INGENHOUS, Jean Simon (ing-en-hows), Dutch explorer, born in Maestrich in 1701; died in Rotterdam in 1769. His father was a famous surgeon, and the son was also graduated in surgery, obtaining an appointment in 1723 on a ship that belonged to the Indian company. On returning to Amsterdam the vessel foundered at sea, and the crew, after several days of suffering in an open boat, was rescued by a passing Spanish man-of-war that was bound for Buenos Ayres. In that city Ingenhous was taken sick with fever and brought to the hospital of the Jesuits, who saw at once the opportunity of attaching to their order a physician of repute. They nursed him with the best care, and when he was convalescent took him to a villa in the country. Ingenhous at last succumbed to their suggestions, and having abjured the Reformed church in 1725, became a Jesuit in 1728. In the following years he was attached to the missions of the Par£ and resided several years on the borders of the river Tocantin. In 1742 he was elected provincial of the Uruguay missions, and greatly benefited the condition of the Indians in those countries, altogether increasing the influence of the order. But he had retained doubts regarding his change of religion, and, on the expulsion of the Jesuits from South America in 1767, returned to Amsterdam, where he abjured the Roman Catholic faith and was appointed librarian of the museum of Rotterdam. He held that office till his death, and published "de la naturaleza y virtudes de los arboles, plantas y animales de la America, de que se aprovecha la medicina" (Rotterdam, 1761); "Return medicinalium Novi Orbis thesaurus" (3 vols., 1763); "Lehrbuch der amerikanischen Geographic" (1764); and "I'description geographique et statistique des missions des Jesuites du Para et de l'Uruguay" (1765).