PRACTICAL AGRICULTURAL 

 CHEMISTRY 



The processes involved in agricultural chemistry- 

 are naturally more obscure and more complex than 

 those studied in the inorganic and organic departments 

 of the pure science, as so many external factors arise 

 to complicate the chemical changes taking place. Owing 

 to the fact that both plants and animals are living beings, 

 and are affected so largely by individuality, environ- 

 ment, and other external causes, the chemistry connected 

 with their growth, feeding, etc., will naturally not admit 

 of such uniform investigation as is applicable to the 

 other branches of chemistry. The soil also is the seat 

 of chemical changes so obscure, so gradual, and at 

 present so little understood, that the pure chemist may 

 well be appalled at the problems which arise, and the 

 difficulties that are to be met with, in a study of the 

 soil from the point of view of plant nutrition. 



The practical methods of investigation employed in 

 agricultural chemistry are, it must be admitted, generally 

 of a very empirical standard, although a knowledge of 

 the more exact methods used in pure chemistry is 

 absolutely essential for a correct understanding of the 

 meaning and underlying reasons of the results obtained. 



The need for the recognition of such indefinite factors 

 as palatability in the case of animal food-stuffs, the fact 



A 



