Book III. MANAGEMENT OF MANURES. 341 



he comes into the stable, he sweeps whatever excrement may be found under the 

 cattle into the trench, which may be emptied as often as the liquid it contains is found 

 to be of a due thickness. The best proportion of the mixture is three fourths of water to 

 one fourth of excrement, if the cattle be fed on corn ; if in a course of fattening, one fifth 

 of excrement to four fifths of water will be sufficient. [Bull, du Comite d'Agri. dc 

 la Soc des Arts de Geneve.) This mode of increasing the manure produced by stalled 

 cattle and cows is in general use in Holland and the Netherlands; and we have seen 

 it practised in Fiance at Trappe and Grignion near Versailles, at Roville near Nancy, at 

 Ebersberg, and Schleissheim near Munich, and at Hohenheim and Weil near Stuttgard. 

 We would strongly recommend the practice to the British farmer, and not to the farmer 

 only, but to every cottager who keeps a cow or pig ; nay, to the cottager who is without 

 these comforts, but who has a garden, in which he could turn the great accession of 

 manure so acquired to due account. Let him sink five tubs or large earthen vessels in 

 the ground, and let the contents of the portable receiver of his water-closet, all the water 

 used for washing in the house, soap-suds, slops, and fermentable offals of every descrip- 

 tion during a week be carried, and poured into one of these tubs; and if not full on the 

 Saturday night, let it be filled up with water of any kind, well stirred up, the lid 

 replaced, and the whole left for a week. Begin on the Monday morning with another 

 tub, and when after five weeks the whole five are filled, empty the first at the roots 

 of a growing crop, and refill. Or use two larger tubs, and continue filling one for 

 a month ; then begin the other, and at the end of a month empty the first ; and so on. 

 (Gard. Mag. vol. v. p. 549.) 



Subsect. 3. Of the Fermenting, Preserving, and Ajwh/ing of Manures of Animal and 



Vegetable Origin. 



*2270. On the management of organic manures depends much of their value as food to 

 plants. The great mass of manures procured by the cultivator are a mixture of animal 

 and vegetable matters, and the great source of supply is the farm or stable-yard. Here 

 the excrementitious matter of horses, cattle, swine, and poultry, is mixed with straw, 

 haulm, chaff, and various kinds of litter. To what degree should this be fermented' 

 before it is applied to the soil ? and how can it best be preserved when not immediately 

 wanted ? 



2271. A slight incipient fermentation is undoubtedly of use in the dunghill; 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 ploughed into the soil ; and woody fibre is always in groat 

 excess in the refuse of the farm. Too great a degree of fermentation is, however, very 

 prejudicial to the composite manure in the dunghill : it is better that there should be no 

 fermentation at all before the manure is used, than that it should be carried too far. 

 The excess of fermentation tends to the destruction and dissipation of the most useful 

 part of the manure ; and the ultimate results of this process are like those of combus- 

 tion. It is a common practice amongst farmers to suffer the farm-yard dung to ferment 

 till the fibrous texture of the vegetable matter is entirely broken down ; and till the 

 manure becomes peifectly cold, and so soft as to be easily cut by the spade. Inde- 

 pendently of the general theoretical views unfavourable to this practice, founded upon 

 the nature and composition of vegetable substances, there are many arguments and facts 

 which show that it is prejudicial to the interests of the farmer. 



2272. During the violent fermentation which is necessary for reducing farm-yard 

 manure to the state in which it is called short muck, not only a large quantity of fluid, but 

 likewise of gaseous matter, is lost ; so much so, that the dung is reduced one half, or two 

 thirds in weight : the principal elastic matter disengaged is carbonic acid with some am- 

 monia ; and both these, if retained by the moisture in the soil, as has been stated before, 

 are capable of becoming a useful nourishment of plants. In October, 1808, Sir II. 

 Davy filled a large retort, capable of containing three pints of water, with some hot 

 fermenting manure, consisting principally of the litter and dung of cattle ; he adapted' 

 a small receiver to the retort, and connected the whole with a mercurial pneumatic 

 apparatus, so as to collect the condensible and elastic fluids which might rise from the 

 dung. The receiver soon became lined with dew, and drops began in a few hours to 

 trickle down the sides of it. Elastic fluid likewise was generated ; in three days thirty- 

 five cubical inches had been formed, which, when analysed, were found to contain 

 twenty-one cubical inches of carbonic acid; the remainder was hydrocarbonate mixed 

 with some azote, probably no more than existed in the common air in the receiver. The 

 fluid matter collected in the receiver at the same time amounted to nearly half an ounce ; 

 it had a saline taste and a disagreeable smell, and contained some acetate and carbonate 

 of ammonia. Finding such products given off from fermenting litter, he introduced 

 the beak of another retort, filled with similar dung, very hot at the time, into the soil 

 amongst the roots of some grass in the border of a garden. In less than a week a very, 

 distinct effect was produced on the grabs ; upon the spot e.\posed to the influence of the 



Z o 



