KNAPP, Mathias, German explorer, born in Werden in 1752; died in Fulda, Hesse-Cassel, in 1814. He was educated in Munich, appointed in 1776 professor of natural history in the College of Erlangen, and was called to fill the same chair at the University of Munich in 1782. In the following year he was chosen president of the scientific expedition that was sent to South America by the Duke of Bavaria. He made a thorough survey of the Andes, visited Brazil in its most remote parts, resided in Venezuela in 1787-'9, studying the ethnography of that country, and afterward visited the Guianas, Peru, Chili, the Andes, Patagonia, and the Argentine Republic. He returned in 1792, and, resigning his professorship, devoted his time to the publication of the materials he had collected during his ten years' travels through South America. He afterward removed to Fulda, where he resided till his death. Among his works are "Origines gentis Americanorum " (Munich, 1795); "De usu et ratione experimentorum in perficienda historia naturalis" (Dresden, 1796); " Versuch fiber die Zeitrechnung der Vorwelt" (Leipsic, 1796);"Reisen im Sudwesten yon Brazilien "(2 vols., 1797); "Geschichte der Entdeckung Amerikas" (3 vols., 1798); "Reisen nach Amerika" (3 vols., 1801); "Guianische Skizzen" (Dresden, 1804); "Reise dutch Peru und Chile" (2 vols., Leipsic, 1805); and "Die Chemic und ihre Anwendung auf das praktische Leben" (Dresden, 1808).