XXXVlll INTRODUCTION. 



experience, and have proposed no new methods, except- 

 ing those, the superiority of which over the old ones ap- 

 peared to me to be fully confirmed. It is particularly 

 important in agriculture to be cautious of innovations. 

 There is not amongst husbandmen, generally speaking, 

 a sufficient degree of knowledge to enable them to ap- 

 propriate the suitable soil and climate to foreign produc- 

 tions ; their best plan therefore is, to wait till some 

 neighbour more enlightened than themselves can exhibit 

 to them specimens of improvements ; which they may 

 imitate without running much risk of ill success. 



1 shall perhaps be accused of having permitted myself 

 to make some repetitions, and I candidly acknowledge 

 that I have not endeavoured to avoid them. In a 

 work like this, the subjects which are treated may often 

 be prescDte I under different forms ; their phenomena 

 always result from the same principles, but they may 

 be most clearly elucidated by varying the modes of ex- 

 plaining them. I have treated each subject in a manner 

 entirely independent of the rest ; I have called to mind 

 all the facts that could throw light upon it ; I have de- 

 duced from them those principles which ought to direct 

 the agriculturist in his labors ; and I have not feared to 

 repeat a truth as often as I thought it could be done with 

 advantage. 



This work is not perfect, and I can myself judge of 

 its imperfections better than anyone else; but, such as 

 it is, I believe it will be found useful. I trust that the 

 application of the physical sciences to agriculture will 

 be extended in proportion as those sciences advance ; 

 and that a more thorough knowledge of the principles 



