Henry Louis Le Chatelier died at Miribel-les-Echelles (Isère), France, on September 17th, 1936, at the age of 85.
He graduated from the École Polytechnique and the École des Mines in 1871, and after six years’ work as a mining engineer in the Corps des Mines, was appointed in 1877 to the chair of general chemistry at the Ecole Nationale Supérieure des Mines de Paris. After 1887, however, he confined his Work to industrial chemistry, and remained loyal to this branch of the subject until his retirement. On the death of Schutzunburger in 1898, be Chatelier succeeded to the chair of mineral chemistry at the College de-France, and in 1907 he followed Moissan as Professor of this subject at the Sorbonne. He also held the post of Inspector-General of Mines under the French Government. In 1878, shortly after taking up his first professional appointment, he was appointed a member of a commission to investigate colliery accidents caused by firedamp, and his work had several important results, including the determination of the temperature of ignition of gas-air mixtures, the distinction between ignition and flame propagation, an explanation of the function of the metallic gauze in safety lamps, and a description of the appearance of the lamp-flame in the presence of varying proportions of firedamp. His work in the course of this enquiry laid the foundations of modern safety regulations for gassy mines. In 1887 he and Mallard (who had been his colleague on the previous enquiry) undertook research on safety explosives, which demonstrated the unsuitability of black powder in gassy mines, and prepared the way for the adoption of ammonium nitrate as a principal ingredient in mine explosives.
At this period also he carried out his work on the specific heats of gases at high temperatures, and on the properties of hydraulic mortars and cements. The results of these latter researches formed the subject of his doctorate thesis in 1887. His greatest contribution to science was his work on the subject of chemical equilibrium. In a series of memoirs published from 1885 onwards he forged the link between chemistry and thermo-dynamics, enunciated the principles of chemical equilibrium and its associated phenomena, and for the first time gave expression to Gibbs’ Phase Rule. These conceptions were of paramount importance, not only in the field of theoretical science, but also in the domain of industrial chemistry.
His researches on the synthesis of ammonia, begun in 1900, were of fundamental importance in the subsequent development of the process on an industrial scale, The study of reversible reactions revealed to him the urgent necessity for a precise method of measuring high temperatures, and to him we owe the perfection and application of the thermo-electric couple, supplemented later by an optical pyrometer. Quite apart from its significance in industrial technique, the pyrometer enabled him to extend the range of his researches, particularly in the study of metals and alloys. Valuable conceptions were formulated in a classic memoir on the theory of the tempering of steel, published in 1897.
His published works include those on Industrial Heating, Carbon and Combustion, and Silica and Silicates. In 1904 the Revue de Métallurgie was founded through his efforts, and he published much of his work in its pages. He was a Grand Officer of the Legion of Honour, a Member of the Academy of Sciences, an Honorary Doctor of many Universities, and a Foreign Member of the Royal Society.
Professor Le Chatelier was elected an Honorary Member of the Institution in 1916.
Vol. 46, Trans IMM 1936-7, pp.825-6
