Magnus, Heinrich Gustav (hĪnˈrĭkh gŏsˈtäf mägˈnŏs) [key], 1802–70, German chemist, physicist, and educator. In 1831 he became lecturer and in 1834 professor of physics and technology at the Univ. of Berlin. A brilliant and highly popular teacher, Magnus introduced the seminar and the teaching laboratory and was influential in the science of his time. The scope of his interests was broad; he was the first to prepare a platino-ammonium compound (Magnus's green salt) and several acids and their salts. From his study of projectiles was developed the theory of the "Magnus effect," the lateral force on rotating cylinders in air currents. His other investigations included studies in thermoelectricity, electrolysis, and vapor pressure.