SOILS AND FERTILIZERS. 369 



with water and analyzing it might be supposed to furnish the desired 

 information. Bat the result proved otherwise and just as unsatisfac- 

 tory as a complete soil analysis, and for the reason, as finally ascer- 

 tained by numerous and laborious investigations, that soil possesses 

 the property of retaining and holding back these valuable constituents, 

 so that percolating water cannot remove them, while at the same time 

 they are sufficiently soluble to be taken up and appropriated by the 

 roots of the growing plant. 



The property of the soil, then, which prevents on the one hand the 

 deterioration of our fertile lands by the washing away by rain and in 

 drain waters of their valuable constituents, lends itself on the other 

 hand to their fixation and retention when given in the form of soluble 

 mineral fertilizer. Soluble potash and phosphoric acid worked into a 

 soil remain there, not to be washed away by rains; they are held as in 

 a bank which honors the legitimate drafts of the plants made through 

 their roots, but refuses payment to the demands of the never-resting 

 and ever-dissipating moving water. 



The large quantities of potash and phosphoric acid in our soils are 

 therefore valuable, but insoluble at present to a large extent ; their 

 value is hypothecated to the fature. By their gradual conversion 

 through atmospheric and other agencies of insoluble into soluble com- 

 pounds, they furnish a steady though limited supply of plant food for 

 a moderate crop ; but the demands of modern agriculture for large and 

 salable annual harvests, sufficient to yield a satisfactory return over 

 and [above their cost of production, is not responded to. True, im- 

 proved methods of cultivaMon will insure better returns, but only up 

 to a certain point, beyond which artificial ( i. e., mineral ) fertilizers 

 become a necessity. The readily available plant-food, the accumula- 

 tion of centuries, has been gleaned by our forefathers of their fertile 

 acres ; to us the choice is left of having time unlock similar treasures 

 yet in our soil, and in the meantime quit harvesting, or to supply the 

 deficiencies by becoming buyers, with the certainty of becoming to a 

 much larger extent sellers of our prodcts. 



THE PLANT. 



Every plant, as also every part of it, leaves on burning a certain 

 amount of ash. This incombustible material represents the mineral 

 constituents of the plant's body, and is different in amount as well as in 

 composition, not only for different species of plants, but also for differ- 

 ent individuals of the same species. Oats or wheat, or, in fact, any 

 other cultivated or uncultivated crop, yields results in this direction 



H— 24 



