FEUCHTWANGER, Lewis, chemist, born in Furth, Bavaria, 11 January 1805; died in New York City, 25 June 1876. He was the son of a mineralogist, and inherited a taste for natural science, to which he devoted special attention at the University of Jena. After receiving his doctor's degree there in 1827, he came to the United States in 1829, and settled in New York, where he opened the first German pharmacy, and also practiced medicine, being particularly active during the cholera epidemic of 1832. Subsequently he devoted his entire attention to chemistry and mineralogy, and became engaged in the manufacture and sale of rare chemicals. He introduced in 1829 the alloy called German silver, and was the first to call the attention of the U. S. government to the availability and desirability of nickel for small coins. In 1837 he issued, by permission of the U. S. government, a large quantity of one-cent pieces in nickel, and in 1864 he had struck off a number of three-cent pieces in the same metal, but they were not put into circulation.

After the great fire of 1846 he called the attention of the authorities of New York to the fact that saltpeter would explode under certain conditions. This statement created much discussion; the expression "Will saltpeter explode?" became a byword, and a play was acted at one of the theatres in which a character representing Dr. Feuchtwanger was presented. He made two large collections of minerals, one of which he exhibited in London at the World's fair in 1851, and the other, which he bequeathed to his daughters, was for a time on exhibition at the Museum of natural history in Central park, New York. Dr. Feuchtwanger was a member of scientific societies in this country and abroad, and contributed papers to Silliman's "American Journal of Science " and to the " Proceedings" of the American association for the advancement of science. He published a "Popular Treatise on Gems" (New York, 1838); "Elements of Mineralogy" (1839); " Treatise on Fermented Liquors " (1858); and "Practical Treatise on Soluble or Water Glass" (1870).