On the Basalt es of Saxony. 65 



yards and the height about fifty. This basaltes is divided 

 into prisms, most of them dismembered. It is of a grayish 

 black colour, very hard, and contains a large quantity of 

 olivin, which, being rapidly decomposed on the surfaces 

 exposed to the air, leaves a multitude of irregular or angular 

 cavities. This basaltes contains also some grains of carbo- 

 nated lime. 



10th, The Luchauerherg has the form of a cone, almost 

 insulated on every side, and terminating in a basaltic sum-- 

 mit about fifty yards in height. The body of the mountain 

 is gneiss covered by porphyry. The basaltes is of the same 

 nature as the preceding; but it contains only few grains of 

 olivin and amphibolite. At the summit of the cone is a small 

 cavity or depression two yards in depth. 



11th, The Heulenberg, situated near the frontiers of Bo- 

 hemia, consists of gres, of which almost the whole region 

 around is composed. The basaltic summit consists of two 

 groups of prisms, very regular. The basaltes is black, and 

 exceedingly compact. It contains a great many grains of 

 magnetic iron ore, and a mineral which has a close relation 

 to the pyroxen (augite of Werner), and which is found 

 here in considerable quantity. 



12th, The Stolpen is the most remarkable of all the ba- 

 saltic mountains of Saxony, on account of the beauty and 

 regularity of the basaltes. The body of the mountain is of 

 granite. C. Daubuisson does not venture tO'assert that the 

 basaltes rests immediately upon it ; he observed on the gra- 

 nite a sort of wacke, which, perhaps, is extended between 

 both. The basaltic summit appeared to him a kind of in-* 

 verted cone, the point of which is sunk into a depression 

 which existed in the top of the mountain when these mat- 

 ters were deposited. This basaltes is an assemblage of 

 beautiful prisms, most of them regular hexagons, standing 

 in a position almost vertical, and traversed by horizontal 

 and parallel fissures which divide them into stories. They 

 are of a black colour, \Vith a blueish tint. They are so- 

 norous, and as hard as iron. Small round cavities, the sides 

 of which are covered with a stratum of chalcedony, lined 

 itself with crystals of quartz, or filled with green steatites, 

 are often remarked in them. At other times these cavities 

 contain balls of calcareous spar, zeolite, and lithomarga, 

 having the appearance of semi-opal. This basaltes contains 

 besides, small grains of olivin and black shining points of 

 amphibolite, — if it be not, perhaps, the substance mentioned 

 in the preceding article. 



After having thus described the principal basaltic sum- 

 Mo. 73. June 1804. E mits 



