The controversy, too, which once so keenly existed, as to the state of fermentation in which dung should be used on the land, has now pretty well subsided. There is no doubt but that it cannot be applied more advantageously than in as fresh a state as possible, consistent with the attainment of a tolerably clean husbandry, and the destruction of the seeds of weeds, grubs, etc, which are always more or less present in farm-yard dung. These are the only evils to be apprefrom the desirable employment of this manure in the freshest state; for otherwise the loss of its most valuable constituents commences as soon as fermentation begins. This was long since demonstrated by Davy, whose experiments I have often seen repeated and varied. He says, "I 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. I 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 arise 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 analyzed were found to contain twenty-one cubical inches of carbonic acid; the remainder was hydro-carburet, 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, I introduced the beak of another retort filled with similar dung very hot at the time, in the soil amongst the roots of some grass in the border of a garden. In less than a week a very discernible effect was produced on the grass, upon the spot exposed to the influence of the matter disengaged in fermentation; it grew with much more luxuriance than the grass in any other part of the garden." - Lectures.

Nothing, indeed, appears at first sight so simple as the manufacture and collection of farm yard dung, and yet there are endless sources of error into which the cultivator is sure to fall, if he is not ever vigilant in their management. The late Mr. Francis Blake, in his valuable tract upon the management of farmyard manure, dwells upon several of these; he particularly condemns the practice of keeping the dung arising from different descriptions of animals in separate heaps or departments, and applying them to the land without intermixture. "It is customary," he adds, "to keep the fattening neat cattle in yards by themselves, and the manure thus produced is of good quality, because the excrement of such cattle is richer than that of lean ones. Fattening cattle are fed with oil cake, corn, Swedish turnips, or some other food, and the refuse and waste of such food thrown about the yard increases the value; it also attracts the pigs to the yard. These rout the straw and dung about in search of grains of corn, bits of Swedish turnips, and other food; by which means the manure in the yard becomes more intimately mixed, and is proportionally increased in value.

The feeding troughs and cribs in the yard should for obvious reasons be shifted frequently.

"The horse-dung," continues Blake, "is usually thrown out at the stable doors, and there accumulates in large heaps. It is sometimes spread a little about, but more generally not at all, unless where necessary for the convenience of ingress and egress, or perhaps to allow the water to drain away from the stable door. Horse-dung lying in heaps very soon ferments and heats to an excess, the centre of the heap is charred or burned to a dry white substance, provincially termed fire-fanged. Dung in this state loses from fifty to seventy-five per cent. of its value. The diligent and attentive farmer will guard against such profligate waste of property by never allowing the dung to accumulate in any considerable quantity at the stable doors. The dung from the feeding hog-sties should also be carted and spread about the store cattle yard in the same manner as the horse-dung.

"The heat produced by the fermentation of the dung of different animals has been made the subject of repeated experiment. When the temperature of the air was 4CP, that of common farmyard dung was 70°; a mixture of lime, dung, and earth, 55°; swine and fowl's dung, 85°." - Farmer's Magazine, Johnson's Fertilizers.

"The quality of farm-yard compost naturally varies with the food of the animals by which it is made; that from the cattle of the straw-yard is decidedly the poorest, that from those fed on oilcake, corn, or Swedes, the richest. Of stable dung, that from corn-fed horses is most powerful, from those subsisting on straw and hay the poorest; the difference between the fertilizing effects of the richest and the inferior farm-yard dung is much greater than is commonly believed; in' many instances the disparity exceeds one-half; thus that produced by cattle fed upon oil-cake is fully equal in value to double the quantity fed upon turnips. Hence the superior richness of the manure of fattening swine to that of pigs in a lean state, and the far superior strength of night-soil to any manure produced from merely vegetable food. Chemical examinations are hardly necessary to prove these facts. Every farmer who has had stall-fed cattle will testify to their truth; every cultivator will readily acknowledge the superiority of ' town-made,' that is, corn-produced stable dung, to that from horses fed only on hay and straw, and that night-soil is far superior in strength to either.

The relative quantities employed by the cultivator betray the same fact, for on the soils where he applies twenty loads of good farm-yard compost per acre, he spreads not half that quantity of night-soil. The drainage from all manures should be scrupulously preserved, for the liquid or soluble portion constitutes their richest portion. The escape of their gaseous products during decomposition should also be checked as much as possible, for they contain ammonia, carbonic acid, etc, all abounding in constituents valuable as .fertilizers." - Johnson's Farmer's En-cyclop.