144 MAKTKES. 



would be the case if no lime were used, only faster, 

 because the crop is larger), and in all judicious culti- 

 vation this loss will be fully compensated by the 

 application of manures, thereby preventing the ex- 

 haustion of the soil. 



Kind of lime to be used. The first consideration 

 in procuring lime for manuring land, is to select that 

 which contains but little, if any, magnesia. Nearly 

 all stone lime contains more or less of this, but some 

 kinds contain more than others. When magnesia 

 is applied to the soil in too large quantities, it is 

 positively injurious to plants, and care is necessary 

 in making selection. As a general rule, it may be 

 stated, that the best plastering lime makes the best 

 manure. Such kinds only should be used as are 

 known from experiment not to be injurious. 



Shell lime is undoubtedly the best of all, for it 

 contains no magnesia, and it does contain a small 

 quantity of phosphate of lime. In the vicinity of 

 the sea-coast, and near the lines of railroads, oyster 

 shells, clam shells, etc., can be cheaply procured. 

 These may be prepared for use in the same manner 

 as stone lime. 



The preparation of the lime is done by first burn- 

 ing and then slaking, or by putting it directly on 

 the land, in an unslaked condition, after its having 

 been burned. Shells are sometimes ground, and 

 used without burning ; this is hardly advisable, as 

 they cannot be made so fine as by burning and sla- 

 king. As was stated in the first section of this book, 

 lime usually exists in nature, in the form of carbo- 



