CHEMISTRY: WASHBURN AND READ 
191 
and into pyromucic acids under the same conditions as chondrosic acid, 
hence it was concluded that the two acids were similar in their structure, 
namely, that in both an oxygen bridge existed between the a- and ai-car- 
bon atoms.^ 
6. The anhydrodicarboxyKc acids (derived from hexoseamines) have 
as many asymmetric carbon atoms in their molecule as the corresponding 
acids derived from hexoses. Therefore, there are possible only two opti- 
cally inactive anhydrodicarboxyKc acids : namely, one corresponding to 
mucic and the other to allomucic acid. This consideration Kmits the 
possibilities of configuration of epichondrosic acid to anhydromucic, or 
anhydroallomucic. The fact that chondrosamine forms a phenyl osa- 
zone identical in its properties with that of allose decides the choice 
between the two configurations in favor of anhydroallomucic. 
7. Regarding the configuration of chondrosine the choice remains 
between that of /-allosamine or of /-altrosamine. Both anhydroallo- 
mucic and anhydrotalomucic acids are obtainable from chondrosamine 
depending on the procedure in preparation. 
It was attempted to prepare chondrosaminic acid synthetically from 
ribosimine by the action of prussic acid. The acid obtained in this 
manner had the composition of hexosaminic acid, C = 37.02%, H = 
6.58%, and N = 7.44%? (theory, C = 36.92, H = 6.66, N = 7.18). 
M. P. = 198°C., [a]jy = — 9.4°. The acid was evidently epimeric with 
chondrosaminic, and on treatment with nitric acid it should have 
yielded chondrosic acid. Unfortunately for lack of material this 
experiment had to be deferred. 
1 Fischer, E., and Leuchs, H., Berlin, Ber. D. chem. Ges., 36, 24 (1903). 
2 Irvine, J. C, and Hynd, A., London, J. Chem. Soc, 101, 1128 (1912); 105, 698 (1914). 
3 Levene, P. A., and La Forge, F. B., /. Biol. Chem., 18, 123 (1914). 
* Fischer, E., and Tiemann, F., Berlin, Ber. D. chem. Ges., 24, 2139 (1891). 
THE FREEZING-POINT-SOLUBILITY LAW FOR IDEAL 
SOLUTIONS 
By Edward W. Washburn and John W. Read 
LABORATORY OF PHYSICAL CHEMISTRY. UNIVERSITY OF ILUNOIS 
Presented to the Academy, February 19, 1915 
When a solution is formed by mixing together two completely miscible 
pure Kquids, it is found that when the two constituents resemble each 
other very closely the formation of the solution takes place without 
appreciable heat-effect or volume-change. Such solutions have been 
termed ideal solutions; and experiments have shown that the vapor pres- 
