GENTH, Frederick Augustus, chemist, born in Waechtersbach, Hesse-Cassel, 17 May, 1820. After attending the gymnasium in Itanau, he studied at the University of Heidelberg, under Liebig at Giessen, and finally under Bunsen at, Narburg, where he received the degree of Ph.D, in 1846. For three years he acted as assistant to Professor Bunsen, and soon afterward came to the United States, where he has since resided. In 1872 he was called to the chair of chemistry and mineralogy in the University of Pennsylvania, which place he still occupies. He has also held the office of chemist to the geological survey of Pennsylvania and also to the board of agriculture of that state. Professor Genth is a member of many scientific societies in the United States, and was elected in 1872 to membership in the National academy of sciences. Professor Benjamin Silliman, Jr., speaks of him as having "no superior in this country as an analytical chemist," and he has greatly enriched the literature of chemistry with his very many and careful analyses of minerals. His name is associated with the ammonia cobalt bases which he discovered in 1846, and, in joint authorship with Dr. Wolcott Gibbs, he has contributed to the "Smithsonian Contributions to Knowledge" a monograph on "Researches on the Ammonia-Cobalt Bases" (Washington, 1856). Professor Genth is the author of nearly 100 separate papers on subjects in chemistry and mineralogy, and has published " Tabellarische Ubersicht der wichtigsten Reactionen welche Basen in Salzen zeigen" (Marburg, 1845), also the same in relation to " Acids" (1845); "Minerals of North Carolina," being appendix "C" of the "Report on the Geology of North Carolina" (Raleigh, 1875): also "First and Second Preliminary Reports on the Mineralogy of Pennsylvania" (Harrisburg, 1875-'6), and "Minerals and Mineral Localities of North Carolina" (Raleigh, 1881).