38 A PRACTICAL TREATISE 



any soil to plough down effectually a large quantity of rank 

 strawy manure; tor even the stubbles, wlien cut high, are 

 found difficult to bury, and more especially on light land this 

 fresh stable-dung slides along the ground before the breast of 

 the plough, and thus clogs the furrow. Tlie harrows also 

 drag up considerable quantities, which not alone impede their 

 action, but a large portion of the manure is thus scattered 

 over the surface of the ground, and uselessly left there to 

 perish ; and litter that had been plouo-hed down fresh has, in 

 numerous instances, been turned up in the following spring 

 without any apparent change. Objections such as these are 

 not easily obviated, but even were they surmounted, the value 

 of the dung in that state of preparation still remains to be 

 considered. 



Of the mysteries of nature in her supply of food to plants 

 we have no certain information, and it is even probable that 

 they will ever elude discovery. Some experiments whicli 

 were made by Sir Humphry Davy, however, favoured tlie 

 opinion ' that soluble matters pass unaltered into the roots of 

 plants f in support of which he says — 'that the great object iii 

 the application of manure should be to make it afford as much 

 soluble matter as possible to the roots of the plants, and that 

 in a slow and gradual manner, so that it may be entirely con- 

 sumed in forming the sap of the organized plant ;' in order to 

 attain which effect, he admits ' that it must undergo chemical 

 changes.'' Now, the materials of which the great bulk of 

 farm-yard manure is composed, consist chiefly of straw or 

 other litter, which, being fibrous, can only be rendered soluble 

 by fermentation : but chemical theorists assert that this process 

 should be perfected at least, if not commenced, underground ; 

 for they msist that, if completed in the dung-hill, it would 

 occasion a great loss of nutritive matter; and it must be 

 admitted that several practical men of considerable judgment 

 have become converts to the same notion. Thus, one of the 

 latter body says — 'that, although half- rotted manure will 

 sooner disappear in the soil, and that the crop sown along 

 with it may often be better than on fresh dung improperly 

 applied, there may be little doubt; but there can be as little 

 that, during the time the latter is visible, it has afibrded the 

 greatest share of nourishment;' and he then asserts, 'that the 

 ravages of fermentation and exhalation are more to be dreaded, 

 and ought to be more guarded against, than any other waste 

 to which a heap of dung is liable.' 



