BUCH, CHRISTIAN LEOPOLD VON, BARON (1774 18S3), German geologist and geographer, a member of an ancient and noble Prussian family, was born at Stolpe in Pomerania on April 26 1774. In 1790-93 he studied at the mining school of Freiberg under Werner, one of his fellow-students there being Alexander von Humboldt. He completed his education at the universities of Halle and Gottingen. In 1797 he met Humboldt at Salzburg, and with him explored the geological formations of Styria and the adjoining Alps. A visit to Italy in 1798 shook his faith in the Neptunian theory. In 1799 he paid his first visit to Vesuvius, and again in 1805 he returned to study the volcano, accompanied by Humboldt and Gay Lussac, when they witnessed an eruption which supplied von Buch with data for refuting many erroneous ideas then entertained regarding volcanoes. In 18o2 he had explored the extinct volcanoes of Auvergne. The scientific results of his investigations he embodied in his Geog nostische Beobachtungen auf Reisen durch Deutschland and Italien (Berlin, 1802-09). Von Buch spent two years among the Scandinavian islands ; he showed that many of the erratic blocks on the North German plains must have come from Scandinavia. He also established the fact that the whole of Sweden is slowly but continuously rising above the level of the sea from Fred erikshald to Abo. The details of these discoveries are given in his Reise durch Norwegen and Lappland (Berlin, 181o). In 1815 he visited the Canary islands in company with Christian Smith, the Norwegian botanist. The physical description of the Canary islands was published at Berlin in 1825. After leaving the Canaries, von Buch proceeded to the Hebrides and the coasts of Scotland and Ireland. He published in 1832 the magnificent Geological Map of Germany (42 sheets, Berlin). His geological excursions were continued without interruption till his 78th year. He died at Berlin on March 4, 1853. Humboldt pronounced him the greatest geologist of his time.
A complete edition of his works was published at Berlin (1867-85), edited by Ewald and others.