Johan Georg Forchhammer

Johann Georg Forchhammer ( born July 26, 1794 in Husum, † December 14, 1865 in Copenhagen) was a Danish mineralogist and geologist.

Life

His brother was Peter Wilhelm Forchhammer.

From 1815 to 1818, he studied in Kiel and Copenhagen. He accompanied Hans Christian Ørsted and Lauritz Esmarch (1765-1842) in the mineralogical study of Bornholm. In 1820 he received his doctorate in Kiel Dr. phil. with a thesis about manganese. In 1822 he was a lecturer at the University of Copenhagen and in 1823 lecturer of chemistry and mineralogy. Since 1825 he was a member of the Royal Danish Academy of Sciences. In 1829 he became professor of chemistry and mineralogy at the Polytechnic School and professor of mineralogy at the Maritime Academy in Copenhagen newly established. 1835-37 he published numerous works on the geology of Denmark and Scandinavia. In 1848 he was curator of the Geological Museum. In 1850 he worked with Iapetus Steenstrup and Jens Jacob Asmussen together Worsaae. 1851, after the death of Ørsted he took over his position as director of the Polytechnic School and secretary of the Academy. 1865 published a work on the composition of sea water, which is considered a milestone in chemical oceanography. He introduced the term salinity in seawater and identified some 27 elements. He claimed that the salinity in the various oceans while varying the relative proportions of the individual components but remained constant.