MANURES. 59 



The elementary parts of these manures, as ex- 

 hibited in this table, sufficiently indicate the mode 

 of preserving them. When dropped in the fields and 

 in small parcels by cattle, they exhibit no signs of 

 fermentation, nor undergo, in that state, any degree 

 of chymical decomposition ; but, when brought to- 

 gether, and frequently wetted and subjected to the 

 action of atmospheric air, they are speedily dis- 

 solved and give out much gaseous matter. To pre- 

 vent the escape of these soluble and volatile parts, 

 two things are necessary : 1st, that the dung be col- 

 lected in a reservoir of convenient size, and walled 

 and paved with stones ; and, 2d, that a layer of sand 

 or earth be occasionally spread over the surface of 

 the dung. The former will prevent filtration, and 

 the latter retain the gaseous matter so useful in 

 vegetation, and, at the same time, augment the quan- 

 tity of manure. To prevent an excess of moisture, 

 which always retards, and sometimes prevents de- 

 composition altogether, the reservoir should be 

 covered. 



The application of manures is a subject of more 

 difficulty, and has given occasion to some dispute. 

 The controverted points are, 



1st. Whether short or long dung, or, in other 

 words, whether dung thoroughly rotted, or that 

 which has but begun to rot, is most advantageous. 



2d. Whether dung used superficially, or ploughed 

 deep into the ground, is most profitable. 



3d. Whether extraneous matters admitted into 

 the dungheap are useful or otherwise. 



4th. Whether stable manures are best applied di- 

 rectly or indirectly to wheat crops. 



5th. At what time manures are best applied ; and, 



6th. In what quantity. 



We shall discuss these points separately and 

 briefly; and, 



1st. Which is to be preferred, long or short dung ? 



The discordance in practice, as well as in opinion, 



