180 THE FARMER OF TO-MORROW 



mine and adding plant food to the soil differ 

 only in degree. One is criminal, while the 

 other is preached officially as scientific and 

 ethical. 



The value of a gold mine is appraised, not 

 by the amount of gold that is being taken out 

 of a shaft, but by the reports of a trustworthy 

 body of engineers who have examined the 

 geological formation to which the mine owes 

 its richness, and determined the extent of the 

 lode. Such a mine might produce 5 per cent, 

 net during the first year of its exploitation, 

 and continue to produce at the same rate for 

 twenty years. At the end of its twentieth 

 year it still produces 5 per cent, net, until it 

 is mined of the last ounce of gold it contains. 

 The only way to take more gold out of that 

 mine is to put more gold in. Therefore the 

 shares of that mine are not valued as a 5 per 

 cent, investment in the end, but as assets which 

 have shrunk to 5 per cent, of their original 

 value. 



Apply the same principle to the fertility 

 of the land. It is not so far-fetched as it seems 

 at first glance, because we are told that already 

 a large area of our farms has reached a point 

 where artificial fertilizers, "salt," are required, 



