* DRIFTED SOILS 43 



In applying the preceding fuels, it is easy to see how farms and estates should be selected 

 in a primary district. Tiie depth of soil is an important fact, as is well known, but its 

 derivation is another (Hjually important. For its deiermination, the outcrop of rocks upon 

 hillsides may be examined, and their nature ascertained ; whether their exposed or weathered 

 surfaces are bleached, and softer tlian that of a recent fracture; or whether they arc 

 crumbly, and disposed to disintegrate. If the rocks are hornl)lende or pyroxenic green- 

 stone, or a coarse granite with large masses of felspar, we shall expect the soil to contain 

 the alkalies or alkaline earths ; and if by cultivation they become exhausted, we may 

 expect that by deep or subsoil ploughing a fresh quantity can be l>rought to the surface 

 for the use of vegetables, and ilius a constant reproduction of them obtained from the 

 decomposition of the coarser particles now intermixed with ilie deeper soil. Greenstone 

 and trap, from their more ready disposition to undergo change, may be ranked among the 

 best materials for a foundation soil, possessing all the requisites desired for the cultivation 

 of grains and fruits. They are not so porous as the granitic sands that are termed leechy; 

 nor so compact as many of the argillaceous soils, manj' of which retain the water in pools 

 upon the surface. 



§ 5. Drifted soil. 



A farther consideration of the causes which have distributed the soil and spread the 



debris of rocks at a distance, is of some importance while treating of the northern counties ; 



as it may appear to those who are familiar with the drift or diluvial theories, that little 



reliance can be placed on our instructions for determining the character of the soil iiy 



observing the rocks beneath. It is true that we find the debris of distant rocks in most of 



our soils; yet we find that their essential character is, with some exceptions, derived from 



the rock near by. On the northern and nortliwestern slope of the highlands in Franklin 



county, many boulders of Trenton limestone may be found, which, together with some of 



the finer matters, were brought from the Canada side, and probably this transported debris 



exerts some influence ; still thereMs a predominance of soil from the Potsdam sandstone, 



the underlying rock of a great part of the county, particularly the northern part. In the 



neighborhood of Malone, immense drift beds have been accumulated, in which the 



boulders of this sandstone always predominate. They have also been transported south, 



and lap on to the primary masses, and modify the soil of the granite and gneiss; but when 



we penetrate deeply into this great primary region, its distinguishing characters axe derived 



from the masses beneath. In some instances the drift current has left nothing but loose 



boulders, which, resisting decomposition, all the soil we now find is of modern or recent 



origin. Narrow formations, whose strike is east and west, will usually be covered with a 



more distant soil than those whose strike is north and south. Of this fact, we shall have 



occasion to speak hereafter. 



6* 



