KOENIG, George Augustus, chemist, born in Willstedt, Baden, Germany, about 1845. He was graduated at the Carlsruhe polytechnic school in 1863 as a mechanical engineer, and then studied the, natural sciences, especially geology and mineralogy, at the universities of Heidelberg and Berlin, receiving the degree of Ph.D. from the former in 1867. Subsequently he spent a year at Freiberg, Saxony, where he devoted his attention to the practice of mining and metallurgy, and in October, 1868, he came to the United States. At first he was engaged in industrial chemistry, manufacturing sodium stannate from scrap tin, but in 1869 he became chemist to the Tacony chemical works in Philadelphia, for which corporation he examined mining property in Mexico, notably in the Botapelas district of Chihuahua. In 1874 he was appointed assistant professor of chemistry and mineralogy in the University of Pennsylvania, becoming acting professor of geology and mining in 1879, and professor of mineralogy and metallurgy in 1886. His scientific work includes the invention of chromometry or the application of complementary colors to the quantitative estimation of metals that are dissolved in known quantities of glass fluxes, the description of four new species of minerals, and the re-examination and more perfect determination of numerous other species, and the development of a method for freeing the silver from low-grade ores by the combined action of chlorine, a concentrated solution of salt and steam pressure, for which a patent was issued in 1880, but which failed of commercial success. He is a member of scientific societies, and was one of the Seybert commission appointed by the University of Pennsylvania to investigate spiritualism. Dr. Koenig's investigations have been published in the "Proceedings of the American Philosophical Society," in the "Journal" of the Philadelphia .academy of natural sciences, of which societies he is a member, and in other chemical journals at home and abroad.