531 



For the calculation of the vapour-densities use is made of the second 

 virial coefficient, as deduced from the measurements by H. Kamerlingh 

 Onnes and W. J. de Haas (Comm. No. 127c). 



►J 



oa 

 < 



I 



o 



X3 



o 



b 



T3 



> 

 Or 



.2* 



CO 

 > 



Or 



Or 



.2 c 



O 



U 



Cu 



E 



co 



o 



co CM 



00 <o co 



o CM, co 



r^ t- i^ 



— ' 't 

 in co 

 i^ i> 



— -^ — CTlCDCOO^O 



cococor—coo'— CM 



_ ^ ^ ^ -, cm' Csj CM 



Om m 



OOOIOOICOOOCO 

 TfCOCOt— 0»-H<OCO 



ooooor^cO'ij''*' 



Witii these data the values of tfv in table II are calculated. Under 

 O — 6' are given the differences between if>,.obs. and values of ip^ calcu- 

 lated from VAN DER Waals' formula 



xp, = A{l-t)B 

 where 



35 

 Proceedings Royal Acad. Amsterdam. Vol. XVII. 



