HINRICHS, Gustavus Detlef; chemist, born in Lunden, Holstein, Germany; 2 December, 1886. He was educated at the polytechnic school and at the university in Copenhagen, where he was graduated in 1860. Soon after the completion of his studies he came to the United States and settled in Iowa City, Iowa. In 1863 he was made professor of physical sciences in the Iowa state university, and professor of chemistry and toxicology in the medical department, and in 1868 he became chemist to the geological survey of the state. The Iowa weather service was organized by Professor Hinrichs in 1875, and was the first state weather set-vice in the United States. These college appointments he held until 1885, when by a combination of religious and political influences he was driven from his chairs. He received the degree of M.D. from the Missouri medical college in 1872, and is a member of scientific societies both in the United States and Europe. Professor Hinrichs has contributed a large number of papers in various branches of physics which have appeared in the scientific journals. During 1870 he edited "The American Scientific Monthly," and he has published in book-form "The Elements of Physics" (Davenport, 1870); " The Principles of Pure Crystallography" (1871); "The Elements of Chemistry and Mineralogy demonstrated by the Student's own Experiments " (1871); "The Principles of Chemistry and Molecular Mechanics" (1874); and "First Course in Qualitative Analysis " (1874).