1 < 
short time only : the doctrines have not as yet 
been collected into any elementary treatise ; and 
on an occasion when I am obliged to trust so much 
to my own arrangements, and to my own limited 
information, I cannot but feel diffident as to the 
interest that may be excited, and doubtful of the 
success of the undertaking. I know, however, that 
your candour will induce you not to expect any 
thing like a finished work upon a science as yet in 
its infancy ; and I am sure you will receive with 
indulgence the first attempt made in this country 
to illustrate it, by a series of experimental demon- 
strations. 
Agricultural Chemistry has for its objects all 
those changes in the arrangements of matter con- 
nected with the growth and nourishment of plants ; 
the comparative values of their produce as food ; 
the constitution of soils ; the manner in which 
lands are enriched by manure, or rendered fertile 
by the different processes of cultivation. Enqui- 
ries of such a nature cannot but be interesting and 
important, both to the theoretical agriculturist, 
and to the practical farmer. To the first they are 
necessary in supplying most of the fundamental 
principles on which the theory of the art depends. 
To the second they are useful in affording simple 
and easy experiments for directing his labours, 
and for enabling him to pursue a certain and sys- 
tematic plan of improvement. 
It is scarcely possible to enter upon any inves- 
tigation in agriculture without finding it connected, 
more or less, with doctrines or elucidations de- 
rived from chemistry. 
