Prosper, a learned bibliographer, born in 1675, at Guise, in Picardy, studied at Paris with much success, and having from his infancy been passionately devoted to books, he was admitted in 1698 into the corporation of booksellers. An eager collector of literary anecdotes, he transmitted them to Jacques Bernard, who then conducted in Holland the Nouvelles de la République des Lettres. In 1711 Marchand passed into Holland, that he might be more free to profess the Reformed religion, which he had embraced. He established himself at Amsterdam, and there continued for some time the business of bookselling, but ultimately abandoned it altogether, in order to devote himself exclusively to study. He died on the 14th of June 1756, and left his rich library to the University of Leyden. In addition to his extensive annotations, &c., Marchand's principal works are,—Histoire de l'Origine et des premiers Progrès de l'Imprimerie, Hague, 1740, in 4to; Dictionnaire Historique, or Critical and Literary Memoirs of different distinguished persons, particularly in the republic of letters, Hague, 1758, 1759, two volumes folio.