291 



dT Ja 



AH 



and AF is very small, curve (G) is ascending, starting from point i 

 fast vertically. In figs 3 and 4 tliis curve is drQ,wn vertically up- 

 wards; the double arrow indicates thai starting from /, it may run 

 either towards the right or to the left. ^ 



As the coefficient — (1 -\- a) L V' of the phase /y, is negative in 

 each of the cases a, b and c, in accordance with (19) curve (L,) ^ /^ 

 -\- L^ -\- G is going starting from point i towards lower pressures 

 (figs 3 and 4). 



In the cases a and b tiie coefficient (J -|- d) L H' of phase L, is 

 positive in equation (20) so that curve (//J is going, starting from 

 i, towards lower pressures (fig. 3). In the case c is [1 -\- a) A H' 

 negative and curve (L,) is going, therefore, starting from i, towards 

 higlier pressures (fig. 4). This is in accordance also with that which 

 follows from (18) viz. 



/dP\ _ A /ƒ' 



(.(Ty'A.-AF"'' 



Consequently we have defined the direction of the curves (Cr) and 

 (L,); fig. 3 is true for the cases a and b, fig. 4 for the case c. 



With the aid of (19) and (20) we should be able to determine 

 also tlie position of the curves (F) and (L,) and then we could 

 prove that the four curves are situated with respect to one another 

 as in figs 3 and 4. [Compare f. i. Communication XIII]. As we know, 

 however, the situation of the curves (G) and (LJ we can find the 

 position of curves (F) and (L,) much more easily by using the rule 

 for the position of the four monovariant curves of a binary equili- 

 brium [Compare Communication I fig. 2]. 



In accordance with this rule we must meet, when we go, starting 



Fig. 3. 



^. — -z 



% m % • 



F A ^. f 



Fig. 4. 



