Some Recent Developments in the Study of the Solid State.

SCIENCE: A Weekly Journal devoted to the Advancement of Science, edited by J. McKeen Cattell and published every Friday by THE SCIENCE PRESS Lancaster, Pa. Garrison, N. Y. New York City: Grand Central Terminal. Annual Subscription, $6.oo. Single Copies, i5 Cts. SCIENCE is the official organ of the American Association for the Advancement of Science. Information regarding membership in the association may be secured from the office of the permanent secretary, in the Smithsonian Institution Building, Washington, D. a. Entered as second-class matter July 18, 1928, at the Post Office at Lancaster, ]Pa., under the Act of March 8, 1879. VOL. LIX SOME RECENT DEVELOPMENTS IN THE STUDY OF THE SOLID STATE1