CLARKE, Frank Wigglesworth, chemist, born in Boston, Massachusetts.. 19 March, 1847. He was graduated at the Lawrence scientific school of Harvard in 1867, and became assistant in chemistry at Cornell during the first year of its existence. In 1873-'4 he was professor of chemistry and physics at Howard University, Washington, District of Columbia, and in 1874 was called to fill a similar chair in the University of Cincinnati, where he remained until 1883. Under his direction the laboratory training" reached a high standard, and about thirty investigations were published as "Laboratory Notes." In 1883 he became chief chemist to the United States geological survey at Washington. Prof. Clarke has been active in the American association for the advancement of science, and in 1878 was chairman of the chemical section, delivering an address on "The Cultivation of Chemistry." During 1885 he was president of the Washington chemical society, and on retiring delivered an address on "The Relations of the Government to Chemistry." He has contributed frequent papers to the "American Journal of Science," "American Chemist," "American Chemical Journal," and to the "Proceedings of the American Association for the Advancement of Science." His most important work is the "Constants of Nature" (Washington, 1873, 1876, and 1882), in five octavo pamphlets, of which the last bears the sub-title of "A Recalculation of the Atomic Weights," the results in which are accepted as standard. He has published "Weights, Measures, and Money of all Nations " (New York, 1875); "Elements of Chemistry" (1884); and a "Report on the Teaching of Chemistry and Physics in the United States" (Washington, 1881). Prof. Clarke has also contributed popular essays on scientific subjects to " Appletons' Journal" and the "Popular Science Monthly."