PROPERTIES OF MANURES 239 



the surface of uncropped ground, at the rate of 

 half a bushel to a rod, a space of ground measuring 

 5^ yards each, if in a square. It is a splendid 

 sweetener to soil that has been overfed with 

 stable manure, and is also good for all stone 

 fruit." 



Lime acts as a direct plant- food ; it renders the 

 inert constituents of the soil readily available ; it 

 neutralises the acidity of boggy, peaty and or- 

 ganic soils ; it hastens nitrification ; it liberates 

 soluble potash from the insoluble minerals present 

 in soils ; it renders heavy lands more friable, and 

 therefore facilitates digging ; it renders sandy soils 

 less porous (a property of great value in dry 

 summers), and it destroys many vegetable and 

 animal foes in the soil. 



Lime should never be used with sulphate of 

 ammonia or similar compounds of, or bodies con- 

 taining, ammonia. 



Gypsum or sulphate of lime is used in certain 

 special manures ; and is present (as a drier) in 

 superphosphate of lime. It aids in the formation 

 of albuminoids in plants ; it fixes ammonia in the 

 soil, and it liberates potash from insoluble minerals 

 of the soil. 



Magnesium Sulphate (sulphate of magnesia) 

 is a valuable manure, and it enters into the com- 



