82 A PRACTICAL TREATISE 



Considerable judg-ment is however requisite in this mode of 

 its application ; for, althoug-h it promotes putrefaction, and con- 

 verts the pulp, or saponaceous substance, of vegetable matter 

 into the food of plants, yet, if too great a portion of lime be 

 added, it may have a contrary effect; and it always destroys, 

 to a certain extent, the efficacy of animal manures, either by 

 combining with certain of their elements, or by giving to them 

 some new arrangement. It is necessary to the reduction of 

 carrion, or for qualifying the noxious effluvia of night-soil ; but 

 is so injurious when mixed with any common dung, that it 

 tends to render the extractive matter insoluble : thus, if a suf- 

 ficent quantity of quicklime be added to a heap of stable-dung 

 in a state of fermentation, it will set it on fire, and the whole 

 will be consumed. It should never, therefore, be mixed with 

 farm-yard manure, unless a small quantity be found absolutely 

 necessary for the prompt destruction of seed-weeds, or the de- 

 composition of roots; but when laid upon the land during the 

 same season, the dung should be ploughed down alone, and 

 the lime afterwards harrowed in with the seed-furrow. It 

 may, indeed, be observed, that the dung dropped from horses 

 in their work about kilns is usually so completely destroyed 

 by the lime which falls from the carts in filling, that it is 

 generally found useless to apply it to the land. It also con- 

 sumes the growing herbage; but, if prudently used, it does 

 not appear to reach the roots, as a fresh verdure soon after 

 arises, and seeds which had previously lain dormant in the soil 

 are brought into action.* 



By neutralizing the acids combined with the mould, this 

 manure qualifies the vegetable and other soluble substances 

 also present in it, and occasions the whole to be converted, by 

 the influence of the atmosphere and of water, into nutriment 

 for plants; but in poor soils, having less vegetable matter to . 

 convert into mucilage, it acts so powerfully as not only to ex- 

 haust such land by its final effects, but to be prejudicial to the 



*A circumstance has been related of mild and quicklime having been 

 separately laid upon land, with the follovving effect :— the spot upon which the 

 former was laid was soon covered with white clover, but on that on which the 

 latter was left, no vegetation w'hatever took place for a considerable time, 

 when it at length produced couch-grass, which is accounted for by the hot 

 lime having retained its causticity so long as to have entirely destroyed the 

 seeds of the clover, which are generally ditfused in calcareous soils, and 

 consequently flourish through the application of mild lime; while those of 

 the couch were either more difficult to eradicate, or wefe spread from the 

 adjoining land.— Sinclair's Code of Agric, 3d edit., note p. 235. 



