GLENTILT. 367 



particularly to the mass we are speaking of; in 

 which the veins and nodules of felspar, found 

 terminating in every direction, and the apparent 

 angular masses of hornblende, obviously belong 

 to the natural structure of the stone, and could 

 not possibly have been injected by external force. 

 The existence, in fine, of calc-spar, as a frequent 

 material in this rock, appears decisive against the 

 supposition of its igneous origin. 



To the south of the bridge, a large bed: of 

 granular limestone runs along the face of the 

 acclivity at a considerable height, and, I suppose, 

 at some distance up the river crosses the channel 

 in a conformable direction. Two miles above 

 the Lodge, the sienitic greenstone contains calc- 

 spar coloured by hornblende. Common primitive 

 greenstone is also found at different places. Fur- 

 ther still, and at a small distance from the Tarf- 

 Linn, the hornblende and felsp&r, in this spe- 

 cies of rock, assume a peculiar and distinct 

 granular form, which is sometimes obser- 

 ved on a great scale. Here we find veins con- 

 sisting of aggregated felspar, quartz and horn- 

 blende. Mica-slate then re-appears, with stripes, 

 of quartz, immediately below the Tarf-Linn, 

 and seems to form the rock over which the 

 stream there precipitates itself. Beyond the 

 Linn, on the way to Braemar, the rocks are 

 composed, along the channel of the Tilt, of a 

 coarse quartzy substance, which is penetrated 

 with veins of shining quartz, and appears to be 



