Heiden (Storer's Agriculture) states that for each 100 lb. of dry matter which the horse consumes, he gives off 210 lb. of dung and urine. An ordinary cart horse will produce about 1/2 cwt. of dung and urine in twenty-four hours. The quantity of manure obtained in a stable from the dung, urine, and soiled bedding varies according to the amount of food and bedding, and according to the length of time the horse is in the stable. Mr. Porch, F.R.C.V.S., who is in charge of the London Road Car Company's horses, tells me that the weekly quantity of manure produced by each of these animals, averages from 2 1/2 to 3 cwt. a week. They have a daily ration of 31 lb. of corn and hay, a weekly allowance of 38 lb. of peat moss bedding (costing 7 1/2 d. a week), and are absent from their stables about three hours out of the twenty-four. When horses are away from their stables for seven or eight hours each day, they will, as a rule, deposit more dung outside, than in the stable; although the opposite of this will be the case with the urine. A friend of mine who has had a large experience among cart horses, puts the average quantity of manure for each horse at about 2 1/2 cwt.

Muntz and Lavalard have shown that manure resulting from the use of peat moss is of from 15 to 30 per cent. higher agricultural value than that of straw, a fact which is principally due to the great absorbent power for fluids (urine) and gases (ammonia) possessed by peat moss. The manure from peat moss is specially applicable to the cultivation of potatoes and roots, and as a manure for heavy clay land. Straw stable manure suits light (sandy) land. Sawdust and shavings have, as manure, the great disadvantage of taking a long time to rot.

As straw has but little power of retaining ammonia, which is a very valuable constituent of manure, we should try, for purposes of economy, to prevent this loss as far as possible. "The addition of earth (not sand or chalk) to straw considerably increases its power of retaining ammonia. Sprinkling powdered gypsum, superphosphate, or kainite also diminishes the loss of ammonia. . . . Farmyard manure rapidly undergoes fermentation. If placed in a heap, the mass gets very hot, and a large quantity of carbonic acid and some marsh gas are given off. Fermentation is most active when the manure lies loosely, more air then coming in contact with it; it is least active when the manure heap is consolidated. When fermentation occurs in consolidated, wet manure, in a place protected from rain, a considerable part of the carbonaceous matter is destroyed, but comparatively little loss of nitrogen takes place; if, however, the manure gets dry, and mould appears, a serious loss of free nitrogen may occur. The losses of nitrogen in the heap may be prevented by introducing a shallow layer of earth each day while the heap is in construction.

"Rotten manure, when well made, is more concentrated than the fresh, having greatly diminished in weight during fermentation without a corresponding loss of valuable constituents. Some of the constituents have also become more soluble. It is often, however, best to cart the fresh manure directly on to the land, and plough it in. Loss in the heap is thus prevented, and the full physical benefits of the manure obtained. Manure heaps in the open field should be protected from waste by covering them with a layer of earth 6 inches thick" (Warington's Chemistry of the Farm).

The British Moss Litter Company give the following directions for converting peat which has been used in a stable, into good manure: "The moss litter after use as bedding should be made into a heap and saturated with liquid manure or water until it will hold no more; then make level on the top and cover up with fine ashes or earth. In about two months it will be quite black and rotten and fit to go on to the land."

Before stable manure can be utilised as a food by plants, a large proportion of its nutritive material has to undergo decomposition by means of bacteria, which convert more or less of its constituents into soluble compounds, and thus perform the office of digestion for the plants. Oxidation, which in this case is a process of destruction, also takes place in manure, especially when the manure is in a loose and dry condition. The heat produced by oxidation is liable to become so great as to kill the microbes which are engaged in preparing the manure for the plants. Hence the advisability of keeping the manure damp and consolidated during its preparative ("rotting") period, or of mixing it with earth, which will keep its particles cool and moist, and will absorb the ammonia that is evolved.