749 



The curves Fl, Fk and Fs must, tlierefore, be fiidialcd with 

 respect to one anotlier as in fig. 1. 



When V<^v, therefore A is negative, thou it follows: 





(33) 



The point H and therefore also the point 6*, must be imagined, 

 however in this case, also in fig. 1 on the otiier side of F. In 

 agreement with (33j Fl comes then between the two other curves. 



Now we shall consider the solutionpath consisting of a straight line 

 of F under its own vapourpressure or in short the solutionpath of 7*^. 

 We take viz. the system F" -\- L -\- G, but we take care that the 

 quantity of vapour is always very small. On change of 7'theli(piid 

 traces a straight line going through F, which we have called the 

 solution- or cristallisationpath of F\ In fig. I three similar solution- 

 paths i^^if, FZ^, and FZ^ are drawn. 



Let us consider now the binary equilibrium F -\- L-\- (r. In tig. 2 

 its P, T-curve is represented by EFU, Q is the point of maximum- 

 pressure, H the point of maximumlemperature; F^ is the minimum- 

 meltingpoint, K the point of maximumsublimation of the compound. 

 aK is the sublimation-, Fd the meltingcurve. Curve FFÜ touches 

 Fd in F and aK in K. It is apparent from the direction of the 

 meltingcurve that we assume V^v in agreement with fig. 1. 



Fig. 2. 



When the solutionpath FZ in fig. 1 coincides with FU, its 

 PjT'-curve in fig. 2 is, therefore, represented by UKF; when FZ 

 coincides in fig. 1 with FE, it is represented in fig. 2 by EHF. 

 When the solutionpath FZ in fig 1 turns from the position FLf 



