1 88 HISTORY OF GEOLOGY AND PALEONTOLOGY. 



Greek Archipelago, in the Adriatic and Tyrrhenian Seas, on 

 the north coast of the Mediterranean Sea, and on the shores of 

 the Atlantic Ocean, the North and Baltic Seas. 



The second volume treats of volcanoes, earthquakes, and 

 geysers. The author brings forward no new hypothesis about 

 the causes of these phenomena, but follows largely the 

 views of Von Humboldt and Von Buch. The chief merit 

 of Von Hoff is his careful epitome of all reliable informa- 

 tion regarding the changes and disturbances which have 

 been produced by volcanoes and earthquakes within historic 

 time. 



Ten years elapsed between the appearance of the second and 

 the third volume of Von Hoff's work. During the interval 

 the first volume of Charles LyelPs Principles of Geology was 

 published, and its influence upon Von Hoff is quite apparent 

 in the third volume of his work. In this third volume, Von 

 Hoff discusses the causes of the degradation of land. The 

 changes in surface conformation and the gradual destruction 

 of a continent are referred to atmospheric agencies, to the 

 chemical and mechanical action of water, snow, and ice, to 

 living organisms, and to the erosive action and usurpations 

 of the sea over coastal territories. He discredits Buckland's 

 hypothesis of a universal flood in a learned and convincing 

 chapter. 



The meritorious work of Von Hoff did not meet with the 

 full recognition which it deserved. This arose largely from 

 the fact that Von Hoff drew his data almost wholly from 

 literature, his modest circumstances not permitting him to 

 visit the localities of which he wrote; his conclusions were 

 therefore based upon historical evidence. 



In France, Constant Prevost, quite independently of Von 

 Hoff's work, attacked the catastrophal theory of Cuvier. In 

 1825, Prevost announced his view that the physical conditions 

 and phenomena of the present age were in every respect similar 

 to those which had characterised the past geological epochs. 

 In 1828, he repeated this opinion, and protested against 

 the frequent inundations by the sea assumed by Cuvier and 

 Brongniart to have taken place in the Paris basin. Prevost's 

 attack upon Cuvier's theory had little effect, as it was not 

 supported by any new data, and he weakened his arguments 

 by allowing that certain geological forces might have developed 

 stronger energies in past epochs than in the present. 



