39 



turn is necessary to convert the nitrogen into nitric 

 acid and ammonia. 



But let us have patience, there never was a pile 

 of hay, or grain or grass, that would not rot down, 

 and in reasonable time, make manure. 



But how shall we hasten this decay to the best 

 advantage ? 



By keeping 1 the material upon the surface. Dr. 

 Vcelcker discovered that hay or new mown grass lost 

 more than half of its richest elements, when left on 

 the field, and exposed to leaching rains for a short 

 time. 



Unless the soil is very lose and sandy, vegetable 

 matter will not decay when plowed in, as soon as it 

 will upon the surface. 



Combustion is a rapid condition of decay. And 

 the whole process of decay is a slow combustion. 

 In both cases a union of oxygen with carbon and 

 hydrogen. Cover your fire with ashes or earth, and 

 it will not burn as brightly as when uncovered. 

 Bury half rotten manure, or straw, or wood, so deep 

 that air will be entirely excluded, and no further 

 decay can take place. 



Stirring the soil promotes the slow burning (decay) 

 of the vegetable matter in the ground. A pile of 

 clover hay may Jay for years, apparently but little 

 changed by decomposition. But a careful examina- 

 tion will disclose the fact> that nearly all its valuable 

 constituents have been carried into the soil. The 

 shell remains, but the oyster has been extracted. 



Minute division favors oxidation A substance 

 dissolved by water, and deposited on the soil, has its 



