600 



dp b^p 



quantities in the determination of ^ = and - — = 0. The calcula- 



dv dv^ 



lions relating to this are pretty laborious, and were carried out in 

 a separate chapter (§ 5 p. 25 — 34) in the cited Teyler article (cf. 

 also the above cited paper in These Proc. of Aug. 31, 1909, p. 127 — 130). 

 We refer to this article, and give here only the results of the calcula- 

 tions — again making everything have reference to a single mole- 

 cular quantity. 



For y/c was found : 



• ^^ = '<"^Xï;;F^Yn' (^) 



in which 



(3) 



^\ hile 



A6 

 <P = {lhi'i) : (4) 



V — 6 

 (p. 26 and 29 loc. cit.). 



When Ah = and so also cp = 0, as van der Waals assumes, 

 even then remains : 



hrough which for Vk, with 



is. found: 



vjc = 36, X ^-^^ (2«) 



In this the factor 3 must of course be replaced by a smaller one 

 (e.g. 2,1), when 6 is a function of v, and varies between b^ and b^, 

 when V varies from oo to v^. 



With regard to the factor of 3bjc — which according to van der 

 Waals (referring namely to a single molecular quantity and 7iot to 

 a 1 -{- X times larger quantity) would remain constant = 1 (at least 

 by approximation) — we see immediately that this factor can differ 

 pretty considerably from unity. For /? = (only double molecules) 

 and iS = 1 fonly single molecules) the factor is properly =1, but 

 for [3 = Ya it has the minimum value Vs- And this deviation, which al- 

 ready amounts to 11 °/^, is still more pronounced when Ab is not =0, 

 but has e.g. a negative value. 



For RTk we have found (p. 31 loc. cit.), again referring to a 

 single molecular quantity: 



