RENÉ ANTOINE FERCHAUPT, Sieur de, distinguished for his laborious researches in natural science, was born at Rochelle, of a good family, in 1683. After having finished his early education in the place of his birth, he studied philosophy at Poitiers, and civil law at Bourges; but he soon relinquished the latter to apply himself to mathematics, physics, and natural history. Having come to Paris, he was received into the Academy of Sciences in 1708. From that hour he was wholly employed in natural history, to which his inclination particularly led him; and his inquiries were not confined to any one department of the subject. His memoirs, observations, and discoveries on the formation of shells, spiders, muscles, the marine flea, the berry which affords the purple dye, and on the numbing power of the torpedo, excited the curiosity of the public, and early announced him as an able, curious, and entertaining naturalist. The French were indebted to him for the discovery of the turquoise mines in Languedoc. He also found out a substance, now used to give false stones a colour, which is obtained from a certain fish called in the French able or ablete, on account of its whiteness, and which is the bleak or blay of our writers. His experiments on the art of turning iron into steel, not previously known in France, obtained him a pension of 12,000 livres; and this reward was to be continued to the Academy to support the expense which might accrue in this art. His work on that subject, which first brought him into general notice, was entitled L'Art de Converser le Fer Forgé en Acier, et l'Art d'Aoudier le Fer Fondu, 4to, 1722. He continued his inquiries on the art of making tin and porcelain, and endeavoured to perfect the thermometers then in use. He composed a Histoire des Rivières Aurières de France, and made curious and important observations on the nature of flints, on fossil shells (whence is obtained in Touraine an excellent manure for land), and likewise on birds and insects. He adopted the method for preserving eggs practised from time immemorial in Greece and the islands of the Archipelago, which is to steep or immerse them in oil or melted fat. Another experiment, still more important, made by Reaumur, was the introduction into France of the art of hatching fowls and birds, as practised in Egypt, without covering the eggs. The climate of France proved too severe, however, for carrying out this experiment with entire success. Active, sedulous, and attentive, he was early in his study, often at six in the morning. Exact in his experiments and observations, he let no circumstance escape him. In society he was distinguished through life for his modest and agreeable behaviour. His probity, benevolence, and goodness of heart endeared him to his countrymen. He died in the seventy-fifth year of his age, on the 18th of October 1757. His death was the consequence of a fall, which happened at the castle of Barnardière on the Maine, where he went to pass his vacation. He bequeathed to the Academy of Sciences his manuscripts and all his natural productions. His works consist of a very great number of memoirs and observations on different parts of natural history, printed in the collections of the Academy of Sciences; and a large work, printed separately in 6 vols. 4to, entitled Memoirs pour servir à l'Histoire des Insectes, 1734–42. (See Life of Reaumur by Cuvier, in the Biographie Universelle.)