78 



ART. 10. K. IKEDA : STUDIES ON THE 



or P=>T,C« + ;rß(7ß+{l + (v-l)6y(l-a;);r,+ {l + (v-l)(7ß}(;r,-;r,)2/. 



As Gx and Cp are independent of ?/, only the last term is 

 variable in the right side of this equation, when x is made 

 constant. Hence planes erected perpendicnlar to the plane of 

 composition and parallel to the axis of y must cut the surface 

 of the total pressure in straight 

 lines. This surface is therefore 

 a ruled surface as shown in 



Fig. Va. As -Q^ IS positive 



the inclination of the straight 

 lines must increase with in- 

 creasing X. The system ethyl 

 alcohol — benzene — carbon tetra- 

 chloride studied by Schreine- 

 MAKERS (Zeit, physik. Chem., 

 47, 445 ; 1904) appears to be 

 in qualitative agreement with 

 the foregoing result. Yet the 

 mutual relation between the 

 alcohol and the normal com- 

 ponents seems to be more complicated, the decrease of the 

 chemical potential on mixing being less than might be expected, 

 were the conditions of the quasi-ideal solutions fulfilled. 



The relation between the boiling point and the composition 

 will not be discussed in this place, because it is rather com- 

 plicated and there seems at present to be but scanty field for 

 application of the results to be obtained. 



