36 A PRACTICAL TREATISE 



the Board of Agriculture, in the treatise on manures which 

 gained him the Bedford ian medal of the Bath and West of 

 Eng-land Agricultural Society. Many who previously doubted 

 it have been since persuaded of its superiority by much practi- 

 cal as well as theoretical evidence then brought forward ; to 

 which there has been since added the powerful arguments of 

 Sir Humphry Davy, who thus expresses himself: — 



' Whoever will refer to the simplest principles of chemistry 

 cannot entertain a doubt on the subject. As soon as dung 

 begins to decompose, it throws off its volatile parts, which are 

 the most valuable and most efficient. Dung which has fer- 

 mented, so as to become a mere soft cohesive mass, has gene- 

 rally lost from one-third to one-half of its most useful con- 

 stituent elements ; and that it may exert its full action upon 

 the plant, and lose none of its nutritive powers, it should 

 evidently be applied much sooner, and long before decomposi- 

 tion has arrived at its ultimate results. 



' A slight incipient fermentation is undoubtedly of use in 

 the dung-hill, for by means of it a disposition is brought on in 

 the woody fibre to decay and dissolve when it is carried to the 

 land, or ploug-Jied into the soil, and woody fibre is always in 

 great excess in the refuse of the farm. Too great a degree 

 of fermentation is, however, very prejudicial' to the composite 

 manure in tlie dung-hill ; it is better that there should be no 

 fermentation at all before the manure is used than that it 

 should be carried too far ; for the excess of fermentation tends 

 to the destruction and dissipation of the most useful of its 

 parts, and the ultimate results of this process are like those of 

 combustion.' 



The sentiments of this celebrated chemist are certainly 

 entitled to great weight ; but though we admit that the fer- 

 mentation of farm-yard manure hiay be rendered injurious, 

 botli through the waste which occurs in bulk, as well as by 

 the loss of some portion of its nutritive properties, if that 

 process be carried to excess, yet we are inclined to doubt the 

 correctness of that position which says ' that it should be 

 applied long before decomposition has arrived at its ultimate 

 results.' We think also, that some distinction should be 

 drawn between the different kinds and qualities of dung, as 

 well as of the crops to which it is to be applied, and of the 

 season in which it is to be used, before any such un-exception- 

 able rule should be adopted for its preparation. Thus, to 

 recommend the application of fresh manure for a crop of 



