1144 



In the same way we find that in a P, y'-diagrain the binary 

 sohitionciirve under its own vapourpressiire of F' proceeding from 

 tlie qiiadrnplepoint, therefore, curve F' -\- />„ -f- G^, and the curve of 

 the ternary equihbrium F -\- F' -\- L -\- G proceeding from this point 

 touch one anotlier when 



(39) 



We can summarise the previous results in the following way. We 

 imagine a P, J'-diagram with the quadruplepoint F^ -\- F' -\- L ^ -\- G^, 

 the four ti'iplecurves proceeding from this point and the curve of the 

 ternary equilibrium F -\- F^' -\- L -\- (r proceeding from tiiis point. 

 This last curve touches in the quadruplepoint: 



the binary (congruent or incongruent) meltingcurve of i^+i^' 



^curve F-\- F' -\- //„) when j — J = oc 



the binary (congruent or incongruent) sublimationcurve oïF-\-F' 

 (curve F-i- F' + G,) when T-") = 



the binary solutioncurve under its own vapourpressure of F 

 (curve i^ + ^0 + ^^'o) vvhen (38) is satisfied 



the binary solutioncurve under its own vapoui'pressure of F' 

 (curve F' -\- L^ -\- G^) when (39) is satisfied. 



The above considerations apply of course also to the ternary 

 cryohydric curves under their own vapourpressure. As in a binary 

 cryohydric point under its own vapourpressure the equilibrium 

 F -\- Ice -\- Lq ^ G^ occurs and as from this point the ternary 

 cryohydric curve F -\- Ice -\- L -\- G proceeds, we have to replace 

 only F' by Ice in our previous considerations. Then we must equate 

 /?' to in (18) — (2J), (25) and (26); we then may summarise our 

 previous results in the following way : 



The cryohydric point of a substance is always lowered by addition 

 of a new substance when we keep the pressure constant; generally 

 this is also the case when this addition takes place under its own 

 vapourpressure. In the latter case the temperature, however, may 

 also firstly increase a little, before it decreases; this may take place 



however only then, when the limitraiio ( — j of the new substance 



in F -{- Ice -\- L^-\- G^ is very large and when the volume increases 

 at the formation of liquid from F -\- Ice. 



The vapourpressure of the cryohydric point, may, according to the 



value of ( — ) by addition of a new substance either decrease im- 



