Eilhard Mitscherlich
Encyclopedia
Eilhard Mitscherlich was a German
chemist
, who is perhaps best remembered today for his law of isomorphism (1819), which states that compounds crystallizing together probably have similar structures and compositions. This relationship was used by Berzelius
in early attempts to assign relative masses to the elements.
) in the Lordship of Jever, where his father was pastor. His uncle, Christoph Wilhelm Mitscherlich
(1760–1854), professor at Göttingen, was in his day a celebrated scholar. He was educated at Jever under the historian Friedrich Christoph Schlosser
, when he went to Heidelberg in 1811, and devoted himself to philology
, giving special attention to the Persian language
. In 1813 he went to Paris
to obtain permission to join the embassy which Napoleon I of France
was sending to Persia.
The events of 1814 put an end to this, and Mitscherlich resolved to study medicine
in order that he might enjoy that freedom of travel usually allowed in the East to physicians. He began at Göttingen with the study of chemistry
, and this so arrested his attention that he gave up the journey to Persia. From his Göttingen days dates the treatise on certain parts of Eurasian history, compiled from manuscripts in the university library and published in Persian and Latin
in 1814, under the title Mirchondi historia Thaheridarum historicis nostris hucusque incognitorum Persiae principum.
In 1818 Mitscherlich went to Berlin
and worked in the laboratory of Heinrich Friedrich Link (1767–1851). There he made analyses of phosphate
s and phosphite
s, arsenate
s and arsenite
s, confirming the conclusions of Jöns Jakob Berzelius
as to their composition; and his observation that corresponding phosphates and arsenates crystal
lize in the same form was the germ from which grew the theory of isomorphism, which he communicated to the Berlin Academy in December 1819. In that year Berzelius suggested Mitscherlich to the Prussian education minister Karl vom Stein zum Altenstein
as successor to Martin Heinrich Klaproth
at Berlin. Altenstein did not immediately carry out this proposal, but he obtained for Mitscherlich a government grant to enable him to continue his studies in Berzelius' laboratory at the Karolinska Institutet in Stockholm
. Mitscherlich returned to Berlin in 1821, and in the summer of 1822 he delivered his first lecture as extraordinary professor of chemistry in the university, where in 1825 he was appointed ordinary professor. In 1823, he was elected a foreign member of the Royal Swedish Academy of Sciences
.
In the course of investigating slight differences discovered by William Hyde Wollaston
in the angles of the rhombohedra of the carbonate
s isomorphous with calc-spar, Mitscherlich observed that the angle in the case of calc-spar
varied with the temperature. On extending this inquiry to other allotropic crystals, he observed a similar variation, and was thus led, in 1825, to the discovery that allotropic crystals, when heated, expand unequally in the direction of dissimilar axes. In the following year he discovered the change, produced by change of temperature, in the direction of the optic axes of selenite. His investigation, also in 1826, of the two crystalline modifications of sulfur
threw much light on the fact that the two mineral
s calc-spar and aragonite
have the same composition but different crystalline forms, a property which Mitscherlich called isomorphism.
in 1827 and showed that its salt
s are isomorphous with the sulphates, while a few years later he proved that the same thing is true of the manganate
s and the sulfates, and of the permanganate
s and the perchlorate
s. He investigated the relation of benzene
to benzoic acid
and to other derivatives. In 1829-1830 he published his Lehrbuch der Chemie, which embodied many original observations. His interest in mineralogy
led him to study the geology
of volcanic
regions, and he made frequent visits to the Eifel
with a view to the discovery of a theory of volcanic action. He did not, however, publish any papers on the subject, though after his death his notes were arranged and published by Dr. J. L. A. Roth in the Memoirs of the Berlin Academy (Ueber die vulkanischen Erscheinungen in der Eifel und über die Metamorphie der Gesteine durch erhöhte Temperatur, Berlin, 1865).
Mitscherlich was an honorary member of almost all the great scientific societies, and received the gold medal from the Royal Society
of London
for his discovery of the law of isomorphism. He was one of the few foreign associates of the French Institute.
