126 Dr. Mac Culloch's observations 



region, which, in addition to its extent and difficulty, is nearly void 

 of inhabitants. "Whether it be well founded or not, the rocks which 

 form this mountain can be traced, under certain modifications, beyond 

 the boundary here mentioned, and as they add useful illustrations 

 to the subject, while they also serve the purpose of determining a 

 difficult tract in the geological topography of Scotland, I shall make 

 no apology for describing them. 



Granite is found at Balahulish, extending round the shore oF 

 Loch Leven on its southern side towards Appin, assuming during 

 this course, various aspects ; but it is generally grey and small 

 grained, and of the most ordinary appearance and composition, 

 consisting of quartz, mica, and felspar. Superadded to these, it 

 frequently contains hornblende, or else it consists of quartz, felspar, 

 and hornblende, a circumstance which as I have before remarked 

 forms no distinction geologically considered. 



It appears here to be the basis on which micaceous schistus and 

 quartz rock repose, both of which conjoined form the group of 

 mountains called Ben na vear, which rises above the house of 

 Balahulish. It is not necessary for the purpose I have now in view 

 to inquire into the further extent of these rocks. Branches of the 

 same granite in no way altered in character pass through the schist, 

 and probably the quartz rock, although I did not detect their actual 

 junction with this last. I can only conclude that as the schist and 

 quartz rock alternate, that vein which traverses the one must also 

 traverses the other. The schist which is traversed by the granite 

 often much indurated, and approaches by various undefinable gra- 

 dations to a sort of hornblende slate. Masses of a similar substance 

 may be found imbedded in many parts of the granite. Occasion- 

 ally these masses appear on close examination to be only irregular 

 spots of hornblende, such as occur not unfrequently in those gra- 



