Page:Quarterly Journal of the Geological Society of London, vol. 25.djvu/434

 the very general belief that it was richly auriferous. Two large parties of miners did indeed forcibly enter the ground, but found so little as to discourage their return at the risk of violating the law. By the kindness of His Grace the Duke of Portland I was enabled to make a careful examination of all the rocks in the Langwell and Berriedale valleys, traversing the mountains, and examining every rocky stream ; and so far as such search is conclusive, apart from washing for gold, I should be inclined to think that this district is less likely to prove auriferous than that on the Sutherland side of the ridge between Cnock-nan-Eirinneach and Suidhe-'n-fhir-bhig, the line of the county march.

This opinion is of course solely founded upon the apparent absence of those rocks which seem to be associated with the richest deposits in the district of Kil-Donnan.

5. The source of the gold, however, is still undiscovered, since nowhere has it yet been found in rock in situ. Several specimens of water-rolled stone, rich in gold, have been found in Suisgill and Kil-Donnan burns : these, with the specimen already referred to, are now exhibited; and it will be seen that in every instance the components of the stone are felspar and quartz, with one exception, in which the rock is quartz only, but not such a large fragment as may not have belonged to the quartzo-felspathic rock c. Arguing from the comparative poverty of the drift where this rock or its detritus is scarce, and connecting its prevalence in Suisgill and Kil-Donnan with the rich alluvium there, we may venture, I think, to infer from these facts and those rock-specimens that the granitiform rock c may yet be found to be the matrix of the gold.