Karl Casar Von Leonhard, a German geologist, born at Rumpelheim, near Hanau, Sept. 12, 1779, died in Heidelberg, Jan. 23, 1862. He was educated at Marburg and Gottingen, was employed in making several scientific journeys in different parts of Germany, and until 1814 held important offices in the administration of the principality of Hanau. Retiring from the service of the state to devote himself exclusively to study, he became in 1816 member of the Bavarian academy of sciences, and in 1818 professor of mineralogy and geology in the university of Heildelberg. His works in this department of science are very numerous, the latest being Grundzuge der Minera-logie (2d ed., I860). From 1830 to 1858 he edited, in conjunction with Bronn, the Jahr-buchfur Mineralogies Geognosie, Geologic und Petrefactenkunde. - His son Gustav, born in Munich, Nov. 22, 1816, is professor in the university of Heidelberg, and has published several works upon mineralogy and geology, among which are Die Mineralien Badens nach ihrem Vorkommen (2d ed., 1855), and Grund-zuge der Geognosie und Geologie (2d ed., 1863).