Forchhammer, Johann Georg (1794-1865), Danish mineralogist and geologist, was born at Husum, Schleswig, on the 24th of July 1794, and died at Copenhagen on the 14th of December 1865. After studying at Kiel and Copenhagen from 1815 to 1818, he joined Oersted and Lauritz Esmarch in their mineralogical exploration of Bornholm, and took a considerable share in the labours of the expedition. In 1820 he obtained his doctor’s degree by a chemical treatise De mangano, and immediately after set out on a journey through England, Scotland and the Faeroe Islands. In 1823 he was appointed lecturer at Copenhagen University on chemistry and mineralogy; in 1829 he obtained a similar post in the newly established polytechnic school; and in 1831 he was appointed professor of mineralogy in the university, and in 1848 became curator of the geological museum. From 1835 to 1837 he made many contributions to the geological survey of Denmark. On the death of H.C. Oersted in 1851, he succeeded him as director of the polytechnic school and secretary of the Academy of Sciences. In 1850 he began with J. Steenstrup and Worsaae various anthropological publications which gained a high reputation. As a public instructor Forchhammer held a high place and contributed potently to the progress of his favourite studies in his native country. He interested himself in such practical questions as the introduction of gas into Copenhagen, the establishment of the fire-brigade at Rosenberg and the boring of artesian wells.
Among his more important works are—Loerebog i de enkelte Radicalers Chemi (1842); Danmarks geognostiske Forhold (1835); Om de Bornholmske Kulformationer (1836); Dit myere Kridt i Danmark (1847); Bidrag til Skildringen af Danmarks geographiske Forhold (1858). A list of his contributions to scientific periodicals, Danish, English and German, will be found in the Catalogue of Scientific Papers published by the Royal Society of London. One of the most interesting and most recent is “On the Constitution of Sea Water at Different Depths and in Different Latitudes,” in the Proceedings of the Roy. Soc. xii. (1862-1863).
