85
atiy of them are so abundant as to make a conspicuous figure,and there is no report relating to the application of them as ma-nure.
Horns and hoofs of animals, however, are a substance of apeculiar conformation. This has been used as manure, and es-teemed a valuable one. Shavings of horn from places wherethat article is manufactured at home, and quantities importedfrom Irelanc, are spread on the land at the rate of about 60 stonesper acre. They are strewed on the ground by hand either ongrass or fallow, and have been found to occasion a considerableincrease of fertility. The effect is most evident where the soil isnot of the poorest quality, and has been distinguishable for seve-ral years. It has been remarked that where this substance is ap-plied, no moles burrow.
The bones and skins of animals, differ also in their conforma-tion from most other animal substances. The former is recom-mended by the celebrated Mr Kirwan as an appropriate manurefor wheat, but scar'cely used in Scotland . It is believed that af-ter the oil and mucilage they contain are exhausted, they can beof little use, as the combination of the principles of which theyare chiefly formed, resists decomposition for a very long period.The latter is also a compound not soon decomposed. Pieces ofuseless skins, and parings of tanned leather, are sometimes laid onland, with what effect there is no report: but as they may be seenremaining in the ground a long time after, it is probably neithergreat nor sudden.
Scarce any of the substances above enumerated and describedare homogeneous bodies; and the substance denominated Dungis the most complicated of all. Yet husbandmen have been inthe constant practice of mixing several of them with one another,before applying them to the soil. These mixtures are called Com-post, and consist of various ingredients.
The first kind of composts of which there are any accounts,was soil covered with a close sward of herbage, found by thesides of roads, brooks, or waste corners, which had lain long ne-glected, (often called virgin earth ), mixed with lime and freshfarm dung. A base of the earth was first formed, over which acoat of dung was laid ; a layer of earth succeeded; then limeeither in shells or powder, which was again covered with earth ;and so on alternately, a layer of earth always intervening be-tween each of the other substances, till the heap was raised tothe height of 4 or 5 feet, the top being covered with earth. Thiswas afterwards cut in pieces with spades, turned and mixed, andperhaps turned again and again, till it was thought fit to be car-tied out and spread on the ground. Either lime or dung wassometimes used without the other. The swarded borders of peatmosses are sometimes used in place of mould. A more compen-
¥ 2