ISELIN, Jacob Christian (e'-ze-leen), Swiss explorer, born in Basle in 1753; died in Freiburg in 1811. He studied in Geneva, and was professor of history in the University of Basle, when, in 1785, he inherited a large estate from an uncle, and resolved to explore the New World, He visited the Canary islands, Brazil, Chili, Peru, the Marquesas islands, Pomata, and Tahiti, and afterward went by land from California to Texas, descended thence to Mexico and via the isthmus of Panama to South America, where he remained altogether twenty-two years. He returned in 1806 to Europe with a large number of documents, maps, and notes, which he deposited in the public library of his native town, and devoted the remainder of his life to researches among the public libraries of Europe, thus gathering a huge collection of original documents on America. He published "Analecta Peruviana seu genera et species plantarum in Peruvia erescentium" (2 vols., Geneva, 1808); "Monografia de las votes eompuestas de Chile" (2 vols., Basle, 1809); "Ascencion du Pichincha et Chimborazo" (Geneva, 1810); "Du mouvement religieuse dans l'Amerique du Sud" (Basle, 1809); "Histoire de la conquete et de la domination Espagnole dans l'Amerique du Sud," which was for a long time a standard work on the conquests and explorations of European adventurers (6 vols., Basle, 1811, with charts).