FERTILE SOIL. 107 



This is a most remarkably rich soil, and few 

 in the world can compare with it in furnishing 

 the raw material for producing bread and meat. 

 The farmer can see at a glance, that it contains 

 every substance necessary for the growth of 

 plants. As it would be interesting to know how 

 much of each of the elements is contained on an 

 acre of the above-mentioned soil, assuming the 

 soil to be ten inches deep, and hence weighing 

 one thousand tons, we give the result of the 

 calculation, as follows : 



Silica and Alumina 576*0 tons. 



Soluble Silica 23-0 



Soluble Alumina 18-0 



Peroxide of Iron. 90'0 



Protoxide of Iron 3'5 



Lime 40'0 



Magnesia 1*8 



Potash 10-0 " 



Soda 19-0 " 



Ammonia 1200-0 Ibs. 



Phosphoric Acid 4-5 tons. 



Sulphuric Acid 9'0 " 



Carbonic Acid 61/0 " 



Chlorine 12'5 " 



" Vegetable remains and water 83-0 " 



The commercial value of these quantities of 

 fertilizing elements can easily be estimated. 

 The reader will notice that the amount of lime 

 is four per cent., or forty tons to the acre. Allow- 

 ing that 200 Ibs. may be washed out and ap- 

 propriated yearly by growing crops, it would 



