C 4 ] 



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 to illustrate it, in a distinct course 

 of public lectures. 



Agricultural Chemistry has for its objects all 

 those changes in the arrangements of matter connect- 

 ed with the growth and nourishment of plants ; the 

 comparative values of their produce as food; the con- 

 stitution of soils; the manner in which lands are en- 

 riched by manure, or rendered fertile by the different 

 processes of cultivation. Enquiries 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 afford- 

 ing simple and easy experiments for directing his la- 

 bours, and for enabling him to pursue a certain and 

 systematic plan of improvement. 



It is scarcely possible to enter upon any investiga- 

 tion in agriculture without finding it connected, more 

 or less, with doctrines or elucidations derived from 

 chemistry. 



If land be unproductive, and a system of ameliorat- 

 ing it is to be attempted, the sure method of obtaining 

 the object is by determining the cause of its sterility, 

 which must necessarily depend upon some defect in 



