Montmort, Peter Raymond De

, an able mathematician, was born at Paris in the year 1678, and intended for the profession of the law, to enable him to qualify for a place in the magistracy. From dislike of this destination, he withdrew into England, whence he passed over into the Low Countries, and travelled into Germany, where he resided with a near relation, M. Chambois, the plenipotentiary of France at the diet of Ratisbon. He returned to | France in 1699, and after the death of his father, who left him an ample fortune, devoted his talents to the study of philosophy and the mathematics, under the direction of the celebrated Malehranche, to whom he had, some years before, felt greatly indebted for the conviction of the truth of Christianity, by perusing his work on “The Search after Truth.” In 1700 he went a second time to England, and on his return, assumed the ecclesiastical habit, and was made a canon in the church of Notre-Dame, at Paris. About this time he edited, at his own expence, the works of M. Guisnee on “The Application of Algebra to Geometry,” and that of Newton on the “Quadrature of Curves.” In 1703 he published his “Analytical Essay on Games of Chance,” and an improved edition in 1714. This was most favourably received by men of science in all countries. In 1715 he paid a third visit to England, for the purpose of observing a solar eclipse, and was elected a fellow of the Royal Society, to which learned body he soon afterwards transmitted an important treatise on “Infinite Series,'” which was inserted in the Philosophical Transactions for the year 1717. He was elected an associate of the Royal Academy of Sciences at Paris in 1716, and died at the early age of forty-one, of the small-pox. He sustained all the relations of Hie in the most honourable manner, and though subject to fits’ of passion, yet his anger soon subsided, and he was ever ashamed of the irritability of his temper. Such was his steady attention that he could resolve the most difficult problems in company, and among the noise of playful children. He was employed several years in writing “A History of Geometry,” but he did not live to complete it. 1