Eilhard Mitscherlich

Eilhard Mitscherlich ( born January 7, 1794 in Neuende, now a district of Wilhelmshaven; † August 28, 1863 in Berlin) was a German chemist and mineralogist. He became known among other things as the discoverer of isomorphism and polymorphism in crystals and the selenium acid and the permanganic.

Life and work

Eilhard Mitscherlich was born on January 7, 1794 in the second parsonage at the so-called Walk of the Dead in the then to rule Jever belonging parish Neuende. He was baptized on 12 January 1794 in the Protestant St. Jakobi Church Neuende. Mitscherlich attended from 1800 to 1803 / 1804, the einklassige parish school of his native village Neuende, where his father was Carl Gustav Mitscherlich 1790-1826 Protestant pastor. He then went from 1804 to 1811 at the Latin school in the provincial school Jever 20 kilometers away, where he was inter alia Student of Friedrich Christoph Schlosser. At the age of 17 he left the Frisian Jeverland to take a study of history, philology and Oriental Studies at the Ruprecht -Karls- University of Heidelberg, Heidelberg. There he joined the Corps in 1813 Guestphalia Heidelberg.

After two years' residence in Heidelberg, he moved to Paris to see the hope of the Ecole des langues orientales better study conditions. As Napoleon Bonaparte intended to send an embassy to Persia, to Mitscherlich offered the opportunity to participate in mind to study conducting at the source of his language studies. The collapse of the French Empire broke up this opportunity, but without Mitscherlich stop its desire for a trip to the Orient.

Because he believed that he had as a doctor a better chance of a longer stay in Persia, he decided to study medicine, but still continue with the intention of the Orient his language studies. The inclusion of medical studies in 1814 in Göttingen was a turning point in his life. Here he became a member of the Corps Bremensia. The chemical research in the course of his studies handcuffed him so much that he gave up his language studies. Friedrich Stromeyer also advised Mitscherlich to a study of chemistry. Nevertheless, he acquired knowledge in his success to date his doctorate in 1818 at the University of Göttingen in specialist Oriental languages ​​( Persian).

In 1818 he went to Berlin for the botanist Heinrich Friedrich Link. In 1819, Jöns Jakob Berzelius was appointed after the death of Martin Heinrich Klaproth in Berlin. Berzelius suggested Mitscherlich as successor for this professorship in Stockholm and gave him time to prepare for a professorship in Berlin. After his return he was appointed in 1822 as professor of chemistry at the Friedrich- Wilhelms-Universität in Berlin. At the same time he became a member of the Royal Prussian Academy of Sciences. In the course of his career, he was also a professor of physics and chemistry at the Military Academy and was official commissions with words and deeds.

Mitscherlich died in August 1863 in Berlin -Schöneberg from a heart condition. He was buried in a mausoleum representative on the Old St. Matthew Cemetery. Mitscherlich's grave is recognized as an honorary grave of Berlin. The mausoleum was decorated with, among others, the original plaster of begun by Christian Daniel Rauch and completed by his pupil Elisabet Ney bust Mitscherlich. The 1990 on the occasion of their presentation at the exhibition " ethos and pathos " in the " Berlin Hamburger Bahnhof " restored bust is now secured the property of the cemetery administration.

Scientific work

In 1818 he observed that Kaliumarsenat and potassium phosphate crystallized in the same crystal form and in the solution of another salt grew crystals of a salt in the same structure. Like he observed for magnesium sulfate, zinc sulfate, ferrous sulfate and alums. Therefore Mitscherlich considered as the discoverer of isomorphism (1819 ) and the dimorphism. In addition, his interest in geology and mineralogical problems of mining. He undertook crystal angle measurements and ordered the minerals into groups. He dealt with the volcanism and gave out the great chemistry textbook.

Mitscherlich developed a detection reaction for phosphorus, examined the oxidation states of manganese, determined the gas and vapor densities of substances, examined the water of crystallization to form salts and put considerations to the development of mineral resources and ore veins at.

In 1833 Mitscherlich heated benzoic acid in a calcium hydroxide solution. He was able to distill an oil that he ( later name: benzene ) gasoline called. Mitscherlich found a match with the already discovered by Michael Faraday in coal tar bicarburet of hydrogen (benzene ). He treated his " gasoline " with nitric acid and obtained the nitrobenzene. By dissolving the " gasoline ", he received the benzene and diphenyl sulfone. By the action of chlorine on benzene Mitscherlich could get a trichlorobenzene. By the action of sulfuric anhydride to benzoic he received the Benzoeschwefelsäure. On the Constitution of benzoic acid, there was at that time still unclear.

