CHAPTER XI 

 LIMING THE LAND: A CORRECTIVE FOR ACIDITY 



The use of lime in agriculture, especially its use as a 

 soil improver, was known in days of long ago: when 

 Rome was young, and Greece was struggling for the su- 

 premacy of the world. For Hesiod, the Greek, mentions 

 its use in his writings, and Cato and Pliny, keen Roman 

 observers, frequently discussed its importance in securing 

 the productiveness of the soil. In America, this same ob- 

 servation has not been wanting. For more than a century 

 in time, lime, as a soil improver, has been advocated by 

 successful farmers and planters, who, realizing its value 

 in the early agriculture of the country, gave it effectual 

 and constant trial, to their satisfaction and profit. 



The kinds of agricultural lime. The real source of lime 

 is in rock formation : out of these formations agricultural 

 limes are obtained. The following forms are common : 

 limestone rock, magnesia limestone, gypsum or land plas- 

 ter, marl, and oyster-shells. 



Ordinary limestone contains about fifty per cent, lime, 

 the remaining substances being carbonic acid, silicon, 

 iron, magnesium, and aluminum. When burned, the 

 product resulting and known as lime is nearly pure, and 

 weighs about ninety pounds to the bushel. When water 

 slaked, this amount increases to three times the original 

 weight. 



Magnesia limestones vary in composition, the best of 

 them containing about eighty per cent, of lime. Mag- 

 nesia lime may be substituted for ordinary lime as a 



