Rene Antoine Ferchault, Sieur de, a person distinguished for his laborious researches into natural knowledge, was born at Rochelle in 1683, of a family belonging to the law. After having finished his early studies in the place of his birth, he began a course of philosophy at Poitiers, and of civil law at Reaumur Bourges; but soon relinquished the latter, to apply himself, according to his taste, to mathematics, physics, and natural history. Being 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 part of it. His memoirs, his observations, his discoveries on the formation of fleas, spiders, mussels, the marine flea, the berry which affords the purple colour, and on the cause of the numbness of the torpedo, excited the curiosity of the public, and early procured our author the character of an able, curious, and entertaining naturalist. Filled with zeal for the welfare and advantage of society, and the progress and perfection of arts, he endeavoured in all his researches to promote the public good. We were indebted to him for the discovery of the Turquoise mines in Languedoc. He also found out a substance, which is used to give false stones a colour, which is obtained from a certain fish called in the French Able or Athlete. **See Below** 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 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.

He continued his inquiries on the art of making tin and porcelain †, and endeavoured to render our thermometers more useful than those of former times; he composed a curious history of rivers where gold dust is found in France; and gave so simple and easy a detail of the art of gathering this dust, that persons have been employed for that purpose.

He also made curious and important observations on the nature of flints, on the banks of fossil shells, from whence is obtained in Touraine an excellent manure for land; as likewise on birds and their preservation, on their method of building nests; on insects; and a great number of other subjects, not less curious than useful.

He imagined at first, that a certain varnish would keep eggs fresh; but the waste of time and money, &c. showed him the inconveniences of such a process. He afterwards adopted the method practised for time immemorial in Greece and the islands of the Archipelago, which is to steep or immerse eggs in oil, or melted fat; by this means, not being exposed to the air or to frost, they are well preserved, and contract no bad smell. Another experiment still more important, made by our author, was to introduce into France the art of hatching fowls and birds, as practised in Egypt, without covering the eggs. Active, industrious, 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. His writings must be of great use to future philosophers. In society, he was distinguished through life for his modest and agreeable behaviour. His probity, benevolence, goodness of heart, and other amiable qualities, as well natural as acquired, endeared him to his countrymen. He died in the 76th year of his age, on the 18th of October 1757, and left this world filled with sentiments of piety. His death was the consequence of a fall, which happened at the castle of Barnardiere on the Maine, where he went to pass his vacation. He bequeathed to the Academy of Sciences his Reaumur his manuscripts and all his natural productions. His works are, 1. A very great number of memoirs and observations on different parts of natural history; they are printed in the collections of the Academy of Sciences. 2. A large work printed separately in 6 vols in 4to, intitled, A Natural History of Insects. This important work contains a description of vast numbers of caterpillers, moths, gall insects, flies with two and four wings, lady birds, and those ephemeron flies which live only in that form a few hours; and lastly, of those singular and wonderful insects which are called polyptes, which being cut into several pieces, each piece lives, grows, and becomes an insect, and affords to our eyes a great number of prodigies*. The works of M. de Reaumur are exact, curious, interesting, and very ingenious. They are written with much candour, clearness, and elegance; but it must be acknowledged his manner is somewhat too diffuse. But we must not deceive the reader; he often raises our expectations, and does not give us all the satisfaction we promise ourselves from his writings. His method of raising poultry, in particular, rather disappoints us. He spared neither care, time, nor expense, to render it practicable: he flattered himself and his countrymen with the greatest hopes; but notwithstanding his assiduous industry, and vast charges, it proved abortive. The late M. l'Advocat recommended him to obtain better information from Egypt on the subject; and if possible to procure a person versed in the art to instruct him in it; but his death prevented the completion of the scheme. If the native of Egypt had arrived, showed M. de Reaumur a better method than his own, and practised it with success, as in his country, the community would have been benefited; on the other hand he would have seen, had it failed, that the climate of France was not proper for such experiments. M. Maillet, consul at Cairo, to whom Monsieur the regent had written to obtain the art, offered to send over a native of Egypt, if the government would pay the expense of his voyage, and allow him a pension of 1500 livres. M. Maillet rightly judged, when he preferred this method of proceeding. M. de Reaumur was not ignorant of the design; but he flattered himself, that his efforts would be successful without further aid, and thought he should acquire some honour. He certainly had great talents, industry, sagacity, and every other requisite which are necessary in such attempts; but it is morally impossible that a single man, in a different climate, can attain such knowledge in an art as those who live in a more favourable country, and have had the experience of many ages to profit by: however M. de Reaumur may have been unsuccessful, posterity is indebted to him for his repeated trials. He has removed some difficulties in the road, and those that travel it may discover what he only saw at a distance.

REAUMURIÁ, a genus of plants belonging to the pentandria clas; and in the natural method ranking under the 13th order, Succulentae. See Botany Index.