NORTH UIST. SOIL AND SURFACE. 127 



throughout the island, and with the addition of sand 

 from the shores, forms an excellent mould. Much of 

 the western shore consists of the same drifted sand 

 which is so abundant in the islands to the south of 

 this, and which, mixed with the peat in various pro- 

 portions by its natural tendency to spread over the 

 country, forms a light open soil applicable to the cul- 

 tivation of barley and potatoes, particularly when ma- 

 nured, as is the practice of the country, with drift sea 

 weed. The remainder of North Uist, comprehending 

 the hilly region and the watery tract, is a mere mass 

 of peat, producing little but the heath, rushes, and 

 scanty grasses usual in similar soils, except in a few 

 spots where by the assiduity of the small tenants or 

 crofters, it is rendered capable of yielding an occasional 

 crop of barley or potatoes. 



The peat in this countiy is in general of considerable 

 depth, reaching from ten to twenty feet downwards, 

 and almost always incumbent on a body of alluvial 

 gravel, or on the bare rock. In some situations it is 

 found to repose on a bed of fine and soft, but not 

 tenacious, pale greyish clay, which on burning is con- 

 verted into a white powder, and applied by the natives 

 to the purposes of scouring or polishing metallic utensils. 

 It is a porcelain clay resulting from the decomposition 

 of the felspar in the gneiss. 



The peat of North Uist, as well as that of many 

 other parts of the Long Island, is in a state of extreme 

 decomposition at its lower parts. On this account it 

 forms when dried a compact substance of great density, 

 which is incapable of being again affected by exposure 

 to rain, and which requires therefore no protection when 

 completed. Its specific gravity is much greater than that 

 of ordinary peat. It bums with so bright a flame as 

 to supersede the necessity of light in the cottages of 

 the natives, and with a glow of heat equal to that 

 of the inferior kinds of coal, while it i$ capable of 



