INTRODUCTION. 63 



interest had been roused throughout Europe by the results of 

 Von Humboldt's brilliant volcanic studies in Central and 

 South America, and Von Buch determined to make a special 

 study of some volcanic district. 



Accompanied by the English botanist, Charles Smith, he 

 visited the Canary Isles, and in 1815 convinced himself that 

 they had been the centre of intense volcanic activity. In his 

 famous monograph, A Physical Description of the Canary 

 Islands, published in 1825, he enunciated his hypothesis of 

 upheaval craters, and distinguished between "centres" and 

 " bands" of volcanic action. In 1817 he travelled to Scotland 

 and visited Staffa and the Giant's Causeway. When he again 

 returned to the Alps, he renounced the Wernerian doctrines of 

 the origin of basalt and other volcanic rocks, and ascribed the 

 upheaval of the Alps to the intrusion of igneous rocks. About 

 this time he went to Fassa Valley in South Tyrol, and there he 

 formed a curious volcanic theory in explanation of the dolo- 

 mitisation of the rocks in that district. 



In 1832 Von Buch edited a geological map of Germany, and 

 this magnificent work had already run through five editions in 

 1843. The last twenty years of his life were for the most part 

 devoted to palaeontological studies, and we owe to this period 

 a valuable series of papers on Cephalopods, Brachiopods, 

 and Cystoids; also a comprehensive treatise on the Jurassic 

 formation in Germany, which has been the basis for all 

 future work on this subject. Some part of every year, 

 however, was spent by Von Buch in travelling. He often 

 went to the Alps, and he regularly attended the Scientific 

 Congresses. Most of his Alpine journeys were accomplished 

 on foot. Clad in short breeches, black stockings, and buckled 

 shoes, the pockets of his black coat stuffed with note-books, 

 maps, and geological tools, his tall, imposing figure was bound 

 to command attention. His travelling luggage was limited to 

 a fresh shirt and a pair of silk stockings. His physical en- 

 durance was only surpassed by his iron determination, which 

 could overcome all difficulties and discomforts. Socially, he 

 was everywhere beloved; his aristocratic bearing, his mastery 

 of foreign languages, his wide knowledge of science and 

 literature, all combined to make him one of the most agree- 

 able companions. His independent means placed him in a 

 position of unusual influence. On the one side he enjoyed 

 the friendship and intimacy of his scientific colleagues, and on 



