MICHEL-LÉVY, AUGUSTE (1844–1911), French petrologist and mining engineer. Michel-Lévy, who was born in Paris, was appointed director of the French geological survey and national inspector of mines in 1874. He was also a professor at the Collège de France. The most distinguished petrologist of his time, he was the first scientist to use the polarizing microscope to examine magmatic rocks and minerals. He extended this work by laboratory experiments in melting and crystallization, and with his collaborator F. Fouqué, was the pioneer of experimental petrology. He formulated fundamental queries which continue to pose major problems in the discussion of magmatic process as, for example, the role of volatiles (1875) and the mode of emplacement of granitic magmas through the assimilation of country rocks and bed-by-bed injection. The Fouqué-Lévy system became the standard one in the French teaching of petrography. Together with Fouqué, Michel-Lévy wrote Minéralogie micrographique (1879), Synthèse des minéraux et des roches (1882), and Structure et classification des roches éruptives (1889). He was a member of the French Academy.
This distinction was also conferred on his son, ALBERT-VICTOR (1877–1955), also a petrographer. He was born in Autun. Albert-Victor's main research was on the composition of the Vosges mountain range. He succeeded in producing artificial metamorphism in rocks by using pressure at high temperatures.