108 



MINERALOGICAL NOTICES 



as In vera we, where it appears in the neighbourhood 

 of granite, as at Balahulish, and other places in this 

 district of Scotland. Higher up the side of the 

 mountain, the clay-slate passes into a species of 

 very quartzose and compact mica-slate, containing 

 beds of greenstone, and veins of felspar mixed with 

 hornblende. Above this, common felspar, and por- 

 phyry, with base of felspar, sometimes approaching 

 to hornstone, and decomposed in masses of various 

 shapes, chiefly tabular and rectangular parallelopi- 

 peds, occupies a great extent of surface, and forms 

 some of the highest points. The specimens of gra- 

 nite, collected towards the summit of Cruachan^ 

 present considerable varieties of character. Some- 

 times the ingredients appear mixed in the usual 

 proportion. In other places, the crystals of quartz 

 and felspar are found imbedded in common felspar, 

 with little mica ; — thus passing into porphyry. Fel- 

 spar, indeed, as already remarked, is, in general, at 

 this elevation, the prevailing substance of the rocks. 

 And the compact species, tinged with hornblende, 

 appears in the same geognostic relations as. it does 

 in the upper part of Ben Nevis. 



Buna we.— On the west side of Cruachan, the 

 granite and quartzy mica-slate descend to the level 

 of the sea, and are found accompanied with a varie- 

 ty of different rocks, at the sides of Loch Etive, 

 and around Bunawe. In this direction, I observed 

 the following substances ; syenite, quartz, greenstone, 

 serpentine, quartzy felspar, felspar coloured with 



