Food for Plants. 9 



use, for the Nitrate in supplying an abundance of nitro- 

 genous food to plants, imparts to tliem a thrift and vigor 

 which enables their roots to gather in the shortest time 

 the largest amount of other needed foods from a greater 

 surface of surrounding soil. The increased consumption 

 of phosphoric acid and potash is due to the increase in 

 the weight of the crop. The office of the Nitrate is to 

 convert the raw materials of the soil into a crop ; for we 



i-:-:-:- 



obtain by its use, as Dr. Griffiths has tersely said, " the 

 fullest crop with the greatest amount of protit, with the 



least damage to the land.'' 



