of Granite and Sandstone in Sutherland. 279 



but for a space not exceeding a few feet, the appearance of 

 stratification is perfect. Here the surface of the granite 

 touches the sandstone by a level plane; and, immediately 

 following that junction, are three or four laminae of an argilla- 

 ceous nature, or of a shale imbedded in the granite, so as to 

 divide it into three or four corresponding laminae. I must add, 

 that the whole thickness of this species of stratification, or 

 laminar structure, does not much exceed a foot. 



As this remarkable point is the most obvious and easy of 

 access of the whole, the first impression it conveys serves to 

 confirm that suggested by the more distant view just men- 

 tioned, namely, that the granite is regularly stratified and 

 graduates into the sandstone. 



The appearances are indeed such as, on a first view, not to 

 seem to admit of any doubt ; and, unquestionably, an observer 

 who had predetermined that this was the ordinary relation of 

 granite and sandstone, would quit the spot with a thorough 

 conviction in his mind ; and imagining a complete demonstra- 

 tion of it to be here found, would enter it accordingly in his 

 note-book. Yet a more accurate investigation will show that 

 the appearance is very partial, and that no real indications of 

 stratification in the granite, beyond that mentioned, exist. I 

 must remark, however, that the particular spot now cited is 

 not the only example of this laminar appearance on the sur- 

 face of this granite; since, in one or two other places, where 

 that surface is bare, there adhere to it portions of laminae, or 

 small strata, resembling these already mentioned. 



The mineralogical nature of these rocks is even more re- 

 markable than the geological circumstances that have been 

 detailed. 



The granite has, in many parts, the most ordinary aspect 

 and characters ; but where it approximates to the sandstone, 

 it consists of quartz and felspar. In some places only, these 

 minerals are equally intermixed in large grains ; in others, large 

 grains of each are united in a sort of general basis, or paste, of 

 finer sand. In one variety, of remarkable appearance, the 

 large grains of felspar are of a high red colour, when that 

 mixed with the quartz in the paste is white. The effect of 

 this peculiarity of structure can scarcely be appreciated in de- 



