Jean-Etienne, a learned mathematician, was the son of a merchant, and was born at Lyons in 1725. He attended the college of the Jesuits in his native city, and was early distinguished by his tenacious memory and his aptitude for mathematics. At the age of sixteen he removed to Toulouse to prosecute the study of law; and after taking the usual degrees he repaired to Paris. There his conversational powers, his solid information, and his acquirements as a linguist, soon introduced him to the notice of the learned. In the society of D'Alembert and Lalande, his taste for mathematical studies was confirmed and stimulated. After publishing two anonymous treatises on the Quadrature of the Circle, and the Duplication of the Cube, he gave to the world in 1758 the first part of his great work, The History of Mathematics. Not long after this his merits were recognised by the French government, and he was promoted to several important offices. He was appointed intendant-secretary at Grenoble in 1758, secretary to the expedition for colonizing Cayenne in 1764, and premier commissaire des bâtiments, and censor-royal for mathematical books, in 1765. During the next twenty-five years his time was divided between his official duties and the study of his favourite science. The Revolution then ensuing, deprived him of his income, and left him in great destitution. The offer in 1795 of a mathematical chair in one of the schools of Paris was declined on account of his infirm health, and he was still in straitened circumstances in 1798, when he published a second edition of the first part of his History. He also enlarged Ozanam's Mathematical Recreations, afterwards published in English by Dr Hutton, 4 vols., Lond. 1803. About four months before his death a pension of 2400 francs was conferred upon him. He died in December 1799. His History of Mathematics was completed by Lalande, and published in 4 vols. 4to, 1799-1802.