THE NEW EARTH 



essential as a part of any economic system 

 which shall maintain the fertility of the soil ; 

 and for the successful growing of legumes the 

 presence and assistance of the proper species of 

 nitrogen-gathering bacteria are also absolutely 

 essential." 



While other methods of restoring depleted 

 soils may not at once be abandoned, and while 

 sensible rotation of crops will still be followed, 

 yet enough has already been demonstrated 

 to show that soil inoculation is preeminently 

 practical, although before successful inocula- 

 tion can be secured all other essential condi- 

 tions of the soil must be supplied. Soils, like 

 gold mines, are liable to become exhausted 

 after long working. For a number of years, 

 like the mines, they may yield a large income, 

 for several years longer they may pay ex- 

 penses, but there comes a year when the 

 farmer, like the gold miner, cannot make both 

 ends meet out of the profits of his investment. 

 Here, however, the likeness ends, — the farmer, 

 unlike the miner, may put back the gold 

 into his acres. 



Artificial nitrogenous fertilization in a sense 

 is like the miner's restoration of his mine 



46 



