REAUMIIR, Rrri ANTOINE FEIICIIAULT DE, a celebrated naturalist and physicist, was horn at La Rochelle, iu the department of,Charente-Inferieure, France, Feb. 28, 1683; and studied in the Jesuits' college at Poictiers and afterward at Bourges. With an eye, observant of facts of every kind, and an indiscriminate thirst for information, he yet specially devoted his attention to physics, natural history, and mathematics. In 1703 lie went to reside at Paris, where he speedily attracted general attention by the publica tion of three geometrical memoirs on particular cases of intersection of lines; and in 1708 he was elected a memher of the academy of sciences, and was chitiged with the supervision of the work Description des dicers Arts et ,Iliticrs, published under the aus pices of the government. Bilaumur lightened his labors with occasional researches into various subjects of natural history. These researches occupied him from 1708 to 1715, and were followed by a series of investigations into the condition of the woods, gold bearing rivers, and turquois mines of France. Ills investigations into the nature of the turquoises of Languedoc led him to the discovery, that they consisted of the fossil teeth of extinct animals. The collections of memoirs of the academy of sciences from 1722 till 1725 contain a number of papers by Hemaninur, in which he details his discoveries of the mode of producing steel from iron (an art till that time unknown in France), of the tendency which fused metals have to become crystallized, and of the mode of tin ning iron (also till that time unknown in France). For these brilliant and valuable suc cesses, lie received from the French government a sum of 12;000 livres, which he spent in promoting and encouraging the industrial tuts in his native country. Iteaumur's volatile genius next prompted him to take up time subject of pottery; and here also his ingenuity and perseverance were rewarded with success, for though he failed in success fully imitating the porcelain of China, he succeeded in producing (1739) an opaque glass, which was equal to the porcelain of Saxony and Japan. All this time he occasionally
pursued his studies in natural history, at one time propounding a mode for preserving eggs (by coating them with fat), at another giving directions for the production of fowls by artificial incubation. His invention of the thermometer (q.v.) which bears his name need not be more than mentioned here. He died of a fall from a horse at his estate of in the department of Maine, Oct. 17, 1757, leaving behind him a volumin ous coilection of works on all the subjects above stated, also a treatise on " the silk of spiders," which was translated into Manchu by the command of the emperor of China; and a number of memoirs (1731140), containing his thermometric researches on air, and on mixtures of fluids with fluids or solids. But by far his most important work is the Itemoires pour sertir a l'Ilistoire des Insectes (Amsterdam, 12 vols. 1737148), which embodies a number of original observations and discoveries concerning the habits and instincts of insects,.sufticient of itself to immortalize their author. Only six volumes of this work have been published, the seventh being very incomplete at the period of the author's death. While collecting materials for this great worlr, he kept numerous insects of all kinds in his garden, in order to have every opportunity for observing them. The academy of sciences obtained, by the terms of Reaumur's will, his collections of minerals and plants; materials for a history of quadrupeds and birds, afterward made use of by Brisson and Button; a history of arts, in MS.; and an immense number of finished and unfinished MS. memoirs.