Fouqué, Ferdinand André

(b. Mortain, Manche, France, 21 June 1828; d. Paris, France, 7 March 1904)

geology, mineralogy.

Fouqué made three important contributions to science. First, he added significantly to the knowledge of volcanic phenomena and volcanic products, in particular generalizing Henri Sainte-Claire Deville’s explanation of the chemical composition of the emanations of fumaroles. Second, in collaboration with Auguste Michel-Lévy, he introduced into France the study of rocks by microscopical petrography. Third, again in collaboration with Michel-Lévy, he successfully synthesized a large number of igneous rocks in an attempt to determine the conditions necessary for the production of their mineralogical constituents.

Fouqué had some difficulty in settling upon a career. He attended Saint-Cyr (1847), the École d’Administration (1848), and the École Normale Superieure (1849). He became a laboratory assistant at the latter and collaborated in 1853 with Sainte-Claire Deville in a memoir concerning the action of heat on topaz. After working briefly in the chemical industry, he commenced medical studies and received his doctorate in medicine in 1858. His lasting interest in volcanic phenomena was aroused when he accompanied Sainte-Claire Deville in 1861 to Vesuvius, then in eruption, to observe the fumaroles.

During the next twenty years, Fouqué traveled extensively to study volcanoes, both active and extinct. He was present at the eruption of Etna in 1865 and of Santorin (now Thíra, Greece) in 1866; and he investigated the volcanic chemistry of the Lipari Islands, Vesuvius, Solfatara, and the Cantal. His research resulted in several important publications: Recherches sur les phénomènes chimiques qui se produisent dans les volcans (1866), which was accepted as his thesis for the doctorate in physical sciences; Les anciens volcans de la Grèce (1867); and Santorin et ses éruptions (1879). His most important finding was that the chemical products of fumaroles are primarily a function of temperature, thus relating the product composition, the site of the fumarole with respect to the center of the eruption, and the elapsed time between the emergence of the vent and the beginning of the eruption.

Fouqué’s studies of volcanoes led naturally to his other scientific activity, in which he collaborated closely with Michel-Lévy. Both had heard of Henry Clifton Sorby’s work in the microscopical examination of thin sections of rocks, and they perfected this technique. Their two-volume work Minéralogie micrographique (1879) introduced this new petrographic method into France. Further, they laid the foundations of modern petrography by introducing a classificatory system based on the mineralogical composition, the structure, and the chemical composition of volcanic rocks.

From 1878 to 1882, Fouqué and Michel-Lévy worked continuously on the artificial synthesis of igneous rocks, primarily to determine the conditions surrounding their origins. They were successful in producing the majority of volcanic rocks with the identical mineralogical composition and structural peculiarities found in nature. Their work verified the importance of the rate of cooling on the extent of crystallization and the sizes of grain, and demonstrated that rocks of distinctly different mineralogical composition would be formed from the same magma, depending on the conditions of crystallization.

Fouqué received the Cuvier Prize in 1876, and in 1877 he became professor of natural history at the College de France. He was named to the French geological survey commission in 1880, and in this position he made contributions to the stratigraphic geology of the Haute-Auvergne region. He was elected to the Académie des Sciences in 1881 and presided over it in 1901. In 1884, following earthquakes in Andalusia, he directed a group sent there by the Institut de France to study these phenomena. This mission led to Fouqué’s experiments on the speed of propagation of shock waves in a variety of soils. His last important work, completed in 1896, was a petrographic study of the plagioclase feldspars.

BIBLIOGRAPHY

I. Original Works. Fouqué’s chief publications are Recherches sur les phénomènes chimiques qui se produisent dans les volcans (Paris, 1866); Les anciens volcans de la Grece (Paris, 1867); Santorin et ses éruptions (Paris, 1879); Minéralogie micrographique: Roches éruptives françaises, 2 vols. (Paris, 1879), written with A. Michel-Lévy; Synthèse des minéraux et des roches (Paris, 1882), written with A. Michel-Lévy; and Les tremblements de terre (Paris, 1888). He published approximately 100 memoirs, some in collaboration with Michel-Lévy.

II. Secondary Literature. See A. Michel-Lévy, “Notice sur F. Fouqué,” in Bulletin de la Société française de minéralogie, 28 (1905), 38-56; and Alfred Lacroix, Notice historique sur Auguste Michel-Lévy (Paris, 1914).

John G. Burke