ABRAHAM DE, a very learned mathematician, was born in the year 1667, at Vitry in Champagne, in France, where his father was a surgeon. After the revocation of the edict of Nantes, he proceeded to England. Before he left France, he had commenced the study of the mathematics; and having perfected himself in that science in London, he was obliged, by necessity, to teach it. But Newton's Principia, which accidentally fell into his hands, showed him how little progress he had made in a science of which he thought himself master. From this work he acquired a knowledge of the geometry of infinites with as great facility as he had learned the elementary geometry; and in a short time he was enabled to rank with the most celebrated mathematicians. His success in these studies procured him a seat in the Royal Society of London, and in the Academy of Sciences at Paris. His merit was so well understood in the former, that he was thought capable of deciding in the famous dispute between Leibnitz and Newton concerning the differential calculus. He published a Treatise on the Doctrine of Chances in 1738, and another on Annuities in 1752, both extremely accurate. The Philosophical Transactions contain many interesting memoirs of his composition. Some of these treat of the method of fluxions; others of the lunula of Hippocrates; others of physical astronomy, in which he resolved many important problems; and others of the analysis of games of chance, in which he followed a different course from that of Montmort. Towards the close of his life he lost both his sight and his hearing; and the demand for sleep became so great that he required twenty hours of it in a day. He died at London in 1754, aged eighty-seven. His knowledge was not confined to the mathematics; and he retained to the last a taste for polite literature. He was intimately acquainted with the best authors of antiquity, and was frequently consulted about difficult passages in their works. Rabelais and Molière were his favourite French authors; indeed he had them by heart, and one day observed to an acquaintance, "that he would rather have been Molière than Newton." He recited whole scenes of the Misanthrope, with that delicacy and force with which he remembered to have heard them recited at Paris seventy years before, by Molière's own company. The character, indeed, was somewhat similar to his own. He judged severely of mankind, and could never conceal his disgust at the conversation of a fool, or his aversion to cunning and dissimulation. He was free from the affectation of science, and no one could have known that he was a mathematician except from the accuracy of his thoughts. His conversation was general and instructive. Whatever he said was well digested and clearly expressed. His style possessed more strength and solidity than ornament and animation; but he was always correct, and he bestowed as much pains on his sentences as on his calculations. He could never endure any bold assertions or indecent witticisms against religion.