( 645 ) 



Buchner's values have been borrowed from his thesis for the doctorate 

 (Amsterdam 1905); those of Cextnerszwer from a table by van Laar 

 (These Proc. VIII, p. 151); that of Smits has been calculated from his 

 determination: plaitpoint at 203° anda; = 0.015, (These Proc. VII, p. 179). 



and so when introducing for a the quadratic and for b the linear 

 function : 



f dT h \ _ 2a,, - 2a, 

 \TicdxJj~Q a x 



(4) 



Now it will not be too hazardous an estimation, when — keeping 

 in view that the formula for ether is C 4 H 10 O and for anthraquinone 

 C 14 H 8 2 — , we put the size of the anthraquinone molecule at about 

 two or three times that of the ether molecule ; so b 3 = 2b l a 3b . 



If we introduce this value and the value of , calculated by the 



Tkdx 



aid of equation (3), into equation (4), we obtain a value for a xv 



Assuming that the value of 1\ for anthraquinone is 2 X560°=1120°, 



we can find an a t from the ratio of the critical temperatures ot 



ether and anthraquinone, and the a for ether ; and with these quan- 



dT k 

 titles we can finally calculate the -^-j~ on the anthraquinone side 



from : 



(dTk\ _ 2a_ 



V Tkdx J x -e 1 



T k dx 



— 2a, 



b ±rJi 



