VI PUEFACE. 



of tlic roacli of the ordinary iu<iuirer, and to set them 

 forth in 2)roper order and in })lain dress for their legiti- 

 mate and sober uses. 



It has cost the Investigator severe study and labor to 

 discover tlie laws and many of the facts which are laid 

 down in the following pages. It has cost the Author no 

 little work to collect and arrange the facts, and develop 

 their mutual bearings, and the Reader must pay a similar 

 price if he would apprehend them in their true signifi- 

 cance. 



In this, as in the preceding volume, the Author's method 

 has been to bring forth all accessible facts, to present their 

 evidence on the topics under discussion, and dispassion- 

 ately to record their verdict. If this procedure be some- 

 times tedious, it is always safe, and there is no other mode 

 of treating a subject which can satisfy the earnest inquirer. 



It is, then, to the Students of Agriculture, whether on the 

 Farm or in the School, that the Author commends his 

 book, in confidence of receiving full sympathy for its 

 spirit, whatever may be the defects in its execution. 



