8 



ofji ho.'ilthy and efficient aj^ri cultural literature, 

 it is true, that a number ul treatises on this 

 ancient Jind in(lis])ensal>le art were written by 

 distinguished men belon«^in;^ to the two most cul- 

 tivated nations ol' anti(|uity — the Greeks and the 

 Itonians — and in such of their works or fragments 

 as have come down to us, we find interspersed 

 not a little that is excellent and practical, from 

 which we might profit in the present day. These 

 writings, however, and even those of a much later 

 date, contain, as Lord Bacon said, ^^ no principles;^ 

 that is, they are, notwithstanding the many valu- 

 able and practical directions which they contain, 

 essentially empirical. Indeed, it could not pos- 

 sibly have been otherwise, as agriculture was 

 incapable of being reduced to anything approach- 

 ing the condition of a scien^je, till chemistry and 

 and physiology, at least, assumed a definite form ; 

 a result that may be said to be quite recent. 

 Going back to the early part of the present cen- 

 tury, when Sir Humphrey Davy delivered his 

 celebrated lectures on agricultural chemistry to 

 the Board of Agriculture in England, and to the 

 report of Baron Liebig., on the same subject, to 

 the British Association for the Advancement of 

 Science, some thirty years ago, w^e discover the 

 cause of the mighty impulse that has in these 



