110 



berless disappointments were the natural conse- 

 quence of this indiscriminate application of ma- 

 nures without any regard to the particular 

 requirements of the soil. For of all the varieties of 

 matter on this globe, there is none perhaps that 

 exhibits such a diversity, that differs so much in 

 its constituent parts, as the soil of our arable 

 fields. There are scarcely two fields nay, scarcely 

 two spots on the same field which contain their 

 mineral constituents in exactly the same proportion ; 

 and to recommend, therefore, the indiscriminate use 

 of specific manures to the agricultural public, 

 must be regarded as nothing short of wilful 

 deception. 



To use, for instance, the specific coffee manure, 

 which consists chiefly of potassa, for the ferti- 

 lization of a soil containing already an excess 

 of potash, would be a mere waste of time and 

 money, when a small addition of lime and magnesia 

 would have the desired effect. Again, what 

 benefit can accrue by manuring with superphos- 

 phate of lime a soil containing a large amount of 

 phosphoric acid, out of proportion to some of the 

 other constituents ? Or who would use lime as a 

 manure for a calcareous soil ? 



If a soil contains an abundance of potash, lime, 

 phosphoric acid, &c., while only a small quan- 

 tity of available silica is present, it follows that, 

 to make the soil yield a remunerative crop, of 



