Moritz Ludwig Frankenheim

Moritz Ludwig Frankenheim (born June 29, 1801 in Braunschweig , † January 14, 1869 in Dresden ) was a German physicist , geographer and crystallographer .

Life

Moritz Ludwig Frankenheim was born in Braunschweig in 1801 and attended grammar school there and in Wolfenbüttel . After finishing school, he went to Berlin to study physics at the Alma Mater Berolinensis (today's Humboldt University ), which he completed in 1823 with the dissertation Dissertatio de Theoria Gasorum et Vaporum Meditationes . Driven by the research of his teacher there, Christian Samuel Weiss (1780–1856), his interest mainly shifted to crystallography . In 1827 he was appointed to the University of Breslau , where he was initially assistant professor for physics, geography and mathematics from 1827 to 1850, and finally full professor for these subjects from 1850. After his retirement he went first to Leipzig and then to Dresden, where he died in 1869 at the age of 67.

In 1841 he was elected a member of the Leopoldina .

Services

Frankenheim's main focus was crystallography, especially with regard to investigations into crystal morphology and work on the mathematical-theoretical background of the symmetry of crystals . As early as 1826 he used the integer reciprocal values ​​of the Weiss coefficients (the points of intersection of a plane with the three crystallographic axes) to describe the spatial position of crystal surfaces, from which the English crystallographer William Hallowes Miller (1801-1880) developed the Miller indices in 1839 . By assigning symmetry elements to the crystal systems previously defined by Weiss and Friedrich Mohs (1773–1839), Frankenheim succeeded for the first time in defining the 32 point groups (crystal classes) and dividing them into the then four crystal systems (the regular, the four-membered, the two-part and the six-part). From his observations, he derived 15 lattice types for crystals, which were later reduced to 14 by Auguste Bravais (1811–1863) and which still today describe the possible unit cells of crystal structures as Bravais lattices . Frankenheim was also one of the first to conduct microscopic examinations of crystals in polarized light , using the then still new Nicol prism as a polarizer .

In the field of geography, the book Völkerkunde from 1852 is one of his most famous works.

Works

• Dissertatio de Theoria Gasorum et Vaporum Meditationes. Berlin 1823.
• Crystallonomic essays. ISIS , Vol. 19, pp. 497-515 , 542-565 , Jena 1826.
• Popular astronomy. Brunswick 1827.
• De Crystallorum Cohesion. Wroclaw 1829.
• The doctrine of cohesion, including the elasticity of gases, the elasticity and coherence of liquid and solid bodies, and crystal science. Wroclaw 1835.
• System of crystals. Wroclaw 1842.
• Crystallization and amorphism. Breslau 1851.
• Ethnology. Wroclaw 1852.
• On the origin and growth of crystals according to microscopic observation. 1860.
• To crystal science. I. Characteristics of the crystals. Leipzig 1869.

literature

• José Lima-de-Faria (Ed.): Historical Atlas of Crystallography. Published for International Union of Crystallography by Kluwer Academic Publishers, Dordrecht et al. 1990, ISBN 0-7923-0649-X .
• Erhard Scholz : symmetry, group, duality. On the relationship between theoretical mathematics and application in crystallography and structural engineering of the 19th century (= Science Networks. Historical Studies. Vol. 1). Birkhäuser, Basel et al. 1989, ISBN 3-7643-1974-7 .
• Karl-Friedrich Seifert:  Frankenheim, Moritz Ludwig. In: New German Biography (NDB). Volume 5, Duncker & Humblot, Berlin 1961, ISBN 3-428-00186-9 , p. 350 ( digitized version ).

Web links

• The doctrine of cohesion on mineralogicalrecord.com (English)