170 Proceedings of the Royal Physical Society. 
rocks. Up the lake, a little beyond the mouth of the Awe, 
a felspar porphyry is seen under the granite, into which it 
appears to pass. This porphyry show^s divisional planes 
ranging N. 30° W. At the bend of the loch, about two 
miles above Bunawe, the divisional planes of the granite are 
vertical, with a N.E. by N. strike, directed exactly to the 
valley between the Buachaile Etive mountains. This tract 
is one of the most instructive in Scotland in relation to the 
present subject. 
5. Arran. — In ascending Goatfell from Brodick, at the 
mill-dam, where the junction of the granite and schists 
occurs, the latter are very hard and quartzose, commonly of 
a greenish grey colour, but sometimes dark, and resembling 
certain carboniferous shales. The granite sends veins into 
the schists, some of them only two inches wide. The sub- 
stance of these veins is fine-grained, chiefly felspathic, and 
is firmly welded to the schists, though the line of demarca- 
tion is most distinct. The granites of Goatfell, Glen Eosa, 
Caistael Abhael, and of Arran generally, are chiefly composed 
of felspar, the quartz being in considerably smaller quantity, 
and the mica very deficient. In Glen Eis-na-bearadh, be- 
tween two and three miles from Loch Kanza, a dyke of fine- 
grained granite appears in the bed of the stream. Further 
down, this dyke is seen to be connected with a mass of 
the same character, underlying the ordinary large-grained 
variety, and penetrating it in veins. The fine-grained 
granite is in some places almost wholly felspathic. Near 
the foot of the glen the junction of the granite with chloritic 
schists is well seen, the latter dipping under the former at 
angles of about 60°. The schists constitute the bulk of the 
conspicuous hill called Toirnaneidnoin, on the west side of 
which, at a great height, they are seen to be penetrated by 
granitic veins. Near the junction the schists are very hard, 
and shew alternating dark and light coloured laminae, gener- 
ally even, but sometimes curiously contorted. At the junc- 
tion of the glen with Glen Chalmadail, the schists are verti- 
cal, with a W.N.W. to E.N.E. strike. 
6. Portsoy. — A short way east of the town (upon the 
shore) the schistose rocks are nearly vertical, and consist 
