24 AKT. 12. H. HIEOBE : ON THE FUSION SURFACES OF THE 



temperatures. In the next place the points having these values 

 of X (the empirical molar fraction of naphthalene) are taken on 

 the corresponding straight lines in the triangular diagram of 

 Plate II, and connecting all the points of the same temperatures 

 we get the isotherms. 



These are shown in the figure and are all convex towards N. 

 The diagram thus obtained is the horizontal projection of the 

 fusion surftice. Suppose these isothermal curves to be elevated 

 to proper heights according to the temperature, and imagine a 

 surface passing through all these isothermal curves, then ^ve get 

 the fusion surface under consideration. The surface on the whole 

 has a negative curvature, only a small portion near the apex 

 and next the line JVF has a ^^ositive curvature being convex 

 towards the corner N. 



E. The. Fusion Surface of Phenol. 



The fusion surface of phenol was determined in a similar 

 manner, and the experimental data are given in the following 

 five tables. 



TABLE 9. 

 Fusion Curve A. 



Naphthalene-phenol. Solid phase : phenol. 



No. t n Jt X p N P x' 



1 40.29° _ _ _ _ _ _ 1.0000 



2 3.5.79° 1.004 0.41 0.13 10.74 .00784 .1143 0.9357 



3 32.26° 1.957 0.68 0.23 10.64 .01529 .1132 0.8809 



4 30.05° 2.577 0.87 0.31 10.56 .02014 .1123 0.8485 



5 29.42° _ _ _ _ _ — (0.838) 



