154 GNEISS. 



thousands of irregular and naked rocky eminences, of 

 various elevations, cover the surface; separated indeed 

 hy intervals of herbage, and by stagnant pools, yet so 

 that a distant prospect presents the appearance of one 

 continued pavement of solid stone. Where the ele- 

 vation of the ground increases, the prevailing features 

 of the country resemble the granite ridge of Dartmoor 

 and Cornwall; the hills, further, gradually assuming a 

 mountainous character, while the outline still con- 

 tinues tame and rounded, with few projecting rocks or 

 precipitous faces. At length, without any material in- 

 crease of elevation, the mountains of gneiss start up 

 into craggy and abrupt summits, as in Sutherland, in 

 Inverriessshire, and elsewhere: the district of Knoydart 

 forming one of the wildest tracts in all Scotland, and 

 combining more varied forms of grandeur than any 

 part of the western coast. 



The relative effects of the two leading divisions 

 of gneiss on the soil and produce of the country, 

 is also worthy of notice. Where the schistose 

 variety prevails, the character of the soil is equal 

 or superior to that which is the produce of micaceous 

 schist. Where the granitic variety occurs, it generally 

 resists the ordinary disintegrating powers; whence 

 that peculiar nakedness of the surface already men- 

 tioned. Considering the close resemblance between 

 this rock and granite, the reasons are not obvious; 

 further than as it may depend on the absence of fis- 

 sures, denying access to water, and to consequent 

 frost. Hence also arises that absence of soil so 

 remarkable in most of the Scottish gneiss islands, 

 though no general rule can be derived from this fact: 

 as, in many other countries, even the granitic gneiss 

 decomposes as readily as some granites, forming 

 a deep and rich soil ; as in Guernsey, and also in 



