Lelong, Jacques an eminent French bibliographer, was born at Paris April 19,1665. In 1677 he was sent by his father to Malta, to be educated as a member of the order of Knights, but not liking the severity with which he was treated, he obtained permission to return to Paris. Here he continued his studies, and, as he had not yet taken the vows of the Order of St. John of Malta, he entered the Congregation of the Oratory in 1686. He became successively professor of mathematics in the College of Juilli, and afterwards in the seminary of Notre Dame des Vertus, near Paris. Later he was appointed librarian of that institution, and in 1699 was transferred in the same capacity to the library of the Oratoire St. Honore, at Paris, one of the richest in that city, especially in Oriental books and MSS. This position he occupied for twenty-two years, rendering the greatest services to the scientific world by his valuable bibliographical researches, and by a threefold catalogue. He died Aug. 17, 1721. His most important work, which is yet highly prized by students, is his Bibliotheca Sacra (Par. 1709, 2 vols. 8vo; 2d ed. 1723, 2 vols. fol. — this latter ed. is by far the best). Another augmented edition was published after his death by Desmolets, a priest of the Oratory (Paris, 1723, 2 vols. fol.). A valuable supplement was afterwards added to it, and the whole work carefully revised, by Chr. Fr. Borner (Lips. 1709); another enlarged and extended edition was published by A. G. Mlasch (Halle, 1778-1790, 5 vols. 4to). As a historian, Lelong distinguished himself particularly by his Bibliotheque historique de la France, contenuant le catalogue des outrages imprimis et manuscrits, qui traitent de l'histoire lde ce royaume (Par. 1719; 2d ed. by Fevret de Fontette, Par. 1768, 5 vols. fol.). This was to have been followed by notices on the author of these works. Lelong wrote Discours historiques sur les principales editions des Bibles Polyglottes (Paris, 1713): — Supplement as l'histoire des dictionnaires Habreux de Wolfus (Par. 1707): —Nouvelle methode des langues Hebraique et Chaldaique (Par. 1708), etc. See Desmolets, Vie du P. Lelong, in the 2d and 3d edition of the Bibliotheca Sacra; Herzog, Real-Encyklopadie, 8:290: Hoefer, Noeuv. Biog. Generale, 30:540 sq., Kitto, Bibl. Cyclop. s.v.