CHAPTER VI 

 SOURCES OF LIME 



Nature's Provision. Soils are composed 

 of pulverized stone and organic matter. 

 Much of the original stone contained little 

 lime, and the human race would become 

 nearly helpless if there were no stores of 

 supply in the form of limestone, chalk, 

 marl, etc. The day would come when the 

 surface soil could not produce our staple 

 crops if its loss of lime continued, and a 

 means of replenishing the stock were not at 

 hand. The huge deposits of limestone that 

 have not been disintegrated by processes of 

 weathering are assurance that the soil's 

 need can be met forever. The calcium and 

 magnesium in the stone are in chemical 

 combination with carbonic acid forming 

 carbonates, and there is an additional mix- 

 ture of other earthy material that was de- 

 posited by the water when the stone was 

 being formed, but much limestone possesses 

 an excellent degree of purity. 



Confusion Respecting Forms. In the 

 public mind there is much confusion re- 



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