In December 1861 symptoms of heart disease
made their appearance, but Mitscherlich was able to carry on his academic work until December 1862. He died at Schöneberg
near Berlin in 1863 and was buried in the St Matthäus Kirchhof Cemetery in Schöneberg close to the (eventual) gravesites of Gustav Kirchhoff
and Leopold Kronecker
.
Mitscherlich's published papers are chiefly to be found in the Abhandlungen of the Berlin Academy, in Poggendorff's
Annalen, and in the Annales de chimie et de physique
.
The fourth edition of Mitscherlich's Lehrbuch der Chemie was published in 1844-1847; a fifth was begun in 1855, but was never completed. A complete edition of his works was published at Berlin in 1896.
Germany
Germany , officially the Federal Republic of Germany , is a federal parliamentary republic in Europe. The country consists of 16 states while the capital and largest city is Berlin. Germany covers an area of 357,021 km2 and has a largely temperate seasonal climate...
chemist
Chemist
A chemist is a scientist trained in the study of chemistry. Chemists study the composition of matter and its properties such as density and acidity. Chemists carefully describe the properties they study in terms of quantities, with detail on the level of molecules and their component atoms...
, who is perhaps best remembered today for his law of isomorphism (1819), which states that compounds crystallizing together probably have similar structures and compositions. This relationship was used by Berzelius
Jöns Jakob Berzelius
Jöns Jacob Berzelius was a Swedish chemist. He worked out the modern technique of chemical formula notation, and is together with John Dalton, Antoine Lavoisier, and Robert Boyle considered a father of modern chemistry...
in early attempts to assign relative masses to the elements.
Early life and work
Mitscherlich was born at Neuende (now a part of WilhelmshavenWilhelmshaven
Wilhelmshaven is a coastal town in Lower Saxony, Germany. It is situated on the western side of the Jade Bight, a bay of the North Sea.-History:...
) in the Lordship of Jever, where his father was pastor. His uncle, Christoph Wilhelm Mitscherlich
Christoph Wilhelm Mitscherlich
Christoph Wilhelm Mitscherlich was a German classical scholar. He wrote several books on ancient Greek literature.-References:*Sowerby, E.M. Catalogue of the Library of Thomas Jefferson, 1952, v. 1, p. 7....
(1760–1854), professor at Göttingen, was in his day a celebrated scholar. He was educated at Jever under the historian Friedrich Christoph Schlosser
Friedrich Christoph Schlosser
Friedrich Christoph Schlosser was a German historian.-Biography:He was born at Jever in the District of Friesland. He studied theology, mainly at Göttingen, and then tutored privately...
, when he went to Heidelberg in 1811, and devoted himself to philology
Philology
Philology is the study of language in written historical sources; it is a combination of literary studies, history and linguistics.Classical philology is the philology of Greek and Classical Latin...
, giving special attention to the Persian language
Persian language
Persian is an Iranian language within the Indo-Iranian branch of the Indo-European languages. It is primarily spoken in Iran, Afghanistan, Tajikistan and countries which historically came under Persian influence...
. In 1813 he went to Paris
Paris
Paris is the capital and largest city in France, situated on the river Seine, in northern France, at the heart of the Île-de-France region...
to obtain permission to join the embassy which Napoleon I of France
Napoleon I of France
Napoleon Bonaparte was a French military and political leader during the latter stages of the French Revolution.As Napoleon I, he was Emperor of the French from 1804 to 1815...
was sending to Persia.
The events of 1814 put an end to this, and Mitscherlich resolved to study medicine
Medicine
Medicine is the science and art of healing. It encompasses a variety of health care practices evolved to maintain and restore health by the prevention and treatment of illness....
in order that he might enjoy that freedom of travel usually allowed in the East to physicians. He began at Göttingen with the study of chemistry
Chemistry
Chemistry is the science of matter, especially its chemical reactions, but also its composition, structure and properties. Chemistry is concerned with atoms and their interactions with other atoms, and particularly with the properties of chemical bonds....
