Béguyer De Chancourtois, Alexandre-Émile

(b. Paris, France, 20 January 1820; d. Paris, 14 November 1886)

geology.

A grandson of René-Louis-Maurice Béguyer de Chancourtois, a noted artist and architect, Alexandre Émile entered the École Polytechnique in 1838 and the École des Mines in 1840. At the age of twentythree he left the latter to travel through Armenia, Turkestan, the Banat, and Hungary, and became involved in the exploration and study of their mountainous regions.

He returned to the École des Mines in 1848 as professor of descriptive geometry and subsurface topology, and retained his affiliation with this institution until his death. Here he met Élie de Beaumont, whose geological theories greatly influenced him. Béguyer became professeur suppléant to Élie in 1852, succeeding him as professor of geology in 1875. Élie, who headed the French Geological Survey, had his protégé named assistant director, and together they undertook an exploration of the Haute-Marne regions. This venture resulted in Béguyer’s publication in 1860 of a geological map of that region (drawn by M. Duhamel) as well as his collaboration with Élie on Études stratigraphiques sur le départ de la Haute-Marne (1862). The latter work contained a detailed study of the geological distribution of certain mineral deposits (sulfur, sodium, chlorine, the hydrocarbons); according to Élie’s theories, they should have been found in particular mineralogical, petrographic, and geological association.

Generalizing further from Élie’s ideas, Béguyer formulated a method for classifying chemical elements based “in the last analysis upon the distribution of these elements in the crust of the globe.” His scheme, a precursor of the periodic table, was put forth in “Vis tellurique, classement des corps simples ou radicaux au moyen d’une système de classification helicoïdal et numérique” (1862). The model for his theory was the “telluric screw,” a helical graph wound about a cylinder. The base of the cylinder was divided by sixteen equally spaced points, and the screw thread was similarly divided on each of its turns; the seventeenth point was on the second turn directly above the first, the eighteenth above the second, and so forth. Each point was supposed to represent the “characteristic number” of some element that could be deduced from its physical properties or chemical characteristics. Actually, Béguyer used unit equivalent weights as characteristic numbers, following Prout, who made hydrogen the unit. These weights were derived by measuring the specific heat of each element in a manner suggested by Regnault.

When placed on the telluric screw, elements whose equivalent weights differed by sixteen units were aligned in vertical columns. Sodium, for example, with a weight of 23, appeared one thread above lithium, with a weight of 7; potassium was above sodium, manganese above potassium. To the right of these columns was the group containing magnesium (24), calcium (40), iron (56), strontium (88), uranium (120), and barium (152). Directly opposite this group on the screw, oxygen (16) was aligned with sulfur (32), tellurium (128), and bismuth (224). One could, Béguyer believed, draw helices of any pitch through any two characteristic numbers of elements in different columns and find relationships among the elements so connected. Contrasts and analogies in mineralogical associations of the elements would become apparent through the sequences of their characteristic numbers along these helices. He showed that a line passed through magnesium and potassium (associated in the micas) would unite them, just as a line through sodium and calcium would show an association confirmed in the feldspars. If such lines were extended through or near the characteristic numbers of other elements, one would also be able to relate them to these mineral groups.

The name “telluric screw” was suggested to Béguyer by several circumstances, “especially the position of tellurium in the middle of the table and at the end of a characteristic series” and by the geognostic origin of his ideas, “since tellus refers to globe in the most positive and familiar sense, in the sense of Mother Earth.”

Despite an unfortunate lapse into numerology and several errors in determining equivalent weights, “Vis tellurique” may be said to have anticipated Mendeleev’s periodic table. When describing the theoretical origins of his work, Mendeleev mentioned that he was aware of Béguyer’s ideas among others; he further acknowledged that his own periodic classification was influenced to some extent by his knowledge of previous systems.

Béguyer made still other contributions to geology. He worked with Le Play in organizing the Universal Exposition of 1855. Prince Napoleon, who had been interested in the exposition and was pleased by its success, invited Béguyer to participate in the voyage of the Reine Hortense to the polar regions the following year. In 1875 Béguyer was appointed directors general of mines in France and initiated programs for the safety of miners and engineers. He also advocated the use of stereographic and gnomonic projections and campaigned for the adoption of a uniform system of cartographic gradation based on the metric system.

Béguyer served as secretary of Prince Napoleon’s Imperial Commission for the 1867 Universal Exposition. He also organized the French geological exhibits at the expositions in Venice (1881) and Madrid (1883), and was chef de cabinet during Prince Napoleon’s administration of Algeria and the African colonies.

A man of diverse interests, Béguyer attempted to develop a universal alphabet. He also studied human geography, trying to see if there was any consistent relationship between the geology of a country and the life style of its people. He devoted a great deal of time and effort to the improvement of the geological collections of the École des Mines and, finally, he toyed with ideas for using imaginary numbers in physics.

BIBLIOGRAPHY

1. Original Works. Béguyer contributed nearly 75 memoirs and notes, which may be found in Comptes rendus de l’Académie des sciences (1844–1864); Annales des mines (1846); and Bulletin de la Société géologique (1874–1884). Among his works are “Sur la distribution des minéraux de fer,” in Comptes rendus de l’Académie des sciences, 51 (1860), 414–417, the text accompanying Duhamel’s map; Études stratigraphiques sur le départ de la Haute-Marne (Paris, 1862); and. most important, “Vis tellurique,” in Comptes rendus de l’Académie des sciences, 54 (1862), 757–761, 840–843, 967–971.

II. Secondary Literature. Works on Béguyer are Roman D’Amat, “Béguyer de Chancourtois,” in Dictionnaire de biographie française, V (1951), 1279; and Léon Sagnet, “Chancourtois,” in La grande encyclopédie X (1890), 495.

Martha B. Kendall