SOLID SOLUTIONS 77 



Molecules Melting point Melting point 



C S CZ 6 (a) C.Cl.BrO (i - a) (oZw.) (caZc.) 



0-7005 02995 90-3 90-55 



0-5774 0-4226 91-61 91-81 



0-4109 0-5891 93-27 93-51 



0-2867 0-7133 94-59 94-78 



0-1791 0-8209 95-74 95-88 



0-0955 0-9045 96-67 96.74 



002OO 0-9800 97-49 97'5 



o i 97-71 (S a ) 



The same behaviour was found for some other pairs of 

 very similar bodies. Still exceptions are found * which 

 increase with the difference between the two melting points, 

 and the abnormally large depression to be expected in the 

 higher melting substance, when the difference of melting 

 points is great, does not occur, e.g., with carbazol and 

 phenanthrene. On the other hand, there is the character- 

 istic rise of melting point, observed by Kiister, e.g. for 

 /3-naphthol in naphthalene, accompanying the separation of 

 a mixture richer in /3-naphthol 2 in accordance with the 

 theory of solutions. It is so far not certain that Kiister 's 

 pairs of substances form any departure from the theory. 



3. Amorphous Solid Solutions. 



Amorphous solid solutions would well form the first 

 subjects of experiment in this department. Kiister 3 has 

 made experiments on the partition of ether between water 

 and caoutchouc, and he concluded with considerable proba- 

 bility from the results, that ether in caoutchouc has the 

 simple molecular weight when dilute, but double when 

 more concentrated. 



The choice is, however, limited by the facility amorphous 

 solids have of taking up substances in quite another way 

 than mixture or solution. Thus the absorption of gases and 



1 Garelli, Gazz. Chim. ital. 1894, u. 263. 



2 Brunni, Atti E. Accad. dei Lincei, 1892 (2), p. 138. 



3 Zeitschr.f. Pkys. Chem. 13. 457. 



