Johan Georg Forchhammer (26 July 1794 – 14 December 1865) was a Danish

mineralogist Mineralogy is a subject of geology specializing in the scientific study of the chemistry, crystal structure, and physical (including optical mineralogy, optical) properties of minerals and mineralized artifact (archaeology), artifacts. Specific s ...

and

geologist A geologist is a scientist who studies the structure, composition, and History of Earth, history of Earth. Geologists incorporate techniques from physics, chemistry, biology, mathematics, and geography to perform research in the Field research, ...

Early life and education

Forchhammer was born at

Husum Husum (, ) is the capital of the ''Kreis'' (district) Nordfriesland in Schleswig-Holstein, Germany. The town was the birthplace of the novelist Theodor Storm, who coined the epithet "the grey town by the sea". It is also the home of the annual i ...

Schleswig The Duchy of Schleswig (; ; ; ; ; ) was a duchy in Southern Jutland () covering the area between about 60 km (35 miles) north and 70 km (45 mi) south of the current border between Germany and Denmark. The territory has been di ...

. He studied at the universities of

Kiel Kiel ( ; ) is the capital and most populous city in the northern Germany, German state of Schleswig-Holstein. With a population of around 250,000, it is Germany's largest city on the Baltic Sea. It is located on the Kieler Förde inlet of the Ba ...

and

Copenhagen Copenhagen ( ) is the capital and most populous city of Denmark, with a population of 1.4 million in the Urban area of Copenhagen, urban area. The city is situated on the islands of Zealand and Amager, separated from Malmö, Sweden, by the ...

from 1815 to 1818.

Career

Forchhammer then joined

Hans Christian Ørsted Hans Christian Ørsted (; 14 August 1777 – 9 March 1851), sometimes Transliteration, transliterated as Oersted ( ), was a Danish chemist and physicist who discovered that electric currents create magnetic fields. This phenomenon is known as ...

and Lauritz Esmarch in their mineralogical exploration of

Bornholm Bornholm () is a List of islands of Denmark, Danish island in the Baltic Sea, to the east of the rest of Denmark, south of Sweden, northeast of Germany and north of Poland. Strategically located, Bornholm has been fought over for centuries. I ...

, and took a considerable share in the labors of the expedition. In 1820 he obtained his

doctorate A doctorate (from Latin ''doctor'', meaning "teacher") or doctoral degree is a postgraduate academic degree awarded by universities and some other educational institutions, derived from the ancient formalism '' licentia docendi'' ("licence to teach ...

by a chemical treatise ''De mangano'', and immediately after set out on a journey through

England England is a Countries of the United Kingdom, country that is part of the United Kingdom. It is located on the island of Great Britain, of which it covers about 62%, and List of islands of England, more than 100 smaller adjacent islands. It ...

Scotland Scotland is a Countries of the United Kingdom, country that is part of the United Kingdom. It contains nearly one-third of the United Kingdom's land area, consisting of the northern part of the island of Great Britain and more than 790 adjac ...

and the

Faroe Islands The Faroe Islands ( ) (alt. the Faroes) are an archipelago in the North Atlantic Ocean and an autonomous territory of the Danish Realm, Kingdom of Denmark. Located between Iceland, Norway, and the United Kingdom, the islands have a populat ...

. In 1823 he was appointed lecturer at Copenhagen University on

chemistry Chemistry is the scientific study of the properties and behavior of matter. It is a physical science within the natural sciences that studies the chemical elements that make up matter and chemical compound, compounds made of atoms, molecules a ...

and

mineralogy Mineralogy is a subject of geology specializing in the scientific study of the chemistry, crystal structure, and physical (including optical mineralogy, optical) properties of minerals and mineralized artifact (archaeology), artifacts. Specific s ...

; 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 Denmark is a Nordic countries, Nordic country in Northern Europe. It is the metropole and most populous constituent of the Kingdom of Denmark,, . also known as the Danish Realm, a constitutionally unitary state that includes the Autonomous a ...

. On the death of Hans Christian Ørsted in 1851, he succeeded him as director of the polytechnic school and secretary of the Academy of Sciences. In 1850 he began with

Japetus Steenstrup Johannes Japetus Smith Steenstrup FRS(For) HFRSE (8 March 1813 – 20 June 1897) was a Danish zoologist, biologist, and professor. Life Born in Vang, Thy on 8 March 1813, he held a lectorate in mineralogy in Sorø until 1845 when he became a ...

and

Jens Jacob Asmussen Worsaae Jens Jacob Asmussen Worsaae (14 March 1821 – 15 August 1885) was a Danish archaeologist, historian and politician, who was the second director of the National Museum of Denmark (1865–1874). He played a key role in the foundation of scientifi ...

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 favorite 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 Rosenborg and the boring of

artesian well An artesian well is a well that brings groundwater to the surface without pumping because it is under pressure within a body of rock or sediment known as an aquifer. When trapped water in an aquifer is surrounded by layers of Permeability (ea ...

s. In 1865, Johan Georg Forchhammer conjectured that the ratio of major

salt In common usage, salt is a mineral composed primarily of sodium chloride (NaCl). When used in food, especially in granulated form, it is more formally called table salt. In the form of a natural crystalline mineral, salt is also known as r ...

s in samples of seawater from various locations was constant. This constant ratio is known as Forchhammer's Principle, or the Principle of Constant Proportions. Forchhhammer's theory was proven correct in 1884 by Prof

William Dittmar William Dittmar (1833 – 1892) was a German-born scientist renowned as a chemical analyst. He was based largely in Scotland. He did much analytical work on the findings from the ''Challenger'' expedition. He was the first to confirm the Princip ...

following extensive analysis of sea-water samples taken during the

Challenger expedition The ''Challenger'' expedition of 1872–1876 was a scientific programme that made many discoveries to lay the foundation of oceanography. The expedition was named after the naval vessel that undertook the trip, . The expedition, initiated by W ...

