DOMAIN II. SILICBOT7S. 



classed with the trap-mountains*. In Germany 

 it occurs chiefly in the middle mountains of Bohe- 

 mia, in Upper Lusatia, and in the district of Ful- 

 da. It does not form coherent ranges of moun- 

 tains, but always only detached masses of rocks 

 and insulated mountains, commonly on the side 

 of similar basaltic mountains. It belongs to the 

 most durable sax a, and resists the withering in an 

 eminent degree. Only on its surface some decay 

 takes place, by which it acquires a pale clayey 

 crust, -the smoothness of which renders the ascen- 

 sion on klingstone-porphyry mountains somewhat 

 unsafe. Some of these mountains, though but 

 sparingly covered with fertile soil, are nevertheless 

 well invested with plants and forest-trees ; as for 

 instance the Donnersberg, near Milleschau, and 

 the Schlossberg, near Toplitz. But most fre- 

 quently the klingstone-porphyry occurs in the 

 shape of cliffs, which are dentated in a grotesque 

 manner, from the unequal, mostly vertical, se- 



* In the German trapp formation. This expression is now, 

 according to Emmerling, by the latest German mineralogists used 

 to signify all mountains constituted of grxinstein, amygdaloid, schis- 

 tose-porphyry, basaltes, and their subordinate species. All these 

 are called trapp-gelirge, since those saxa not only occur in moun- 

 tains of the same kind, but also very much agree in their geo- 

 gnostic relations ; so that evidently they are of the same formation. 

 Transl. 



