284 ANALYSES OF SOILS. 



The Marcellus shales, and shales of the Hamilton group, which lie beneath the soil of 

 this farm, are composed of the following elements : 



Water of absorption 2-00 



Silicates 50-00 



AUimina and peroxide of iron 10 -00 



Carbonate of lime 36-90 



Magnesia 1-00 



99-90 



The shales of this range, which furnish undoubtedly a large proportion of the soil of the 

 eastern slope of the lake, are more calcareous than those of the Helderberg range ; and 

 hence it is probable that tiie large percentage of lime which the soils of Aurora yield, is due 

 to the composition of this range of rocks. It is apparent, too, from these and other analyses, 

 that a calcareous shale yields a soil richer in carbonate of lime than does a pure limestone. 

 The soil resting upon the Niagara or Onondaga limestone is usually quite deficient in this 

 element. This results from liie nature of the purer limestones, namely, the slowness of 

 their disintegration. 



A soil which rests on the same shales, three miles east of Manlius, has the following 

 composition : 



Water of absorption 2-00 



Vegetable matter 6-00 



Silicates 81-50 



Peroxide of iron and alumina 8-00 



Carbonate of lime 2-25 



Magnesia 0-25 



99-75 



A specimen consisting of 200 grains of soil, taken from Mr. Ellis's cornfield, based upon 

 the same rock, on being subjected to the action of water, gave 



Soluble matter 1-20 



Mineral salts 0-80 



Organic salts * 0-40 



The mineral salts consisted of _ 



Silica 0-02 



Chlorides of lime and magnesia 0-48 



Sulphate of lime 0-07 



Alumina 0-01 



Carbonate of lime 0-20 



0-78 



