36 



ART. 10. K. IKEDA : STUDIES ON THE 



the latter with respect to that 

 of the liquid. These curves are 

 straight lines, and the angle 

 which one of them makes with 

 the axis of Ci must have the 

 same sense as the angle which 

 the other line makes with the 

 same axis. Fig. 10 represents 

 these lines, with the conjugated 

 points connected by straight lines. 



Fia. 10. 



{b) The Relation betioeen the Temperature and the 

 Composition of the two Phases. 



Differentiating equation (20) with respect to T, 

 (J 



8 In 



Co 



RT 



ri It n 



8T =(-5=-^/')-«'"^, 



where Si", So", etc. are the molecular entropies of the solid 

 components. The right sides of the equations represent the 

 increase of entropy when one mol of each component passes 



from the solid to the liquid phase. When r^, r^, are 



not very large or very small the heat absorbed when one mol 



of Si, ©2» passes from the solid to the liquid solution is 



very nearly equal to the heat of fusion qx, q.,, , and we 



have 



