THE FARMER'S MAGAZINE. 



321 



and prevent the more decomposed materials from sink- 

 ing into the ground. The loaded carts are backed to 

 the extreme end of the site, on which the contents are 

 pulled, and formed loosely into a bank of about four 

 feet in width, that is raised to about six feet, and made 

 level on the top. Banks in succession are raised in 

 this way, the whole width of the site, sloping at the 

 sides, and level on the top. The contents are pulled 

 from the carts upon the bank, and spread most care- 

 fully over the surface, thinly and evenly, dry and moist 

 substances being mixed, where any necessity appears. 

 The loaded carts are backed close to the banks, which 

 facilitates the emptying of the contents in the proper 

 places. A confidential person, with assistance, is placed 

 on the banks, and entrusted with the construction and 

 management of the manure heap. The sides are neatly 

 sloped, and the fop made level, the wettest materials 

 being placed outside; and if much dried afterwards, 

 the outside and top of the heap are cut and dug over, 

 in order to procure a uniformity of quality. A light 

 covering of earth is thrown over the top of the heap, 

 and may be built up the sides, to prevent the drying 

 by the sun and winds. 



When any manures are purchased from towns and vil- 

 lages, as from butchers' stalls, pig-sties, cow-sheds, and 

 similar matters to farm-yard dung, the substances are 

 strewed in mixture evenly and thinly along the banks 

 of the manure-heap as raised in succession. Minute 

 earthy matters are not allowed, as the spreading in the 

 drills is inconvenient by the tools used for farm- yard 

 dung ; but all strawy and large fibrous substances are 

 best used in mixture with farm-yard dung in the heaps 

 as formed during winter. The quality of the heap is 

 greatly improved. 



The yards being empty of the contents in January, 

 will be again filled in the end of March, when the dung 

 is carried to the heaps in the field, and treated as has 

 been described, by being added to the made heaps of 

 January, or made into new formations where required. 

 After March, farm-yard dung is not advantageously 

 prepared, or at furthest into the middle of April : after 

 that time the contents of the yards lie over summer for 

 autumn use. 



It is very advantageous that heaps of farm-yard 

 dung are constructed during wet weather which admits 

 the possibility of working under it, and also during 

 snowy weather, and all for the inestimable privilege 

 of a large moisture being supplied to the heap of mLxed 

 substances. Experience has shown the benefit of lay- 

 ing upon the heap a large covering of snow, which dis- 

 solves, and sinks gradually into the heap beneath, with 

 a store of ammonia and moisture : rain-water and 

 snow-water convey this beneficial element. A cool 

 sheltered situation is advantageous to a heap of farm- 

 yard dung. 



In the state of loose aggregation and light treading 

 of heaps, as has been described, farm-yard dung com- 

 mences a fermentation that is more or less rapid and 

 violent as the circumstances of weather and ingredients 

 of composition will encourage and permit. The free 

 admission and contact of air, and a certain degree of 



heat from the changes of weather, will advance the fer- 

 menting process which arises from the action of the 

 difierent substances on each other, by which intestine 

 commotions a spontaneous reaction of the constituent 

 elements goes on, and a series of changes of composi- 

 tions terminate in the formation of new products, essen- 

 tially different from the original substances. The 

 elastic fluids evolved from vegetables are combinations 

 of the elements of the plants, and have for their bases 

 carbon and hydrogen. Animal matters evolve, during 

 putrefaction, much ammonia, and products peculiar to 

 themselves, particularly combinations of sulphur and 

 phosphorus, and hence the foetid odours and noxious 

 properties of the gases extricated from them. During 

 the decomposition of mixed animal and vegetable sub- 

 stances, heat is generated and disengaged by the ab- 

 sorption of oxygen or vital air, and water is decom- 

 posed. As putrefaction advances, ammonia or volatile 

 alkali is formed, and in its tendency to escape from the 

 heap it unites with such of the vegetable matters of the 

 dung as have advanced to the oxygenated state, and 

 forms a saline saponaceous substance, so very condu- 

 cive to the growth of plants. Fermentation goes on in 

 moisture and heat at 55 to GO deg. : oxygen is absorbed 

 and carbonic acid formed, heat is produced, and elastic 

 fluids, chiefly carbonic acid, gaseous oxide of carbon, 

 and hjdro-carbonate are evolved : a dark-coloured 

 liquid of a sour and bitter tasto will be formed, and 

 leaves ultimately earthy and saline matter, coloured 

 black by charcoal : the fluid always contains acetic 

 acid, and when albumen or gluten exists in the vege- 

 tables, it contains volatile alkali. The elastic fluids are 

 carbonic acid principally; the condensable are the 

 acetate and carbonate of ammonia. Fermentation is 

 divided into three stages — the vinous, or sweet ; the 

 acetous, or acid ; and the putrefactive, or the rotteti. 

 The first two are confined to saccharine plants : the last 

 comprehends a wider range, and includes almost every 

 animal and vegetable. The three stages are not always 

 necessary : the acetous takes place without the vinous, 

 and the putrefactive without either. Farm-yard dung 

 undergoes the last two processes. 



In most cases of lightly-trodden heaps of farm-yard 

 dung that has been prepared in the yards and placed 

 in masses, as has been described, the first stage of de- 

 composition has been passed, and the heap has ad- 

 vanced into the state of putrefaction (and which exists 

 not beyond the middle process) by the time when the 

 dung is applied to the land in the end of May and du- 

 ring the month of June. The mass will appear in a 

 soapy consistence, damp, and soft, and not wholly de- 

 void of heat, but retaining that element in some con- 

 siderable degree. The later formations of heaps in 

 March and April will not be so far advanced in the 

 fermentation, retain more warmth, and exhalations 

 will arise from the movement of the dung. The first 

 process has not ceased, and the putrefaction has not 

 extinguished the internal commotions. In order to 

 retain the elastic fluids that escape during fermentation, 

 a covering of earth is laid over the heap of dung, and 

 [ a cohering of gypsum over the eai'th, as this last sub- 



