MANURES. 141 



3. It causes the mineral particles of the soil to 

 crumble. 



4. By producing the above effects, it prepares the 

 constituents of the soil for assimilation by plants. 



5. It is said to exhaust the soil ; but as it does so 

 through its beneficial action in producing larger 

 crops, and only in this way, it is only necessary to 

 return to the soil the other earthy ingredients that 

 the larger crops remove from it. 



1. The decomposition of organic matter in the soil, 

 especially if too wet, often produces acids which 

 make the land sour, and cause it to produce sorrel 

 and other weeds, and which interfere with the 

 healthy growth of crops. Lime is an alkali, and if 

 applied to soils suffering from sourness, it will unite 

 with the acids, and neutralize them, so that they will 

 no longer be injurious. 



2. We have before stated that lime is a decompo- 

 sing agent, and hastens the rotting of muck and 

 other organic matter. It has the same effect on the 

 organic parts of the soil, and causes them to be re- 

 solved into the gases and minerals of which they arc 

 formed. It has this effect, especially, on organic 

 matters containing nitrogen, causing them to pro- 

 duce ammonia ; consequently, it liberates this gas 

 from the animal manures in the soil. 



3. Yarious earthy compounds in the soil are so 

 affected by lime that they lose their power of holding 

 together, and crumble, or are reduced to finer par- 

 ticles, while some of their constituents are ren- 

 dered soluble. This crumbling effect improves the 



