351 



When f.i. is K=^, then the concentration of the new substance 



in the vapour must be at least live times as lai-ge as in the liquid, 



that curve E is proceeding towards higher pressnres, starting from i. 



In order to define the direction of curve E we define the values 



of A, and A, according (9) from : 



1 + ;ij + ;i, = and P.^a-, -f A,;c, = 

 (11) then passes into: 



'dP\ X, (H,-H) - x^ {H,-H) 



\dJ\ 



,_ .... (38) 



by which the direction of curve E is defined. This direction, as 

 follows from (37), is dependent on the partition (.»;,:. fj of the new 

 substance between gas and liquid. Also it follows from (37) that 

 curve E must be situated between the curves {L) and (6r). 



We now add a new substance which forms mixed-crystals with 

 F, but which does not occur in the vapour. When we represent 

 its concentration in F and L by x and x^ then it follows from (29) 

 and (32): 



^ (Aa-) J/ = AjA'j — X and 2 {Xx)h =^ -V — f^,^i 

 consequently : 



RT{x—X,x,) ^ RT(x—^i,x^) 



It is apparent from (30) and (33) that ^j <C 1 ^"cl ix^^l, but 

 also that A, differs very little only from 1. It follows from (39): 



for - > fi. is {d'J% > and (dP)^ > ; 

 Curve E is situated then, f.i. like curve id in fig. 1 



for fi, >->A, is (dT),yO and (^P):.<0; 

 Curve E is then situated, f.i. like curve ie in fig. 1 

 for — <;•! is (c?7'):,<0 and ((/P).,<0; 



Curve E then is situated f.i. as curve if in fig. 1. 

 In order to define the direction of curve E we take in accordance 

 with (9): 



:S{X) = l -{- X^ ^ X, = and ^ (Lv) = x + X^x, — 0. 



With the values of A^ and A, which follow from this we find for (11) : 

 dP\ ^ X, {H,- H) - X { H,-H,) 



( 