, and this so arrested his attention that he gave up the journey to Persia. From his Göttingen days dates the treatise on certain parts of Eurasian history, compiled from manuscripts in the university library and published in Persian and Latin
Latin
Latin is an Italic language originally spoken in Latium and Ancient Rome. It, along with most European languages, is a descendant of the ancient Proto-Indo-European language. Although it is considered a dead language, a number of scholars and members of the Christian clergy speak it fluently, and...
in 1814, under the title Mirchondi historia Thaheridarum historicis nostris hucusque incognitorum Persiae principum.
In 1818 Mitscherlich went to Berlin
Humboldt University of Berlin
The Humboldt University of Berlin is Berlin's oldest university, founded in 1810 as the University of Berlin by the liberal Prussian educational reformer and linguist Wilhelm von Humboldt, whose university model has strongly influenced other European and Western universities...
and worked in the laboratory of Heinrich Friedrich Link (1767–1851). There he made analyses of phosphate
Phosphate
A phosphate, an inorganic chemical, is a salt of phosphoric acid. In organic chemistry, a phosphate, or organophosphate, is an ester of phosphoric acid. Organic phosphates are important in biochemistry and biogeochemistry or ecology. Inorganic phosphates are mined to obtain phosphorus for use in...
s and phosphite
Phosphite
A phosphite is a salt of phosphorous acid. The phosphite ion is a polyatomic ion with a phosphorus central atom where phosphorus has an oxidation state of +3...
s, arsenate
Arsenate
The arsenate ion is AsO43−.An arsenate is any compound that contains this ion. Arsenates are salts or esters of arsenic acid.The arsenic atom in arsenate has a valency of 5 and is also known as pentavalent arsenic or As[V]....
s and arsenite
Arsenite
In chemistry an arsenite is a chemical compound containing an arsenic oxoanion where arsenic has oxidation state +3.The different forms of the anion are the next ones:* ortho-arsenite: AsO33-* meta-arsenite: AsO2-...
s, confirming the conclusions of Jöns Jakob Berzelius
Jöns Jakob Berzelius
Jöns Jacob Berzelius was a Swedish chemist. He worked out the modern technique of chemical formula notation, and is together with John Dalton, Antoine Lavoisier, and Robert Boyle considered a father of modern chemistry...
as to their composition; and his observation that corresponding phosphates and arsenates crystal
Crystal
A crystal or crystalline solid is a solid material whose constituent atoms, molecules, or ions are arranged in an orderly repeating pattern extending in all three spatial dimensions. The scientific study of crystals and crystal formation is known as crystallography...
lize in the same form was the germ from which grew the theory of isomorphism, which he communicated to the Berlin Academy in December 1819. In that year Berzelius suggested Mitscherlich to the Prussian education minister Karl vom Stein zum Altenstein
Karl vom Stein zum Altenstein
Karl Sigmund Franz Freiherr vom Stein zum Altenstein was a Prussian politician....
as successor to Martin Heinrich Klaproth
Martin Heinrich Klaproth
Martin Heinrich Klaproth was a German chemist.Klaproth was born in Wernigerode. During a large portion of his life he followed the profession of an apothecary...
at Berlin. Altenstein did not immediately carry out this proposal, but he obtained for Mitscherlich a government grant to enable him to continue his studies in Berzelius' laboratory at the Karolinska Institutet in Stockholm
Stockholm
Stockholm is the capital and the largest city of Sweden and constitutes the most populated urban area in Scandinavia. Stockholm is the most populous city in Sweden, with a population of 851,155 in the municipality , 1.37 million in the urban area , and around 2.1 million in the metropolitan area...
. Mitscherlich returned to Berlin in 1821, and in the summer of 1822 he delivered his first lecture as extraordinary professor of chemistry in the university, where in 1825 he was appointed ordinary professor. In 1823, he was elected a foreign member of the Royal Swedish Academy of Sciences
Royal Swedish Academy of Sciences
The Royal Swedish Academy of Sciences or Kungliga Vetenskapsakademien is one of the Royal Academies of Sweden. The Academy is an independent, non-governmental scientific organization which acts to promote the sciences, primarily the natural sciences and mathematics.The Academy was founded on 2...
.
