144 BOARD OF AGRICULTURE. 



the power to produce them perpetually, make the mighty 

 aggregate of the nation's present and prospective income. 



The great object of cultivating the soil is to produce plants. 

 But plants are not produced by a mysterious power from noth- 

 ing. They are formed in accordance with natural law out of 

 materials previously created and deposited in the soil and in 

 the air. Plants, animals and soil are of one and the same ma- 

 terial, simply changed in form, composed alike of the organic 

 substances, carbon, oxygen, hydrogen and nitrogen, and of the 

 inorganic substances, potash, lime, soda, magnesia, oxide of 

 iron, oxide of manganese, phosphoric acid, sulphuric acid and 

 chlorine. It is a mistaken notion that this great earth, with its 

 thousands of square miles of soil of unknown depth, is one 

 great reservoir of plant-food, on which they may grow to per- 

 fection, be removed, and the supply remain exhaustless. Not 

 one thousandth, or one ten-thousandth, of this great mass of 

 earth is in a condition to feed plants or to be transformed into 

 animal structures ; and that small portion has been made so by 

 the most slow and obscure of chemical and mechanical processes. 

 In this view, this soil which we tread so carelessly beneath our 

 feet, and which to the unthinking millions is simply so much 

 dirt, becomes one of the most wonderful and mysterious com- 

 pounds ; and the changes through which it passes, in its trans- 

 formation from the rough, raw earth to plants and animals, and 

 the laws which govern, which accelerate or retard, at any point 

 of the process, shyuld, if possible, be understood by the tiller 

 of the soil. Pulverized granite and sawdust, mingled, would 

 contain all the elements of plant-food — would be soil made up 

 in due proportions of organic and inorganic matter — but it 

 would not nourish plants, for the elements are not in an assim- 

 ilable condition. And this is precisely the original state of the 

 soil we cultivate — the state to which we can again reduce it by 

 removing the solvent portion. It is necessary that the sawdust 

 should be reduced to carbonaceous matter to give to this soil 

 color, absorbing and retaining power, to give it porosity, and 

 some portion of organic plant-food. It is necessary that the 

 pulverized granite should be taken to pieces ; its lime, its 

 potash, soda and phosphates should be released from the affin- 

 ities which hold them bound, and by chemical influences, be 

 brought to such a condition as to be solvent in water. Then, 



