MANURES. 61 



ficially, the rains dissolve and carry away many of 

 its juices, while the sun and the wind evaporate the 

 rest. These considerations lead to the true rule on 

 this head, which is to lay it three or four inches be- 

 low the surface of the soil. At this depth, if short 

 dung, its action will be most vigorous in all direc- 

 tions ; and if long dung, a greater depth will, as al- 

 ready suggested, completely destroy all action. 



3d. Are extraneous matters, as horns, hoofs, 

 bones, shells, feathers, leaves, weeds, &c., &c., to 

 be admitted into the dung-heap ? 



There is, perhaps, nothing in either theory or 

 practice so obviously right, that it may not be dis- 

 puted. The principal objection made to these mat- 

 ters is, that they do not decompose equally ; and 

 that those ingredients of the heap which are slow- 

 est in decomposition, retard others, which, if left to 

 themselves, would be more forward in this process. 

 This objection is without weight ; for we have seen 

 that long or unrotted manure, though its effect be 

 prompt, is, upon the whole, more favourable to cul- 

 ture than that which is rotted. The difference 'of 

 time in decomposition is therefore no evil, and the 

 augmentation of the mass is a great good ; besides 

 that, some of these offals are the most powerful 

 manures. Horns and hoofs are compounded of al- 

 bumen and gelatine ; bones, of the phosphate and 

 carbonate of lime and gelatine ; shells, of carbonate 

 of lime and animal matter ; and feathers and hair, 

 of albumen, oil, &c., &c. Applied to the roots, they 

 forward the growth of fruit-trees more than any 

 other species of manure. 



4th. Whether stable manures are best applied, 

 directly or indirectly, to wheat crops 1 



The practice, on this head, is different in different 

 places. In France, as in all other countries where 

 fallows are in use, the dung is applied directly to 

 the wheat crop ; while in England, where the rota- 

 tion system is established, it is applied to the sum- 

 F 



