — «,„ 

 Lp = 2 \" ^ ^- (1-^) . 



If we first restrict ourselves, when discussing- the value of A/j, 

 to this approximative formula, which is sufficiently accurate under 

 a small pressure, we see 1". that Ap varies greatly with the density, 

 that it is even proportional to the square of the density; 2°. that 

 Ap depends on the composition of the mixture in the same way 

 as A« , and 3°. that the sign of A;, depends on the sign of 

 {I -\-at) b^^ — Oj^. This expression cannot be considered as small, 

 and does by no means disappear, when the two components are 

 the same. 



In this case b^^ = Z», and «,2 =^ a^ and the value of A,, is also 

 of the same order as the deviation of the pressure in the investigation 

 of the law of Boyle, and varies also inversely as the square of 

 the volume. Also for Ay, there is a temperature, at which it is 0, 

 just as is the case with p — />', if />' is the pressure according to 

 the law of Boyle and p the observed pressure. Below this tempe- 

 rature Ap is negative, above it, on the contrary it is positive. The 

 agreement of the course of Ap with that of />—/>', when the volume 

 gradually decreases, is nearly perfect. 



When the volume is continually decreasing, a maximum value 

 for p — p' is found in those cases, in which this difference is 

 negative foj' a large volume, and in this case a volume may be 



