256 ANALYSES OF SOILS. 



tain large tracts of limestone, some of which is magnesian. The shape of the district is 

 quite irregular. 



One of its most important features is the occurence of an extensive bed of clay, and its 

 accompanying sands. It is quite impossible to arrive at a satisfactory conclusion in re- 

 gard to the origin of this formation. The shales and slates of the Hudson river, when 

 they decompose, form a clay ; and in the sands, we often detect, with a microscope, small 

 particles of anthracite, which substance is known only in the Calciferous sandstone, and 

 in disseminated particles in some of the Hudson river shales. These facts taken by them- 

 selves, together with the large amount of calcareous matter the clay contains, seem to 

 indicate that the clays and sands originated from the rocks of the Champlain division. In 

 many places, however, the magnetic iron sand is quite abundant, which can only be de- 

 rived from the primary. These combined facts lead us to infer that both systems of rocks 

 furnished materials for the formation of the clays and sands of this district. Hence it 

 would seem that a part of the materials under consideration were not transported far, but 

 were derived from rocks in the immediate vicinity of the deposits themselves. 



We propose to begin our analyses with the soils of the Mohawk valley, in which we find 

 those that may be considered as characteristic of the district, or that may be taken as re- 

 presentatives of the general composition of its soil. 



Soil of De Grojfs flats, betioeen Amsterdam and Fonda. 



ANALYSIS. 



Water of absorption 4*50 



Vegetable matter 7*37 



Silex 78-83 



Peroxide of iron and alumina 6*50 



Carbonate of lime 2-00 



Phosphate of lime 0-03 



Magnesia 0*40 



99'63 



The flats from wliich this soil was taken, are probably as productive as any in the Mohawk 

 valley. The soil is dark colored, from the large amount of vegetable mould upon and 

 near the surface. It is underlaid by the Utica slate, fragments of which are scattered 

 through the soil to a considerable depth. Notwithstanding this, it may be properly con- 

 sidered an alluvial soil. 



On ascending from one to four hundred feet above the meadows or flats of the Mohawk, 

 we are able to distinguish soils of a difierent character, and differing from those below in 

 composition. Thus, four hundred feet above the Mohawk river, at Fonda, the soil is 

 composed as follows : '- - 



