CLASSIFICATION OF SOILS. 403 



extensive tracts of them, especially in the north. A geological 

 survey of the Island of Great Britain has been executed with 

 great skill, and the various geological formations distinctly indi 

 cated on a map ; but such have been the extraordinary convul 

 sions on the earth s surface, that the geological lines are not an 

 infallible guide to the character of the soil. It may be safe, in 

 general, to infer the character of the soil from the nature of the 

 rocks prevalent in any particular locality ; but the diluvial and 

 alluvial deposits often differ entirely from the character of the 

 rocks which lie beneath them. No knowledge of the geological 

 formation of a country, therefore, so far as its cultivation, and 

 the general character of the crops to be raised, are concerned, 

 will supply the place of personal observation and experience. 



If the nature of the soil were the only circumstance to be 

 taken into consideration in determining the character of the 

 agriculture to which it is adapted, the mode of cultivation, and 

 the crops to be grown upon it, the whole subject would evidently 

 be greatly simplified ; but the climate, including heat and mois 

 ture, and the aspect and elevation of the land, are quite as much 

 concerned in every question connected with this subject. 



LXVIII. CLASSIFICATION OF SOILS. 



For all practical purposes, soils may be ranked under five 

 different heads sandy, clayey, calcareous, peaty, and loamy. 

 I purposely avoid all scientific distinctions, and use such terms 

 as even the commonest farmer will understand. A sandy soil 

 is that in which sand abounds ; clayey, in which clay ; calca 

 reous, in which lime in some form prevails ; peaty, in which 

 peat ; loamy, in which a rich loam abounds. These soils are 

 sometimes found so combined, that it might be difficult to desig 

 nate their character by any one of these general terms. In some 

 places, they are found in almost a pure state. In general, where 

 there is found in a soil 80 per cent, of sand, it must be pro 

 nounced a sandy soil ; and so the clay, the peat, or the lime ; but 

 it is not always easy to class a soil which is of a mixed char- 



