340 SCIENCE OF AGRICULTURE. Part II. 



2262. Rabbits^ dung has never been analysed. It is used with great success as a 

 manure by some farmers, who find it profitable to keep rabbits in such a manner as to 

 preserve their dung. It is laid on as fresh as possible, and is found better the less 

 it has fermented. 



2263. The dung of cattle, oxen, and cows has been chemically examined by Einhof 

 and Thaer. They found that it contained matter soluble in water ; and that it gave in 

 fermentation nearly the same products as vegetable substances, absorbing oxygen, and 

 producing carbonic acid gas. 



2264. The recent dung of sheep and of deer affords, when long boiled in water, soluble 

 matters which equal from two to three per cent of their weight. These soluble sub- 

 stances, procured by solution and evaporation, when examined, contain a very small 

 quantity of matter analogous to animal mucus ; and are principally composed of a bitter 

 extract, soluble both in water and in alcohol. They give ammoniacal fumes by distil- 

 lation, and appear to differ very little in composition. Some blades of grass were 

 watered for several successive days with a solution of these extracts ; they evidently 

 became greener in consequence, and grew more vigorously than grass in other respects 

 under the same circumstances. The part of the dung of cattle, sheep, and deer, not 

 soluble in water, appears to be mere woody fibre, and precisely analogous to the residuum 

 of those vegetables that form their food after they have been deprived of all their soluble 

 materials. 



2265. The dung of horses gives a brown fluid, and this, when evaporated, yields a bitter 

 extract, which affords ammoniacal fumes more copiously than that from the dung of 

 oxen. 



2266. In the treatment of the pure dung of cattle, sheep, and horses, there seems no 

 reason why it should be made to ferment except in the soil, like the other pure dungs ; 

 or, if suffered to ferment, it should be only in a very slight degree. The grass, in the 

 neighbourhood of recently voided dung, is always coarse and dark green ; some persons 

 have attributed this to a noxious quality in unfermenting dung ; but it seems to be rather 

 the result of an excess of food furnished to the plants. 



2267. Street and road dung and the sweepings of houses may be all regarded as com- 

 posite manures ; the constitution of them is necessarily various, as they are derived from 

 a number of different substances. These manures are usually applied without being 

 fermented. 



2268. Soot, which is principally formed from the combustion of pit-coal or coal gene- 

 rally, contains likewise substances derived from animal matters. This is a very powerful 

 manure. It affords ammoniacal salts by distillation, and yields a brown extract to hot 

 water, of a bitter taste. It likewise contains an empyreumatic oil. Its great basis is 

 charcoal, in a state in which it is capable of being rendered soluble by the action of 

 oxygen and water. This manure is well fitted to be used in the dry state thrown into 

 the ground with the seed, and requires no preparation. 



2269. Liquid Manure. The farmers of German Switzerland give the name of guile, in 

 French lizier, to the liquid manure obtained from their stalls and stables, and collected 

 into underground pits or reservoirs, in which it is allowed to ferment in a mucous or slimy 

 state. The manner of collecting it adopted by the agriculturists of Zurich is as follows : 

 The floor on which the cattle are stalled is formed of boards, with an inclination of four 

 inches from the head to the hinder part of the animal, whose excrements fall into a 

 gutter behind, in the manner usual in English cow-houses : the depth of this gutter is 

 15 inches, its width 10 inches. It should be so formed as to be capable of receiving, at 

 pleasure, water to be supplied by a reservoir near it ; it communicates with five pits by 

 holes, which are opened for the passage of the slime, or closed as occasion requires. The 

 pits or reservoirs of manure are covered over with a floor of boarding, placed a little 

 below that- on which the animals stand. This covering is important as facilitating the 

 ferme^lation. The pits or reservoirs are made in masonry, well cemented, and should be 

 bottomed in clay, well beaten, in order to avoid infiltration. They should be five, in 

 order that the liquid may not be disturbed during the fermentation, which lasts about four 

 weeks. Their dimensions should be calculated according to the number of animals the 

 stable holds, so that each may be filled in a week. But whether full or not, the pit must 

 be closed at the week's end, in order to maintain the regularity of the system of empty- 

 ing. The reservoirs are emptied by means of portable pumps. In the evening the 

 keeper of the stables lets a proper quantity of water into the gutter ; and on returning to 

 the stable in the morning, he carefully mixes with the water the excrement that has fallen 

 into it, breaking up the more compact parts, so as to form of the whole an equal and 

 flowing liquid. On the perfect manner in which this process is performed the quality of 

 the manure mainly depends. The liquid ought neither to be thick, for then the ferment- 

 ation would be difficult ; nor too thin, for in that case it would not contain sufficient 

 nutritive matter. When the mixture is made, it is allowed to run off into the pit beneath, 

 and the stable-keeper again lets water into the trench. During the day, whenever 



