( 456 ) 



and the parts which could be realised in different binary systems, 

 the line was generally divided by me into two branches according 

 as the coexisting liquid contained more A or more B than the 

 compound. 



/" 



Fig. I 



In figure 1 branch 1 : CTRF represents liquids with more A and 

 branch 2 : FD liquids with more B. 



At the commencement, special attention was called to the impor- 

 tant fact that in the first branch a maximum pressure occurs at T 

 where the heat of transformation of the three phases passes through 

 zero. Less attention was paid to the fact that the maximum tempe- 

 rature R does not completely coincide with the point F, where the 

 composition of the liquid becomes the same as that of the compound, 

 but is situated either on branch 'J, if the compound expands when 

 melting, or on branch 2 if the reverse is the case ; this may be best 

 understood if one remembers that the melting point line of the com- 

 pound FK meets the three-phase line in the point F. Although indi- 

 cated in the first publication of van der Waals and in my more 

 extended paper ^) this point remained in the background because, 

 practically, the difference in temperature between F and R is very 

 small. Afterwards ^), Van der Waals worked it out more carefully 

 and only recently Smits ^) has fully considered the peculiarities of the 

 7?,.7?-figures between F and R, after these had become important 



1) Rec. 5, 339, 340, 356, 1886. 



2) Verslag ICon. Akad. April 1897. 

 ^) These Proc. June 1905. 



