CHAPTER II. 



ORIGIN AND PEOPERTIES OF SOILS. 



SOILS THE RESULT OF DISINTEGRATION CAUSES STATED BY SIR H. DAVY 



BOUSSINGAULT HITCHCOCK ALLUVIAL AGENCIES. PROPERTIES : 



SPECIFIC GRAVITY AFFINITY FOR MOISTURE ABSORPTION OF MOIS- 

 TURE FROM THE AIR CAPILLARY ATTRACTION STATE OF DIVISION 



COHESION AND ADHESION ABSORPTION OF GASES FROM THE AT- 

 MOSPHERE ABSORPTION AND RETENTION OF HEAT. 



^T^HE earth presents a great diversity of soils, 

 upon which widely different kinds of j^lants 

 flourish, each adapted to some peculiar genus, 

 species, or variety of plant in the vegetable king- 

 dom. The failure of one orchard, while another, 

 receiving the same treatment, succeeds, evinces the 

 necessity of a proper selection of the land for the 

 growth of fruit. 



" All soils are the result of the disintegration and 

 decomposition of rocks, with the addition of saline 

 and decayed vegetable and animal substances." The 

 materials derived from the rocks constitute by far 

 the larger part, and therefore by an examination of 

 these we can form an idea of the composition of the 

 soil produced from them. Soils may be almost 

 wholly composed of disintegrated rocks, in which 

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