(b. Abbeville, France, 31 March 1777; d. Paris, France, 30 March 1861),
Cordier was a pioneer in the geological, technical, and economic analysis of French mines, particularly coal mines. He began the use of the polarizing microscope in the study of the constituents of rocks. As a counsellor of state and later a peer during the reign of Louis Philippe, he played an important role in the organization of French railroads, steamboat navigation, and road construction. For three decades he was president of the Conseil des Mines, which afforded him a powerful voice in French mining affairs.
After completing his early education at Abbeville, Cordier went to Paris in 1794 and entered the École des Mines in 1795. He was named engineer in 1797, and in 1798 he was selected by Dolomieu to accompany him to Egypt as a member of the scientific commission of the French expedition. Cordier was an English prisoner for a short time when the venture failed, and returned to France in 1799. He traveled through Belgium, Switzerland, Italy, and Spain until 1803, when he was assigned as engineer in the Department of the Apennines. He became divisional inspector of mines in 1810.
Two of Cordier’s early mineral surveys were “Statistique du département du Lot” and “Statistique minéralogique du département des Apennins.” These were detailed analyses of the terrain, geology, mineral deposits, and mining and metallurgical works of the two departments. In 1815 Cordier published the memoir “Description technique et économique des mines de houille de Saint-Georges-Chatelaison.” This important coal mining property had become the subject of litigation; and Cordier had been appointed as an expert to evaluate the condition of the mines for the court, so that it could judge the rights and interests of the parties involved. the editors of the Journal desmines termed Cordier’s work one of the most difficult and delicate missions with which an engineer of mines could be charged.
Also in 1815 Cordier published a complete survey of French coal mines and coal production, “Sur les mines de houille de France et l’importation des houilles étrangères.” He reported that coal consumption in France had doubled during the period 1789–1812, owing mainly to the substitution of coal for wood, and that French coal production had tripled in the same period because of the cessation of English coal imports. He advocated the continued exploitation of French coal mines to avoid the necessity of imports, to supply domestic needs during wartime, and to aid in gaining a more favorable balance of trade. He recommended a high tariff on imported coal to effect this policy; and, pointing out that transportation costs accounted for 75 percent of the price of coal in France, he urged that the roads, canals, and rivers be improved to lower shipping costs. The publication had important effects, inasmuch as all of Cordier’s suggestions became future governmental policy.
In 1816 Cordier published the memoir “Sur les substances minérales, dites en masse, qui servent de base aux roches volcaniques.” In it he reported the results of a study of volcanic rocks from active and extinct volcanoes and from volcanic terrains, the origin of which was contested by neptunists and plutonists. He reduced the rocks to powder by compression, separated the particles by flotation, examined the particles microscopically to determine thier forms, and employed chemical and magnetic tests to ascertain the pure crystallized minerals of which they were composed. Cordier concluded that the difference between the varieties of modern and ancient lavas were caused only by a very slight modification of their intimate textures and that the lavas of disputed origin were extremely similar in texture and mineralogical composition to modern lavas. His memoir, then, was an important step in the resolution of the basalt controversy.
In 1819 Cordier became professor of geology at the Muséum d’Histoire Naturelle, and in 1822 he was admitted to membership in the Académie des Sciences. In 1827 he published the memoir “Essai sur la température de l’intérieur de la terre.” From accumulated temperature observations at various depths in mines, Cordier estimated that the earth’s temperature increased one degree centigrade for each thirty to forty meters of depth. He concluded that the earth was fluid beyond a depth of 5,000 meters and that it was a cooled star. It followed that consolidation had taken place from the exterior to the interior and that the layers of primitive terrain closest to the surface were the most ancient, a condition that had not been admitted in geology up to that time but one that geological theory would have to take into account. Further, Cordier attributed the occurrence of volcanoes to the action of the earth’s internal high-temperature fluid. This theory remained popular until the discovery of radioactivity.
In 1830 Cordier entered the Conseil d’État of Louis Philippe, and in 1831 he became president of the Conseil des Mines. In this position he presided over all of the permanent and temporary commissions of the Ministry of Public Works having to do with the Corps of mines, a powerful and time-consuming stituation that provoked citics to remark that Cordier could not fulfill all of his responsibilites without adding several day to the week.
By ordinance of 7 November 1839, Cordier was named a peer of France; but he was active only in matters having to do with railways, steamboats, and highways. Throughout the entire early period of railway construction in France, he stoutly maintained the minority opinion that all railroads should be privately owned in perpetuity, that the companies should be freed of all governmental supervision, and that the government should subsidize part of the cost of railway construction. Owing to his heavy administrative duties, Cordier published few scientific memoirs after 1837.
The metamorphic aluminum silicate Cordierite was named for him by Haüy.
I. Original Works. Cordier’s scientific memoirs appeared principally in the Journal des mines, the Annales des mines, and the Journal de physique. The most important were “Statistique du département du Lot,” in Journal ds mines, 21 (1807), 445–474; 22 (1807), 5–62; “Statistique minéralogique du département des Apennins,” ibid., 30 . (1811), 81–134: “Description technique et économique desmines de houille de Saint-Georges-Chatelaison,” ibid., 37 (1815), 161–214, 257–300; “Sur les mines de houille de France et l’importation des houilles étrangères,” in Journal de physique, 80 (1815), 272–316; “Sur les substances minerales, dites en masse, qui sevent de base aux roches volcaniques,” ibid., 84 (1816), 135–161, 285–307, 352–386; and “Esai sur la température des l’intérieur de la terre,” in Mémoires de l’Academie des sciences, 7 (1827), 473–556.
II. Secondary Literature. On Cordier or his work, see H. F. Jaubert, Notice sur la vie et les travaux de M. Cordier (Paris, 1862); V. Raulin, Notice sur les travaux scientifiques de M. Cordier (Bordeaux, 1862); and C. A. Read, Notice sur la vie et les travaux de P. L. A. Cordier (Paris, 1862).
John G. Burke