855 



limit-ratio of C is greator than that of A, the boilingpointcAirve 

 outs off a greater part from tlie side BC than tVoin tlie side 11 A. 



In the end A W,, and L W^ may have an opposite sign, so tiiat 

 the case sub h occurs. That there may be accordance with fig. 3, we 

 take A1K,>() and hW,, <^Q. From (11) it now follows that j^ 

 and 1] have the same sign, so that the boiling|)ointcnrve going through 

 B must be situated within the triangle. We see that this is in 

 accordance with fig. 3. 



If the pressure is a little raised, so that dP is positive, it follows 

 from (10) that the boilingpointcnrve cuts off a positive part i] from 

 the F-axis {BC) and a negative part ;^ from the A'-axis {BA). 

 If the pressure is lowered, so that dP is negative, then we find that 

 the curve cuts off a negative part >/ from the I'-axis {BC) and a 

 positive part 5 from the .V-axis {BA). If we imagine in fig. 3 some 

 boilingpointcurves still to be drawn in the vicinity of that going 

 through B and these extended outside the triangle as the sides AB 

 and CB, then we see that all this is in accordance with the previous 

 results. Considering oidy the parts of the curves, situated within the 

 triangle, it follows: the terminatingpoint of the boilingpointcnrve 

 going through the point B sliifts on decrease of /'* tVom B on the 

 side BA and on increase of P from B on the side BC. 



No\v we shall still examine how the temperature changes along a 

 boilingpointcnrve in the vicinity of the point B. ¥o\' this we choose 

 a boilingpointcnrve of a definite pressure Fjj -\- dl\ so that we must 

 assign a definite constant value to dP in (9). We then find : 



A W,, . dT= E-n r^^ -'"A^^ T . LV,, . dP . . (12) 



A W, . dT = RT T'^ —yAy^j^T.LV^.dP. . (13) 



As in (9) the temperature is put equal to Tjj -f dT, dP is, 

 therefore calculated from the point B. Desiring to proceed from 

 the terminatingpoint of the boilingpointcnrve on the }"-axis {BC), 

 we put dT:= dT';/ -\- dT,,; herein dT',f is the change of 7', wanted 

 to come from the point B in the terminatingpoint of the boiling- 

 pointcnrve on the F-axis and dT the change of temperature 

 from this terminatingpoint along the curve. We now have : 

 A W-, . dT'y = T . A V„ . dP. Substituting in (12; dT^ dT',, + dT,,, 

 we obtain : 



A W,, . dT,j = RT (yi-'^\% (U) 



When we represent the change of temperature along the boiling- 



55 

 Proceedings Royal Acad. Amsterdam. VlI. \V1. 



