1911 Encyclopædia Britannica/Dufrénoy, Ours Pierre Armand Petit

DUFRÉNOY, OURS PIERRE ARMAND PETIT (1792–1857), French geologist and mineralogist, was born at Sevran, in the department of Seine-et-Oise, in France, on the 5th of September 1792. After leaving the Imperial Lyceum, in 1811, he studied till 1813 at the École Polytechnique, and then entered the Corps des Mines. He subsequently assisted in the management of the École des Mines, of which he was professor of mineralogy and afterwards director. He was also professor of geology at the École des Ponts et Chaussés. In conjunction with Élie de Beaumont he in 1841 published a great geological map of France, the result of investigations carried on during thirteen years (1823–1836). Five years (1836–1841) were spent in writing the text to accompany the map, the publication of the work with two quarto vols. of text extending from 1841–1848; a third volume was issued in 1873. The two authors had already together published Voyage métallurgique en Angleterre (1827, 2nd ed. 1837–1839), Mémoires pour servir à une description géologique de la France, in four vols. (1830–1838), and a Mémoire on Cantal and Mont-Dore (1833). Other literary productions of Dufrénoy are an account of the iron mines of the eastern Pyrenees (1834), and a treatise on mineralogy (3 vols. and atlas, 1844–1845; 2nd ed., 4 vols. and atlas, 1856–1859), in which the geological relations as well as the physical and chemical properties of minerals were dealt with; he likewise contributed numerous papers to the Annales des mines and other scientific publications, one of the most interesting of which is entitled Des terrains volcaniques des environs de Naples. Dufrénoy was a member of the Academy of Sciences, a commander of the Legion of Honour, and an inspector-general of mines. He died in Paris on the 20th of March 1857.