Mountains of Hesse, SfC. 105 



of the mass ; and lastly the basaltic mass, full of irregularly- 

 disseminated clefts. This basalt contains much olivine, 

 hornblende, and felspar; it also contains fragments of sand- 

 stone, but neither variolites or lavas have been observed in 

 it. As these relations of position to the sandstone are only 

 made known by this gallery, it might be said that the basalt 

 is here a vein in the sandstone ; but M. de Hoff observes 

 that every thing leads us to the belief, judging at least from 

 analogy, that this position is of the same nature as those 

 before noticed. 



* The basaltic rocks mentioned in this paper are evidently the same 

 as the basaltic and other trap dykes of the British islands. A very in- 

 teresting and detailed account of the trap dykes of Anglesea by Mr. 

 Henslow, occurs in the 1st volume of the Cambridge Philosophical 

 Transactions, page 401, &c. ; and those of the Hebrides, &c. will be 

 found ably discussed by Dr. Mac CuUoch in his account of the Western 

 Islands, and in the Geological Transactions, which also contain many 

 other descriptions of similar facts. (Trans.) 



