JOHN S. GOULD'S ADDRESS. 621 



growth of corn. This has been shown from the great amount 

 of water existing in the plant. It is also necessary to dissolve 

 the saline and organic constituents of the soil, because they 

 cannot enter into the plant except in a state of solution. 



Moisture may be secured for the plant, 1st, by irrigation. 

 This process would be too expensive to be profitable, except 

 in a very few localities, and I therefore pass over it with the 

 simple allusion to its possibility. 2d. Moisture may be in- 

 creased by deep ploughing, subsoiling, and thorough pulveri- 

 zation. By deep ploughing and subsoiling, the roots have 

 access to a stratum less affected by evaporation, and which 

 therefore is more abundantly supplied with moisture. By 

 thorough pulverization, we enable the moisture from below to 

 pass upward by capillary attraction. More dew also is de- 

 posited on a well pulverized surface than on a hard one. 



III. Access of air is also essential to the growth of corn. No 

 matter how rich a soil may be in vegetable matter, it cannot 

 possibly yield any food to the crop in the absence of air, be- 

 cause it can only be absorbed by the plant in a state of trans- 

 formation induced by its combination with oxygen. Other 

 things being equal, those soils bear the greatest crops of corn 

 which are most readily permeated by air. 



" In a soil to which the air has no access, or at most but 

 very little, the remains of animals and vegetables do not decay, 

 for they can only do so when freely supplied with oxygen, but 

 they undergo putrefaction, for which air is present in sufficient 

 quantity. Putrefaction is known to be a most powerful deox- 

 idizing process, the influence of which extends to all surround- 

 ing bodies, even to the roots and the plants themselves. All 

 substances from which oxygen can be extracted yield it to 

 putrefying bodies; yellow oxide of iron passes into the state 

 of black oxide, sulphate of iron into sulphuret of iron, &c. 



" The frequent renewal of air, especially its contact with alka- 

 line metallic oxides, the ashes of brown coal, burnt lime or 

 limestone, change the putrefaction of its organic constituents 

 into a pure process of oxidation; and from the moment at 

 which all the organic matter existing in a soil enters into a 

 state of oxidation or decay, its fertility is increased. The 

 oxygen is no longer employed for the conversion of the brown, 

 soluble matter, into the insoluble coal of humus, but serves for 



