1911 Encyclopædia Britannica/Thomsen, Hans Peter Jörgen Julius

THOMSEN, HANS PETER JÖRGEN JULIUS (1826–1909), Danish chemist, was born in Copenhagen on the 16th of February 1826, and spent his life in that city. From 1847 to 1856 he was engaged in teaching chemistry at the Polytechnic, of which from 1883 to 1892 he acted as director, and from 1856 to 1866 he was on the staff of the military high school. In 1866 he was appointed professor of chemistry at the university, and retained that chair until his retirement from active work in 1891. His name is famous for his researches in thermochemistry, and, especially between 1869 and 1882, he carried out a great number of determinations of the heat evolved or absorbed in chemical reactions, such as the formation of salts, oxidation and reduction, and the combustion of organic compounds. His collected results were published in 1882–1886 in four volumes under the title Thermochemische Untersuchungen, and also a résumé in English under the title Thermochemistry in 1908. In 1857 he established in Copenhagen a process for manufacturing soda from cryolite, obtained from the west coast of Greenland. He died on the 13th of February 1909. His brother, Carl August Thomsen (1834–1894), was lecturer on technical chemistry at the Copenhagen Polytechnic, and a second brother, Thomas Gottfried Thomsen (1841–1901), was assistant in the chemical laboratory at the university till 1884, when he abandoned science for theology, subsequently becoming minister at Norup and Randers.