2 46 
ANALYSES OF SOILS. 
sought for. The chloride and sulphate of lime are also invariably present. The organic 
matter is also in combination with lime and other bases, varying from one to two per cent. 
Soil from the western part of Schodack , in Rensselaer county. 
ANALYSIS. 
Water_ 4*25 
Animal and vegetable matter_ O’75 
Silex.79-75 
Peroxide of iron... 2-75 
Alumina_ 4*50 
Lime and magnesia. 0-50 
98-50 
Loss__________ 1 -50 
100-00 
Analysis of 100 grs. Roofing slate. 
Water_ 0-50 
Organic matter_ 2-20 
Silex.. 80-72 
Peroxide of iron and alumina_ 12-76 
Carbonate of lime_ 1-76 
Magnesia___ 0-40 
98-34 
Analysis of 100 grs. of Welch slate. 
Water_ 0-34 
Organic matter_ 2-30 
Silex_............78-76 
Peroxide of iron and alumina_ 16-64 
Carbonate of lime_ 1*36 
Magnesia_ 0-52 
99-92 
The slates of this district, we believe, always contain magnesia, as well as the limestones, 
some of which, it is well known, are true dolomites. Hence magnesia is always found in 
the soil, and it does not seem to be removed so readily as lime, being less soluble; and 
hence, too, in a few instances where the soil has been cultivated, magnesia is present in a 
greater proportion than lime. 
