The manure. An average statement of that composition is therefore very much more difficult to obtain. number of analyses available for the purpose of forming this average is, however, very large. The manure produced by cows contains a large percentage of water. This is due to the large quantity of water they drink. It has been estimated that milk-cows drink along with their winter food, for every pound of dry substance, 4 lb. of water, and in summer about 6 lb. According to some experiments by Boussingault, the excrements of a cow in a day amounted to 73.23 lb., of which only 9.92 lb. were dry matter.1 These excrements contained .256 lb. of nitrogen, and 1.725 lb. of mineral matter. The amount of straw necessary to use as litter for this amount of excrements may be taken at 6 to 10 lb. The manure, therefore, formed by a cow per day would contain from .274 to .286 lb. of nitrogen, and from 2.046 to 2.278 lb. of mineral matter. In a year this would amount to from 100 to 104.4 lb. of nitrogen, and from 746.8 lb. to 831.5 lb. of mineral matter; or from 6 cwt. 75 lb. to 7 cwt. 47 lb. Cowdung is, owing to its much more watery nature and poorer quality, very much slower in its fermentation than horse-dung. When applied alone cow-manure is very slow in its action, and makes its influence felt for at least three or four years. It is difficult to spread it evenly over the soil, owing to the fact that, 1 The food consisted of 30 lb. potatoes, 15 lb. hay, and 120 lb. water. when somewhat dried, it has a tendency to form hard masses, which, when buried in the soil, may resist decomposition for a very long period. The cause of this is due to the presence of a considerable amount of mucilaginous and resinous matter in the solid excreta, which prevent the entrance of moisture and air into the centre of the mass. This tendency of cowmanure to resist decomposition will be greatly lessened in the case of the excrements of a cow richly fed. The risks of loss of volatile ammonia are, therefore, in its case not so great as we have seen them to be in the case of the "hot" horse-dung. Notwithstanding this fact, much of what has been said. on the use of preservatives for horse-manure may be also applied to the cow-dung. This is owing to the fact that the dung is allowed to accumulate in the court for some time. The amount of straw it is advisable to use as litter varies, as has been said, from 6 to 10 lb. per day. The best method of calculating this amount, according to Dr Heiden, is by taking onethird of the total weight of the dry substance of the food. The above authority also recommends that the straw is best applied in blocks of about one foot in length; and this for the following reasons: 1. The strewing of it is more convenient. 2. The absorption of the fluid portion is more complete. 3. The cleaning out of the manure from the byre is easier. 4. The manure is more easily distributed when applied to the field. Among the advantages incidental to allowing the manure to accumulate in the court may be mentioned the following: 1. The more thorough absorption of the urine by the straw, and, consequently, the more uniform mixture which will be thus effected of the more valuable urine with the less valuable solid excreta. 2. A certain retardation of decomposition effected by the treading under foot of the manure. 3. The protection of the manure from rain and wind, and the securing of a uniform temperature. Against those advantages must be placed the risk of seriously affecting the health of the animal. Although this is a point of very great importance, it scarcely falls within the scope of this work. It may be pointed out, however, that the judicious use of some of the chemical fixers previously referred to may do much to keep the air of the byre or court free of noxious gases.1 3. Pig-manure.-The food of the pig is so very variable in its character, that it is wellnigh impossible to obtain anything like an average analysis of its excrements. When the food of the pig is rich, then the manure may be quite equal in quality to the other manures. According to Boussingault, the total amount of excrements, on an average, voided by a pig in twentyfour hours is about 8.32 lb., of which 1.5 lb. is dry 1 For further analyses of cow-manure, see Appendix, Note XI., p. 60. matter.1 The amount of nitrogen these excrements contain is only .05 lb., and of mineral ingredients .313 lb. If we take the amount of straw, most suitable for absorbing this quantity of excrementitious matter, at from 4 to 8 lb., then we shall find that the manure produced by a pig will contain from .06 to .074 lb. nitrogen, and .545 to .772 lb. mineral matter. These quantities, calculated for a year, give from 22 to 27 lb. of nitrogen, and from 1 cwt. 87 lb. to 2 cwt. 57 lb. of mineral matter. That is about as much nitrogen as would be contained in 14 to 1 cwt. of nitrate of soda (95 per cent purity); or from slightly less than 1 cwt. to slightly over 1 cwt. of sulphate of ammonia (97 per cent purity). As has already been pointed out, the excrements of the pig are, as a rule, very poor in nitrogen. This accounts for the fact that pig-manure is a cold " manure, slow in fermenting. 4. Sheep-manure.-The dung and the urine of the sheep, as we have already seen, are, weight for weight, the most valuable of any of the common farm animals. The total weight of the excrements voided by a sheep in a day may be taken, on an average,2 at 3.78 lb., of which .97 lb. is dry matter. These excrements contain .038 lb. of nitrogen and .223 lb. mineral matter. Taking the amount of straw most suitable for absorbing 1 This is for a pig of 6 to 8 months old, and fed on potatoes. 2 Taken from a very large number of analyses by a number of experimenters. See Heiden's Düngerlehre, vol. i. p. 99. this quantity of excrementitious matter at three-fifths of a pound, then the manure produced by a sheep in a day will contain .0429 lb. nitrogen, and .264 lb. mineral matter. That is, in a year the quantities of nitrogen and mineral matter in the manure produced by a sheep would be 15.66 lb. of nitrogen and 96.36 lb. of mineral matter. From its richness in nitrogen, and from its dry condition, sheep-dung is peculiarly liable to ferment. While richer in fertilising substances than horse-manure, it is not so rapid in its fermentation. This is due to the harder and more compact physical character of the solid excreta. The risks of loss of volatile ammonia are, in its case, exceptionally great. The use of artificial "fixers" is therefore to be strongly recommended.1 1 See Storer, Agricultural Chemistry, vol. ii. p. 96. A question of great importance is as to the amount of farmyard manure produced on a farm in a year, and its value. This is a question which is extremely difficult to satisfactorily deal with. Various methods of calculating this amount have been resorted to. It may be well to state these pretty fully. Some practical authorities estimate the amount by calculating that every ton of straw should produce 4 tons of manure. Another method consists in estimating the amount from the size of the farm. "It is not very wide of the mark to say that the weight of manure produced by consuming with stock in the yards an acre of turnip crop will be 6 tons, and that an acre of green clover similarly fed will give 5 tons of manure; an acre of pasture, 5 tons; an acre of wheat-straw, 4 tons; and an acre of barley or oat straw, 4 tons. One hundred acres of good arable land will produce in a year about 5 tons per acre, or 500 tons" (Professor Scott). Another method is by taking, as the data of calculation, the number of cattle, horses, sheep, &c., producing the manure. Lloyd considers that a fattening animal requires 3 tons of straw in the |