The New International Encyclopædia/Kohlrausch, Friedrich

KOHLRAUSCH, kōl'roush, Friedrich (1840—). A German physicist, born at Rinteln, the son of Rudolf Hermann Arndt Kohlrausch. His education was obtained at Erlangen and Göttingen. In 1866 he became professor at Göttingen, and subsequently was appointed to chairs at Zurich(1870), Darmstadt (1871), Würzburg (1875), and Strassburg (1888). In 1895 he was appointed president of the Imperial Physico-Technical Institute (Reichsanstalt) at Charlottenburg, near Berlin, and under his direction the work of this bureau has been widely extended and developed. Professor Kohlrausch has a brilliant record as an experimental physicist and has devised new apparatus and methods for measurements. His researches have embraced all departments, but those dealing with electricity and magnetism are of special importance. He has investigated most thoroughly the subject of electrolysis and has brought out new methods for the absolute measurement of resistance. The elasticity of solids and various problems in light have also been investigated by him, and he is the author of Leitfaden der praktischen Physik, which, published in 1872, has been issued in many editions and translated into English, being considered the standard work on physical laboratory methods and measurements. A ninth edition, enlarged and revised, was published in 1901 with the title of Lehrbuch der praktischen Physik. A more elementary work based on the above, Kleiner Leitfaden der praktischen Physik, has also appeared. Professor Kohlrausch is besides the author of Ueber den absoluten Leitungswiderstand des Quecksilbers (1888), and of many papers contributed to the Annalen der Physik und Chemie, and other scientific journals.