HIGHLAND DISTRICT. 237 



State which furnishes a soil whose origin is directly from the Primary rocks. The latter 

 district is quite limited in comparison with the former ; and its soil, in consequence of a free 

 intermixture with the soils of a secondary and transition origin, can not be considered as 

 entitled to the appellation of a primary soil, or as one derived principally and directly from 

 primary rocks. Both divisions of the Highland district are surrounded with sedimentary 

 rocks, and are really islands of unstratified masses in the midst of sandstones, limestones 

 and slates. These have at least modified the soils of the borders of the district by the 

 admixture of foreign materials, the result of which has been to improve their character and 

 increase their productiveness. 



The primary masses of the Northern district are capable of producing two kinds of soil, 

 according as one or the other kind of granite, from which they have originated, prevails. 

 The first and most common kind of soil is that which is derived from the potash-felspar, 

 or the ordinary coarse granite ; the second, is the lime-felspar, which belongs to the 

 hypersthene rock, which is made up, in a very large proportion, of labradorite. The 

 outside of this primary highland region is principally underlaid with the former, while 

 the central or interior is composed of the latter. All the high mountains are formed of the 

 latter rock. They are quite precipitous, and their sides thinly clad with soil whose im- 

 mediate origin is the rock beneath. The appearance and character of the surface of the 

 rocks, when exposed, clearly indicates that the rock undergoes decomposition : it is often 

 covered with the fine powder derived from the felspar. This rock is destitute of mica, 

 another mineral whicli is common in granites, and which assists, by its decomposition, in 

 supplying the soil with the alkalies. As lime is the principal alkali in the hypersthene 

 rock, we must of course expect to find it in the soil formed of this rock, and the analysis of 

 many soils of this region confirms this expectation. 



The first variety of granite produces a soil which contains a larger proportion of the 

 silicates of alumina and potash, while the soils formed from the latter variety yield a 

 greater amount of the silicates of lime and alumina. The virgin soil of either kind pro- 

 duces a very large growth of grass. The wild grasses only are found in the natural 

 meadows, which yield about a ton and a half per acre. But when timothy is first sown, or 

 when hy accident its seeds are scattered by the road side, its growth and size are truly 

 remarkable : it not unfrequently attains a height of five feet, and its stems are as coarse as 

 rye straw. This fact is worthy of notice ; for this gigantic growth is undoubtedly due, 

 first, to the abundance of alkaline earth in the soil, and, secondly, to the light vegetable 

 mould in which it takes root. 



Composition of the soils of the highland district. 



It was not considered important to analyze a great number of the soils of this district, as 

 we wished to learn merely their general character and composition. The samples were 

 all selected from Essex county, inasmuch as here they are entirely of a granitic origin, 

 without a perceptible intermixture of sedimentary rocks. A specimen of this soil, collected 



