VI PREFACE. 
of the reach of the ordinary inquirer, and to set them 
forth in proper order and in plain dress for their legiti- 
mate and sober uses. 
It has cost the Investigator severe study and labor to 
discover the 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. 
