XIV PEEFACE. 



selves the trouble of becoming thoroughly aequainted 

 with them. 



Many have reproached me with unjustly condemning 

 modern agriculture as a system of exhaustion. From 

 the communications addressed to me by many agricul- 

 turists as to their system of husbandly, I must exempt 

 them from such an accusation. There are, however, 

 but few among the general body who really know the 

 true condition of their soil. 



I have never yet met with an agriculturist who kept a 

 ledger, as is done as a matter of course in other industrial 

 pursuits, in which the debtor and creditor account of 

 every acre of land is entered. 



The opinions of practical men seem to be inherited 

 hke some inveterate disease. Each regards agriculture 

 from his own narrow point of view, and forms his con- 

 clusions of the proceedings of others from what he does 

 himself 



JUSTUS vox LIEBIG. 



Mi-xich: March 1863. 



