THEORY OF SOIL FERTILITY 185 



count, on which every crop is a check marching 

 inevitably toward insolvency, if he fails to 

 return as much food as he takes out? Is it 

 true that after less than two generations of 

 farming we have produced so extensively, 

 taken so much innate fertility out of the soil 

 for home consumption and to satisfy the in- 

 ternational balance of trade, that we must now 

 begin to rob Peter to repay Paul? 



All that Jeremiah hears, if he listens to the 

 counsel of the official preceptors of his state 

 experiment stations, to the editorials of his 

 rural papers, or to the advice of the man who 

 has chemical plant food to sell, is that the 

 danger of soil exhaustion is not something re- 

 mote and mythical, like the advance of the 

 polar ice cap toward the equator, but a con- 

 dition that is actually upon him, threatening 

 starvation for himself and his children. 



On the other hand, if he be sufficiently in- 

 terested or frightened to delve deep into the 

 mountain of literature on the subject, he will 

 find hidden away, discredited by the huge 

 army of preceptors who have grown up since 

 Liebig, a pronunciamento by the Bureau of 

 Soils of the United States government, which 

 says: 



