SOILS AND MANURES 



27 



by the air, but liable to dry up. There are, how- 

 ever, exceptions to this general rule. In some 

 parts of the eastern counties of England there are 

 large tracts of land composed of calcareous sand. 

 These soils are apt to become binding rather than 

 dry on the surface, and as such they are more 

 fertile than loosely-constituted silicious soils. Usu- 

 ally loose sandy districts are very unfertile when 

 planted with fruit trees, especially Peach trees. 

 Such soils should be mixed largely with stiff 

 alluvial loam, and have rich surface dressings and 

 mulchings in times of drought. Soils thus treated 

 are much improved, but whilst the Peach grows 

 fairly in them, the fruits, though of good flavour, 

 are not large. In order to supply carbonate of 

 lime freely, powdered lime rubbish and gravel 

 mixed (so as to separate the particles), the whole 

 spread over the surface, would gradually find its 

 way by the infiltration of water all through the 

 soil. Thus only could a silicious earth, rendered 

 firm by clay with lime added, be called a fair 

 Peach soil. Pure silex is extremely barren. 

 When, however, it appears of a reddish colour it 

 indicates the presence of oxide of iron, which com- 

 bines readily with the oxygen of the atmosphere 

 and retains it. These ferruginous soils are ex- 

 cellent. When silex is in too great a quantity 

 there is an abundance of blossom, but the fruits 



