Hydrates in Aqueous Solution . Evidence for the existence of hydrates in solution, their approximate composition, and certain spectroscopic investigations bearing upon the hydrate problem. By Harry C. Jones, with the assistance of F. H. Getman, H. P. Bassett, L McMaster and H. S. Uhler. Pp. viii + 264. Publication No. 60 of the Carnegie Institution, Washington, D. C., 1907.