Karl Reichenbach, baron, a German naturalist, born in Stuttgart, Feb. 12, 1788, died in Leipsic, Jan. 19, 1869. He was educated at Tubingen. At the age of 16 he conceived the idea of establishing a new German state in one of the South sea islands; and for three years he devoted himself to this project, and had secretly formed a large association in Würtem-berg, when it was suppressed by the French authorities on suspicion that its real objects were political, and Reichenbach was imprisoned. In 1821 he became connected with Count Hugo of Salm in the management of chemical works, iron furnaces, and machine shops at Blansko, Moravia, from which he soon secured an ample fortune; and about this time the king of Würtemberg made him a baron. From 1830 to 1834 he was engaged in the investigation of the complicated products of the distillation of organic substances, and discovered among them several compounds of carbon and hydrogen, the existence and useful properties of which were before entirely unknown; among these are creosote, paraffine, eupion, pittacal, and capnomor.

He afterward entered upon an investigation of the manner in which the human system is affected by various substances, and was led to conceive the existence of a new imponderable agent, allied to electricity, magnetism, and heat, which emanates from most substances, and to the influence of which different persons are variously sensitive. Although he had given no attention to animal magnetism, the subject was inevitably encountered by him in these researches; which, however, he pursued independently of all experiments and theories that had been made in that department. He applied the term od to the new force, the existence of which he believed he had established, and published Physikalisch-physiologische Unter-suchungen über die Dynamide des Magnetis-mus, etc. (2d ed., 3 vols., Brunswick, 1849-'50; translated into English); Odisch-magnetische Briefe (Stuttgart, 1852 and 1856; French translation, Paris, 1854; translated into English by Drs. Ashburner and Gregory); Der sensitive Mensch und sein Verhalten sum Od (2 vols., Stuttgart, 1854); and Wer ist sensitiv, wer nicht? (Brunswick, 1856).