IMPROVEMENTS IN" AGRICULTURE. 29 



adaptation of them to any locality, constitutes the science 

 of agriculture — a science which calls forth a very great 

 degree of mental exertion for its acquirement, as a thorough 

 acquaintance with its principles and practice, demands a 

 knowledge of chemistry, geology, botany, meteorology, 

 zoology, and mechanics : and, moreover, requires more than 

 any other branch of industry, patience, research, observation, 

 and untiring zeal. 



The agriculture of temperate regions, whatever variety 

 it may assume, causes a certain exhaustion of the soil. 

 The cultivation of the cereals, particularly wheat, produces 

 this effect most speedily, large portions of the elements of 

 fertility being carried off in the grain. Even breeding and 

 dairy farms gradually suffer from the same cause, the 

 bodies of the animals in the one case, and the products of 

 the dairy in the other, abounding in mineral salts. In 

 every case the attention of the farmer ought to be directed 

 to the nature of the substances withdrawn from the soil, 

 and the most economical method of restoring them. 



In the ancient practice of agriciilture, these facts were 

 imperfectly understood, or totally lost sight of, and the 

 empirical methods pursued were often unsatisfactory, and 

 at best uncertain ; but from the recent labours of Davy, 

 Liebig, Shier, Johnston, ice, these uncertainties have been 

 removed, and the science reduced to certain rules, which 

 being based upon natural laws, are infallible, and capable 

 of adaptation to any circumstances. 



I have been led to make these remarks in order to show 