Isomorphism
William Hyde Wollaston
William Hyde Wollaston FRS was an English chemist and physicist who is famous for discovering two chemical elements and for developing a way to process platinum ore.-Biography:...
in the angles of the rhombohedra of the carbonate
Carbonate
In chemistry, a carbonate is a salt of carbonic acid, characterized by the presence of the carbonate ion, . The name may also mean an ester of carbonic acid, an organic compound containing the carbonate group C2....
s isomorphous with calc-spar, Mitscherlich observed that the angle in the case of calc-spar
Calcite
Calcite is a carbonate mineral and the most stable polymorph of calcium carbonate . The other polymorphs are the minerals aragonite and vaterite. Aragonite will change to calcite at 380-470°C, and vaterite is even less stable.-Properties:...
varied with the temperature. On extending this inquiry to other allotropic crystals, he observed a similar variation, and was thus led, in 1825, to the discovery that allotropic crystals, when heated, expand unequally in the direction of dissimilar axes. In the following year he discovered the change, produced by change of temperature, in the direction of the optic axes of selenite. His investigation, also in 1826, of the two crystalline modifications of sulfur
Sulfur
Sulfur or sulphur is the chemical element with atomic number 16. In the periodic table it is represented by the symbol S. It is an abundant, multivalent non-metal. Under normal conditions, sulfur atoms form cyclic octatomic molecules with chemical formula S8. Elemental sulfur is a bright yellow...
threw much light on the fact that the two mineral
Mineral
A mineral is a naturally occurring solid chemical substance formed through biogeochemical processes, having characteristic chemical composition, highly ordered atomic structure, and specific physical properties. By comparison, a rock is an aggregate of minerals and/or mineraloids and does not...
s calc-spar and aragonite
Aragonite
Aragonite is a carbonate mineral, one of the two common, naturally occurring, crystal forms of calcium carbonate, CaCO3...
have the same composition but different crystalline forms, a property which Mitscherlich called isomorphism.
Later work and last years
In 1833 Mitscherlich made a series of careful determinations of the vapor densities of a large number of volatile substances, confirming the law of Gay-Lussac. He obtained selenic acidSelenic acid
Selenic acid is the chemical compound with the formula . It is an oxoacid of selenium, and its structure is more accurately described as .As predicted by VSEPR theory, the selenium center is tetrahedral, with a Se–O bond length of 161 pm...
in 1827 and showed that its salt
Salt
In chemistry, salts are ionic compounds that result from the neutralization reaction of an acid and a base. They are composed of cations and anions so that the product is electrically neutral...
s are isomorphous with the sulphates, while a few years later he proved that the same thing is true of the manganate
Manganate
In inorganic nomenclature, a manganate is any negatively charged molecular entity with manganese as the central atom. However, the name is usually used to refer to the tetraoxidomanganate anion, MnO, also known as manganate because it contains manganese in the +6 oxidation state...
s and the sulfates, and of the permanganate
Permanganate
A permanganate is the general name for a chemical compound containing the manganate ion, . Because manganese is in the +7 oxidation state, the permanganate ion is a strong oxidizing agent. The ion has tetrahedral geometry...
s and the perchlorate
Perchlorate
Perchlorates are the salts derived from perchloric acid . They occur both naturally and through manufacturing. They have been used as a medicine for more than 50 years to treat thyroid gland disorders. They are used extensively within the pyrotechnics industry, and ammonium perchlorate is also a...
s. He investigated the relation of benzene
Benzene
Benzene is an organic chemical compound. It is composed of 6 carbon atoms in a ring, with 1 hydrogen atom attached to each carbon atom, with the molecular formula C6H6....
to benzoic acid
Benzoic acid
Benzoic acid , C7H6O2 , is a colorless crystalline solid and the simplest aromatic carboxylic acid. The name derived from gum benzoin, which was for a long time the only source for benzoic acid. Its salts are used as a food preservative and benzoic acid is an important precursor for the synthesis...
and to other derivatives. In 1829-1830 he published his Lehrbuch der Chemie, which embodied many original observations. His interest in mineralogy
Mineralogy
Mineralogy is the study of chemistry, crystal structure, and physical properties of minerals. Specific studies within mineralogy include the processes of mineral origin and formation, classification of minerals, their geographical distribution, as well as their utilization.-History:Early writing...
