KOHLRAUSCH, kOrroush, Friedrich, German physicist: b. Rinteln, 14 Oct. 1840; d. Marburg, 1910. He studied at Erlangen and Gottingen, and was teacher (docent) at the Frankfort Physikalischer Verein (1864). He became assistant professor (1870) and was ap pointed professor, successively, of the Poly technikum, Zurich (1870); Darmstadter Poly technikum (1871), and at Wurzburg (1875) and Strassburg (1:::). He was appointed president of the P•ysikal•schtechnischen Ans talt (Imperial Physico-technical Institute) of Berlin (1895), and honorary professor of the Berlin University (1899). In 1905 he retired to reside at Marburg. His work was chiefly in the realm of electric currents, resistance, the constitution of galvanic currents, the defining of the Ohm and electrochemical equivalents, thermo-electricity and conductivity of heat, total reflection of light, elasticity of matter, and especially reaction of elasticity. He constructed
numerous magnetic and electric measuring in struments, a bifilar-magnetometer, an intensity vaNation meter, a vokmeter, a switch-rheostat, etc. His exposition of the most important methods of measurements in physics is ex pounded in his (Leitfaden der praktischen Physik' (Leipzig 1870; 10th ed., 1905), and (Lehrbuch der praktischen Mystic' (1910) which latter was a 10th revised edition. His work in the field of electrolysis has been termed °epoch-making?' He wrote also