German physicist; born in Brunswick June 29, 1801; died in Dresden Jan. 14, 1869; educated at the gymnasia of Wolfenb�ttel and Braunschweig, and the Berlin University (Ph. D. 1823). He was privat-docent at the Berlin University (1826-27); assistant professor of physics, geography, and mathematics at Breslau University (1827-50); professor there (1850). He wrote: "Dissertatio de Theoria Gasorum et Vaporum," Berlin, 1823; "Popul�re Astronomie," Brunswick, 1827-29; "De Crystallorum Coh�sione," Breslau, 1829; "Die Lehre von der Coh�sion," ib. 1835; "Krystallisation und Amorphie," ib. 1852; and "Zur Krystallkunde. I. Characteristiken der Krystalle," Leipsic, 1869; also numerous papers in various professional journals.