on the Mountain Cruachan. 123 



A similar greyish basis with dispersed crystals of hornblende 

 only. 



A basis of hornblende with distinct crystals of felspar ; of a 

 porphyritic character. 



An uniform mixture of hornblende and felspar, approaching to 

 common greenstone, and at length not to be distinguished from it. 



These latter varieties appear to form a regular series of a transition 

 from porphyry to trap, of which I shall immediately speak ; first 

 remarking that besides these leading varieties which I have 

 now described, there are many others which it would be super- 

 fluous to notice, as the variations of colour, aspect, and composition, 

 are endless. Together with the veins of decided porphyry, various 

 parts of the mountain are intersected by veins of grey rock, having 

 as I have just remarked, the general character of the trap rocks, and 

 sometimes porphyritic. Veins of perfectly characterized basalt also 

 occur in some places, and these, or fragments of them may in par- 

 ticular be observed in great quantity strewing the top of the first 

 summit, (that one which is marked by two cairns,) and laying fair 

 claim to an equal antiquity with the veins of porphyry. It is easy 

 to procure detached specimens of the junction between the granite 

 and basalt in great variety and abundance. The line of junction is 

 in all cases clear and well defined, but does not admit of ready sepa- 

 ration even after long exposure to weather. My observations on 

 the base of the hill were terminated here, some way before the 

 place where the foot of Ben Starive interferes with that of Cruachan. 



I have already said that in ascending Cruachan the schist soon 

 disappears : at the same time the accumulation of soil and the cover- 

 ing of plants are so great, that it is scarcely possible to meet with 

 the natural rock for at least half the ascent. Many masses which 



