268 HISTORY OF GEOLOGY AND PALEONTOLOGY. 



The extinct volcanoes of Central France, the Eifel and the 

 Siebengebirge, have been frequently mentioned in the fore- 

 going pages. Other favourite themes in geological literature 

 are the basalt and trachyte domes of the Westerwald, the 

 extensive volcanic district of the Vogelsgebirge, the extinct 

 volcanoes in the vicinity of Cassel, in the Habichts Forest, 

 Kaufung Forest, and the Meissner Mountain. As early as 

 1790, a mineralogical study of the Meissner was published by 

 J. Schaub, and a geological map of this mountain appeared 

 in 1817. 



The Rhon has a historical interest for geology, as it was the 

 basis of Voigt's attack on the Neptunistic doctrines of his 

 teacher Werner. The mode of occurrence of the phonolite 

 and basalt bosses in the Rhon convinced Voigt of their 

 volcanic origin. The first complete description of the Rhon 

 was given in 1866 by C. W. von Giimbel, in whose works on 

 Bavarian geology will be found all the important features of 

 the ancient centres of volcanicity in the Bavarian Forest. 

 Another district exhaustively treated by Giimbel is the 

 volcanic inthrow of the Ries. The basalt hills and tuff dykes 

 of the Swabian Alp have been examined by Quenstedt (1869), 

 Zirkel (1870), and more recently by W. Branco (1894). 

 Professor Branco contests the hypothesis that all volcanoes 

 occur upon tectonic fissures and faults. 



In the Hohgau in Baden phonolite and basalt mountains 

 rise to a height of nearly 3000 feet. They present for the 

 most part the characteristics of homogeneous volcanic rock, 

 but are partly accompanied also by masses of tuffs. The 

 pretty little volcanic mountain known as the Kaiserstuhl rises 

 from the Rhine Plain between the Black Forest and the Vosges 

 mountains. Baron von Dietrich in 1774 was the first to 

 recognise its volcanic origin. 



The basaltic bosses in Thuringia, Saxony, and Silesia, as well 

 as the extinct volcanoes in North Bohemia, Hungary, and 

 Transylvania, have been the subject of petrographical papers, 

 but have had no marked influence upon general conceptions of 

 volcanism. The Kammerbiihl near Eger has some historical 

 interest, and a new paper was published upon it by Prost 

 {Jahrbuch) 1894). 



The writings on the district of Predazzo and the neighbour 

 ing parts of the Fassa Valley and Schlern fill an important 

 page in the history of volcanism. In 1819 Count Marzari 



