LEVY

levy, auguste michel (1844- ), french geologist, was born in paris on the 7th of august 1844. he became inspector-general of mines, and director of the geological survey of france. he was distinguished for his researches on eruptive rocks, their microscopic structure and origin; and he early employed the polarizing microscope for the determination of minerals. in his many contributions to scientific journals he described the granulite group, and dealt with pegmatites, variolites, eurites, the ophites of the pyrenees, the extinct volcanoes of central france, gneisses, and the origin of crystalline schists. he wrote _structures et classification des roches eruptives_ (1889), but his more elaborate studies were carried on with f. fouque. together they wrote on the artificial production of felspar, nepheline and other minerals, and also of meteorites, and produced _mineralogie micrographique_ (1879) and _synthese des mineraux et des roches_ (1882). levy also collaborated with a. lacroix in _les mineraux des roches_ (1888) and _tableau des mineraux des roches_ (1889). levy (fr. _levee_, from _lever_, lat. _levare_, to lift, raise), the raising of money by the collection of an assessment, &c., a tax or compulsory contribution; also the collection of a body of men for military or other purposes. when all the able-bodied men of a nation are enrolled for service, the french term _levee en masse_, levy in mass, is frequently used.