Lewis, Gilbert N.

Lewis, Gilbert N. (Newton) (1875–1946) physicist, chemist; born in Weymouth, Mass. He taught chemistry at Harvard (1899–1906), joined the Massachusetts Institute of Technology (1907–11), then moved to the University of California: Berkeley (1912–46). He developed the valence theory of chemical reactions (1923). With his student, Harold Urey, he discovered "heavy" water (1933), and, in the same year, collaborated with E. O. Lawrence to invent the cyclotron. Lewis made fundamental contributions to acid-base theory, thermodynamics, and research on atomic structure and relativity. After 1941, he undertook studies of glaciation and early American civilization.