The found of Mitscherlich " gasoline " was renamed by Justus von Liebig in benzene in 1843. In the foreign literature ( frz: Benzene, English: benzene ) was obtained, the adapted name of Mitscherlich.

In 1834 Mitscherlich published a treatise on an apparatus for ether production. Ethanol was converted to diethyl ether and water, the sulfuric acid was used only as a contact. Also the decay of oxidized water through Mangansuperoxid, gold or silver, only one contact is needed to decompose the compound into water and oxygen gas. Furthermore, the sugar breaks down into alcohol, carbonic acid, acetic acid; of urea into ammonia and carbon dioxide. The addition of a ferment, which does not undergo conversion even, but it is necessary for such reactions at a certain temperature. Later Jöns Jakob Berzelius adopted the ideas of Mitscherlich. He called the ferments now catalytic force and the reaction catalysis.

Mitscherlich also developed the idea that yeast consists of microorganisms. As proof, he pointed out an experiment with yeast and sugar solution.

Using a process developed by him polariscope he examined in 1844, the optical properties of tartaric acid and racemic acid. They seemed to be identical, except that a solution of tartaric acid rotated the plane of polarized light to the right, while a racemic acid solution was optically inactive in all properties. Louis Pasteur dissolved the apparent contradiction by showing in 1848 that racemic acid is a racemic mixture of two optically active enantiomers of tartaric acid.

In the field of organic chemistry it is determined by many substances ( naphthalene, iodoform, uric acid, benzene ), the chemical composition. He also dealt with nitrobenzene, azobenzene and benzenesulfonic acid. He dealt with the ether formation by sulfuric acid as a catalyst, with fermentation processes in sugar solutions. He noted that during the fermentation process sugar ( glucose) is created and this sugar is different from cane sugar. He developed a polarimeter, with which he could examine the levorotatory fructose and the inversion of sugar by acid influence.

Honors

In 1828 he was chosen as the " Foreign Member " of the Royal Society, which honored him in 1829 with the Royal Medal. From 1860 he was a member of the Leopoldina.

On December 7, 1894 one hundred years after his birth, was dedicated to the proposal of the director of the University of Berlin Prof. Cochius before his long-term effect of a memorial site. The still image Eilhard Mitscherlich, made ​​in 1894 by the sculptor Carl Ferdinand Hartzer since 1919, stands in front of the central projection of the east wing of the Humboldt University in Berlin.

On May 28, 1896 copy of the monument, this time by the family Mitscherlich to the city of Jever was opened -given monument. The statue made ​​of copper succumbed to corrosion and was dismantled in 1963 due to disrepair and replaced by an approximately eight-ton boulder with a simple label. The head of the statue ended up in an adventurous way with a Hungarian restorer in Budapest, but without that it had come to an agreement of restoration. Since 2005, the Polish artist Gerard Grzywaczyk in Katowice was busy trying to create out of the still existent head and some other parts of the ancient statue in optical proximity to the Berlin monument, a new image for Jever. This second statue was made by means of a conveyor circuit involving the Mitscherlich family, situated in Jever and inaugurated on 6 September 2006.

Family

Eilhard Mitscherlich is the father of Gustav Alfred Mitscherlich ( Professor of Surgery ) and Alexander Mitscherlich ( Professor of Chemistry ), and thus the great-grandfather of the psychoanalyst Alexander Mitscherlich and the grandfather of Eilhard Alfred Mitscherlich ( soil scientist ). His daughter Clara Mitscherlich married Gustav Heinrich Wiedemann (Professor of Physics). His daughter Agnes Mitscherlich married Charles David Wilhelm Busch ( Professor of Medicine ). His great-grandchildren were the forest scientist Gerhard Mitscherlich and Mitscherlich Eilhard veterinarian.

Works

  • About the relation of the crystalline form of the chemical proportions. 3.Abh: About the artificial representation of the minerals from their constituents, . 4.Abh. :. different in two forms krystallieren, Academy of Sciences, Berlin 1822-1825.
  • Chemistry textbook, 2 volumes, 4th Edition, 1840-1848.
  • Volcanic phenomena of the Eifel, 1865.
  • About the gasoline and the connections of the same: read in the Academy of Sciences on February 6, 1834 Engelmann, Leipzig 1898 ( Digitized edition of the University and State Library Dusseldorf ).
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