CHAPTER II 



The Origin of Soil 



Soil, or arable ground, is the surface of the 

 earth worked and stirred by our agricultural 

 implements, and in which plants are able 

 to develop their roots. In some places the 

 rock is bare and completely barren ; in 

 others the soil is a few inches thick, and 

 scanty grass will grow, while in others again 

 it reaches a sufficient depth, and vegetation 

 succeeds. But nowhere is this soil of un- 

 limited thickness. At no very great depth 

 the bare rock of the neighbouring mountains 

 reappears. How then has this bed of earth 

 been formed whence all food proceeds — for 

 the plant, for the animal, and for man ? 



Mined every winter — and on high moun- 

 tains the whole year long— by the ice which 

 is formed in their smallest fissures, rocks of 

 all kinds break into tiny fragments, separate 

 into grains of sand, fall in dust and provide 

 the powdered mineral matters which are 



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