A clayey subsoil will sometimes be of material 

 advantage to a sandy soil; and in this case it will re- 

 tain moisture in such a manner as to be capable of 

 supplying that lost by the earth above, inconsequence 

 of evaporation, or the consumption of it by plants. 



A sandy, or gravelly subsoil, often corrects the 

 imperfections of too great a degree of absorbent power 

 in the true soil. 



In calcareous countries, where the surface is a 

 species of marie, the soil is often found only a few 

 inches above the limestone; and its fertility is not im- 

 paired by the proximity of the rock; though in a less 

 absorbent soil, this situation would occasion barren- 

 ness; and the sandstone and limestone hills in Derby- 

 shire and North Wales, may be easily distinguished at 

 a distance in summer by the different tints of the ve- 

 getation. The grass on the sandstone hills usually 

 appears brown and burnt up; that on the limestone 

 hills, flourishing and green. 



In devoting the different parts of an estate to the 

 necessary crops, it is perfectly evident from what has 

 been said, that no general principle can be laid down, 

 except when all the circumstances of the nature, com- 

 position, and situation of the soil and subsoil are 

 known. 



The methods of cultivation likewise must be dif- 

 ferent for different soils. The same practice which will 

 be excellent in one case may be destructive in another. 



Deep ploughing may be a very profitable practice 

 in a rich thick soil; and. in a fertile shallow soil, situa- 

 ted upon cold clay or sandy subsoil, it may be ex- 

 tremely prejudicial. 



