Mineralogy of Sky. SS 



to the mica slate ; I imagine no error will be committed if I con- 

 sider it as a continuation of this series. 



This is the rock which forms the high mountains above the 

 Kyle ri*ch, which have already been mentioned in the general 

 description. The principal summits, on account of their elevation, 

 are visible at a considerable distance in coming from Glen Elg, and 

 they occupy the greater portion of that which may be called the 

 eastern promontory of Sky. Ben na Grien and Ben Ashlaig appear 

 to be the highest of the group : these decline into lower elevations^ 

 and with some variation both of character and aspect till they dis>- 

 appear, but I have to regret that I can give no account of the con- 

 nections of either of the outer extremities with the neighbouring 

 rocks. It is too common for the geologist in the course of his 

 labours to find that he has commenced at the wrong end of his in- 

 vestigation, and to discover, when it is too late to profit by it, that 

 he has probably found the solution of his previous difficulties when 

 the difficulties themselves are no longer accessible to him : I can 

 only therefore offer it as a conjecture, that the rock which forms 

 the mountains in question is a continuation of the one already de- 

 scribed at Loch Eishort, since its examination unfortunately pre- 

 ceded that of the latter, and it was out of my power to resume 

 it when I had obtained the information which would probably have 

 enabled me to speak decisively concerning it. I would recommend 

 to those who may follow me to trace it with care from Loch 

 Eishort to the eastern shore, by which proceeding they will pro- 

 bably succeed in determining 'that which I am compelled to leave 

 in doubt, but I may nevertheless describe its leading features. It 

 is by no means regularly stratified, nor is it possible to trace for any 

 considerable distance even the fragments of a regular prolongation 

 of the edges of beds, such as is so distinctly exhibited in the quartz 



Vol. III. E 



