15 January 1965
Vol 147, Issue 3655

About The Cover

Crystals of a salt, probably potassium acid acetate, in a 1-liter flask with a round bottom. The pattern was produced during the course of an experiment in which a solution of potassium acetate and acetic acid was being evaporated, under reduced pressure and with continuous rotation, for an entirely different purpose (about X 1.1). [Waldo E. Cohn and Photographic Services Department of Oak Ridge National Laboratory]