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 Be Groff's flats , between 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 which 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 different character, and differing from those below in 
composition. Thus, four hundred feet above the Mohawk river, at Fonda, the soil is 
composed as follows : 