. Among his more important works are ''Lærebog i. de enkelte Radicalers Chemi'' (1842); ''Danmarks geognostiske Forhold'' (1835); ''Om de Bornholmske Kulformationer'' (1836); ''Dit myere Kridt i Danmark'' (1847); ''Bidrag til Skildringer af Danmarks geographiske Forhold i deres Afhængighed af Landets indre geognostiske Bygning'' (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 The Royal Society, formally The Royal Society of London for Improving Natural Knowledge, is a learned society and the United Kingdom's national academy of sciences. The society fulfils a number of roles: promoting science and its benefits, re ...

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). He was a Commander of the

Order of the Dannebrog The Order of the Dannebrog () is a Denmark, Danish order of chivalry instituted in 1671 by Christian V of Denmark, Christian V. Until 1808, membership in the Order was limited to fifty members of noble or royal rank, who formed a single cla ...

, and was a member of the

Royal Danish Academy of Sciences and Letters The Royal Danish Academy of Sciences and Letters ({{Langx, da, Det Kongelige Danske Videnskabernes Selskab or ''Videnskabernes Selskab'') is a Danish academy of science. The Royal Danish Academy was established on 13 November 1742, and was create ...

from 1825. In 1863, he was elected a foreign member of the

Royal Swedish Academy of Sciences The Royal Swedish Academy of Sciences () is one of the Swedish Royal Academies, royal academies of Sweden. Founded on 2 June 1739, it is an independent, non-governmental scientific organization that takes special responsibility for promoting nat ...

. He died at

. He was the brother of

August Friedrich Wilhelm Forchhammer August Friedrich Wilhelm Forchhammer (18 December 1797 in Husum – 16 February 1870 in Kiel) was a jurist and historian from the Duchy of Schleswig. He was born in Husum. He was a brother of Johan Georg Forchhammer, and through him an uncle of Jo ...

, father of Johannes Nicolai Georg Forchhammer, and grandfather of

Johannes Georg Forchhammer Johannes Georg Forchhammer (22 May 1861 – 23 July 1938) was a Danish educator of the deaf, who was director of several deaf schools in Nyborg and Fredericia from 1891 to 1926. Born to a family of academics, in Aalborg, first training as a ...

Personal life

Christoffer Wilhelm Eckersberg - Portrait of Louise Christiane Fugl

Forchhammer married twice. He married Louise Christiane Fugl (1804–1831), a daughter of ''kancelliråd'' U. N. Fugl (1768 – 1817), in 1826. She died in 1831 and he then married her half-sister Emilie Mariane Fugl (1815 – 1882). They lived in the Professor's House at

Nørregade Nørregade (literally "North Street") is a street in central Copenhagen, Denmark, linking Gammeltorv in the south with Nørre Voldgade in the north. Landmarks in the street include Church of Our Lady, Bispegården, St. Peter's Church and ...

8–10 in Copenhagen from 1833 and until his death in 1865. Forchhammer's son

Johannes Forchhammer Johannes Nicolai Georg Forchhammer (20 March 1827 – 9 July 1909) was a Danish philologist. He was born in Copenhagen as a son of Johan Georg Forchhammer. He was a nephew of August Friedrich Wilhelm Forchhammer. He finished his secondary educati ...

(20 March 1827 – 18 July 1908), the only child from his first marriage, was a linguist and headmaster of Aalborg Cathedral School and

Herlufsholm Herlufsholm School () is a private day and boarding school by the River Suså in Næstved, about south of Copenhagen. Herlufsholm was founded in 1565 as a boarding school for "sons of noble and other honest men" on the site of a former Benedict ...

. Gis second marriage was without children. Forchhammer died on 14. December 1865 and is buried in

Assistens Cemetery An Assistens Cemetery () is a cemetery that functions as an expansion of another, older cemetery often in relation to a city church. Already by the end of the 17th century, Danish authorities deemed that the conditions for inner-city cemeteries we ...

Awards

Forchhammer was a member of the

from 1825. He was awarded the

in 1939 and was created Commander of the Order of the Dannebrog in 1860. He was elected as a member of the

American Philosophical Society The American Philosophical Society (APS) is an American scholarly organization and learned society founded in 1743 in Philadelphia that promotes knowledge in the humanities and natural sciences through research, professional meetings, publicat ...

in 1862.

Written works

* ''De mangano'', 1820 * "Danmarks Geognostiske Forhold", in ''Universitetsprogram'', 1835. * ''Det nyere Kridt i Danmark'', 1847. * ''Lærebog i Stoffernes Almindelige Chemie'', 1842. * ''De enkelte Radikalers Almindelige Chemie'', 1842 (textbook). * ''Bornholmske Kulformationer'', 1836. * ''De vigtigste Sætninger af den uorganiske Chemie'', 1838. * ''Bidrag til Skildringen af Danmarks geographiske Forhold i deres Afhængighed af Landets indre geognostiske Bygning'', 1858. * ''Om Søvandets bestanddele og deres Fordeling i Havet'', 1859. * ''Almenfattelige Afhandlinger og Foredrag'', 1869. * Selvbiografi i ''Universitetes Program'', November 1903.

References

External links

Johan Georg Forchhammer
at geni.com {{DEFAULTSORT:Forchhammer, Johan Georg 1794 births People from Husum 1865 deaths People from the Duchy of Schleswig Danish mineralogists 19th-century Danish geologists Members of the Royal Swedish Academy of Sciences Danish people of German descent Commanders of the Order of the Dannebrog International members of the American Philosophical Society