REAUMUR (Rene - Antoine - Ferchault, Sieur de)

, a respectable French philosopher, was born at Rochelle in 1683. After the usual course of school education, he was sent to Poitiers to study philosophy, and, in 1699, to Bourges to study the law, the profession for which he was intended. But philosophy and mathematics having very early been his favourite pursuits, he quitted the law, and repaired to Paris in 1703, to pursue those sciences to the best advantage; and here his character procured him a seat in the Academy in the year 1708; which he held till the time of his death, which happened the 18th of November 1757, at 74 years of age.

Reaumur soon justified the choice that was made of him by the Academy. He made innumerable observations, and wrote a great multitude of pieces upon the various branches of natural philosophy. His History of Insects, in 6 vols. quarto, at Paris, is his principal work. Another edition was printed in Holland, in 12 vols. 12mo. He made also great and useful discoveries concerning iron; shewing how to change common wrought iron into steel, how to soften cast iron, and to make works in cast iron as fine as in wrought iron. His labours and discoveries concerning iron were rewarded by the duke of Orleans, regent of the kingdom, by a pension of 12 thousand livres, equal to about 500l. Sterling; which however he would not accept but on condition of its being put under the name of the Academy, who might enjoy it after his death. It was owing to Reaumur's endeavours that there were established in France manufactures of tin plates, of porcelain in imitation of china-ware, &c. They owe to him also a new thermometer, which bears his name, and is pretty generally used on the continent, while that of Fahrenheit is used in England, and some few other places. Reaumur's thermometer is a spirit one, having the freezing point at 0, and the boiling point at 80.

Reaumur is esteemed as an exact and clear writer; and there is an elegance in his style and manner, which is not commonly found among those who have made only the sciences their study. He is represented also as a man of a most amiable disposition, and with qualities to make him beloved as well as admired. He left a great variety of papers and natural curiosities, which he bequeathed to the Academy of Sciences.

The works published by him, are the following.

1. The Art of changing Forged Iron into Steel; of Softening Cast Iron; and of making works of Cast Iron, as fine as of Wrought Iron. Paris, 1722, 1 vol. in 4to.

2. Natural History of Insects, 6 vols. in 4to.

His memoirs printed in the volumes of the Academy of Sciences, are very numerous, amounting to upwards of a hundred, and on various subjects, from the year 1708 to 1763, several papers in almost every volume.