(Lewis Ferdinand, count), an Italian famous for letters as well as arms, was descended from an ancient and noble family, and born at Bologna in 1688. He acquired a great knowledge in the art of war and fortification; served under the emperor Leopold II. against the Turks, by whom he was taken prisoner in 1683 but redeemed, after a year's captivity. In the Spanish succession war, Marsigli then advanced to the rank of marshal, being in the fortress of Brisac, which surrendered to the duke of Burgundy in 1703, when the place was deemed capable of holding out much longer, was stripped of all his commissions, and had his sword broken over him; and the count d'Arco who commanded was beheaded. Marsigli now sought for consolation in the sciences; as, amidst all the hurry and fatigue of war, he had made all the advantages the most philosophic man could do, who had travelled purely in quest of knowledge. He had a rich collection of every thing proper to the advancement of natural knowledge, instruments astronomical and chemical, plans of fortifications, models of machines, &c., all which he presented to the senate of Bologna by an authentic act in 1712, forming at the same time out of them what he called the institute of the arts and sciences at Bologna. He also founded a printing-house, and furnished it with the best types for Latin, Greek, Hebrew, and Arabic, which he presented in 1728 to the Dominicans at Bologna, on condition of their printing all the writings of the institute at prime cost; this was called the printing-house of St Thomas Aquinas. His writings on philosophical subjects are numerous and valuable, in Latin, Italian, and French; he died in 1730.