led him to study the geology
Geology
Geology is the science comprising the study of solid Earth, the rocks of which it is composed, and the processes by which it evolves. Geology gives insight into the history of the Earth, as it provides the primary evidence for plate tectonics, the evolutionary history of life, and past climates...
of volcanic
Volcano
2. Bedrock3. Conduit 4. Base5. Sill6. Dike7. Layers of ash emitted by the volcano8. Flank| 9. Layers of lava emitted by the volcano10. Throat11. Parasitic cone12. Lava flow13. Vent14. Crater15...
regions, and he made frequent visits to the Eifel
Eifel
The Eifel is a low mountain range in western Germany and eastern Belgium. It occupies parts of southwestern North Rhine-Westphalia, northwestern Rhineland-Palatinate and the south of the German-speaking Community of Belgium....
with a view to the discovery of a theory of volcanic action. He did not, however, publish any papers on the subject, though after his death his notes were arranged and published by Dr. J. L. A. Roth in the Memoirs of the Berlin Academy (Ueber die vulkanischen Erscheinungen in der Eifel und über die Metamorphie der Gesteine durch erhöhte Temperatur, Berlin, 1865).
Mitscherlich was an honorary member of almost all the great scientific societies, and received the gold medal from the Royal Society
Royal Society
The Royal Society of London for Improving Natural Knowledge, known simply as the Royal Society, is a learned society for science, and is possibly the oldest such society in existence. Founded in November 1660, it was granted a Royal Charter by King Charles II as the "Royal Society of London"...
of London
London
London is the capital city of :England and the :United Kingdom, the largest metropolitan area in the United Kingdom, and the largest urban zone in the European Union by most measures. Located on the River Thames, London has been a major settlement for two millennia, its history going back to its...
for his discovery of the law of isomorphism. He was one of the few foreign associates of the French Institute.
In December 1861 symptoms of heart disease
Heart disease
Heart disease, cardiac disease or cardiopathy is an umbrella term for a variety of diseases affecting the heart. , it is the leading cause of death in the United States, England, Canada and Wales, accounting for 25.4% of the total deaths in the United States.-Types:-Coronary heart disease:Coronary...
made their appearance, but Mitscherlich was able to carry on his academic work until December 1862. He died at Schöneberg
Schöneberg
Schöneberg is a locality of Berlin, Germany. Until Berlin's 2001 administrative reform it was a separate borough including the locality of Friedenau. Together with the former borough of Tempelhof it is now part of the new borough of Tempelhof-Schöneberg....
near Berlin in 1863 and was buried in the St Matthäus Kirchhof Cemetery in Schöneberg close to the (eventual) gravesites of Gustav Kirchhoff
Gustav Kirchhoff
Gustav Robert Kirchhoff was a German physicist who contributed to the fundamental understanding of electrical circuits, spectroscopy, and the emission of black-body radiation by heated objects...
and Leopold Kronecker
Leopold Kronecker
Leopold Kronecker was a German mathematician who worked on number theory and algebra.He criticized Cantor's work on set theory, and was quoted by as having said, "God made integers; all else is the work of man"...
.
Papers
Johann Christian Poggendorff
Johann Christian Poggendorff , was a German physicist born in Hamburg.By far the greater and more important part of his work related to electricity and magnetism. Poggendorff is known for his electrostatic motor which is analogous to Wilhelm Holtz's electrostatic machine...
Annalen, and in the Annales de chimie et de physique
Annales de chimie et de physique
Annales de chimie et de physique is a scientific journal that was founded in Paris, France, in 1789 under the title Annales de chimie. One of the early editors was the French chemist Antoine Lavoisier. In 1815, it became the Annales de chimie et de physique, and was published under that name for...
.
The fourth edition of Mitscherlich's Lehrbuch der Chemie was published in 1844-1847; a fifth was begun in 1855, but was never completed. A complete edition of his works was published at Berlin in 1896.
Further reading
- Eilhard Mitscherlich: Prince of Prussian Chemistry by Hans-Werner Scuhtt, 1997, ISBN 0-8412-3345-4
- Obituary of Eilhard Mitscherlich in Proceedings of the Royal Society of London, volume XIII, 1864 (pages ix - xvi, near the end of the volume)