79 



sufficient inorganic plant-food to make it, if judiciously 

 treated, once more " the Garden of the East." Surface 

 and subsoils of Salsette. Difference of chemical compo- 

 sition. The improvement of the soil by heat, moisture, and 

 atmospheric air. A knowledge of the condition of his 

 soil necessary to the farmer. The means to change the 

 inorganic plant-food from the unassimilable to the assimi- 

 lable state. The mechanical operations of agriculture. 

 Their meaning and purport. TheTesults depend upon the 

 amount of inorganic plant-food present. The help of 

 science to ascertain what is wanted. Drainage. The use 

 of manures to aid the mechanical operations of agriculture. 

 Lime. Common salt, saltpetre, ammonia. Colonel 

 Corbett adding to the evidence of the exhausted nature of 

 India's soil. Irrigation, with constant cropping, hastens 

 the impoverishment of the soil : wheat-lands degenerate 

 into rice-lands, rice-lands are abandoned to reeds and 

 rushes. Irrigation will impoverish the soil unless a different 

 system of cultivation is adopted, and the balance of 

 inorganic plant-food more carefully preserved. The 

 Oriental on irrigation-works in India, and manures. The 

 natural state of the plant compared with its artificial or 

 cultivated state. The difference between soils bearing a 

 natural growth of plants and those under cultivation by 

 mankind. The enrichment of the one and the impoverish- 

 ment of the other. 



THE general functions which the soil has to fulfil 

 in vegetable life have already been pointed out in 

 the foregoing pages : it has been shown that the 

 incombustible or inorganic constituents of plants 

 are exclusively derived from it. The great impor- 

 tance of these constituents, and the powerful 

 influence they exercise upon vegetable life, 

 render an intimate knowledge of the chemical and 



