by Professor Studer, 169 



indeed, there are really alpine mountains, such as do not 

 often appear under the Scottish heaths : one might imagine 

 himself in the Valley of the Albula, or in Val Vedro on the 

 Simplon ; and Kingshouse, standing solitary on the water- 

 shed, although scarcely 1000 feet above the sea, reminds the 

 traveller from Switzerland of one of our mountain passes. 

 This region is the principal scene of Ossian's poetry ; and in 

 summer it is resorted to by an almost uninterrupted succes- 

 sion of English tourists. Numerous red and white granites, 

 syenites, and porphyries, here occur in close connexion ; and, 

 with the exception, perhaps, of Sassa, it would be difficult to 

 find any region so well adapted for a very remunerating study 

 of the questions which yet remain unsettled respecting these 

 rocks and their mutual relations. Great dikes of red felspar- 

 porphyry ascend vertically on both sides of the glen to the 

 summits of the hills, and appear there to spread out over the 

 chlorite slates which they intersect. Higher up the valley, 

 the rock surrounding the red porphyry is of a black and red- 

 dish-brown colour, and resembles flinty-slate or jasper, but 

 is still more similar to the black porphyries of the Lake of 

 Lugano, and, like these, it contains nests and small veins of 

 epidote, and small separate twin crystals of a kind of felspar, 

 perhaps albite. Thfe dense substance of the rock is with dif- 

 ficulty melted into a white glass. The rock is split vertically 

 into plates, some of which are of small thickness, but it also 

 shews traces of horizontal division ; thus agreeing with the 

 chlorite-slate situated lower in the valley, and with the 

 gneiss at Kingshouse. It may perhaps be, not an eruptive 

 rock, but a sedimentary one, altered in its present place and 

 position by the red porphyry, as is assumed by Fournet to 

 be the case with similar kinds of rock in South Tyrol. We 

 are naturally led to compare, with the black rock and the red 

 porphyry of Glcncoe, the similarly-coloured rocks which form 

 the mass of Ben-Nevis. The black porphyry of this highest 

 peak of the Scottish mountains, is richer in felspar than that 

 of Glencoe. I have not observed epidote in it. The division 

 into plates, and the tendency 1o the character of jasper, are 

 wanting ; yet identical modifications might easily be obtained 

 from both places ; and the rock of Ben-Nevis exhibits the 



