246 , 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 Schodaek, in Rensselaer county. 



ANALYSIS. 



Water 4-25 



Animal and vegetable matter 6*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 o/" 100 grs. of Welch slate. 



Water 0-34 



Organic matter 2-30 



Silex... 78-7G ^ 



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 lees soluble ; and 

 hence, too, in a few instances where the soil has been cultivated, magnesia is present in a 

 greater proportion than lime. 



