1911 Encyclopædia Britannica/Levy, Auguste Michel

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 éruptives (1889), but his more elaborate studies were carried on with F. Fouqué. Together they wrote on the artificial production of felspar, nepheline and other minerals, and also of meteorites, and produced Minéralogie micrographique (1879) and Synthèse des minéraux et des roches (1882). Levy also collaborated with A. Lacroix in Les Minéraux des roches (1888) and Tableau des minéraux des roches (1889).