Book III. SPECIES OF MANURES. 337 



2244. Manures from animal substances, in general, require no chemical preparation to 

 fit them for the soil. The great object of the fanner is to blend them with the earthy 

 constituents in a proper state of division, and to prevent their too rapid decomposition. 



2245. The entire parts of the muscles of land animals are not commonly used as manure, 

 though there are many cases in which such an application might be easily made. Horses, 

 dogs, sheep, deer, and other quadrupeds that have died accidentally or of disease, after 

 their skins are separated, are often suffered to remain exposed to the air, or immersed in 

 water till they are destroyed by birds or beasts of prey, or entirely decomposed ; and, in 

 tliis case, most of their organised matter is lost for the land in which they lie, and a con- 

 siderable portion of it employed in giving oft" noxious gases to the atmosphere. By 

 covering dead animals with five or six times their bulk of soil, mixed with one part of 

 lime, and suffering them to remain for a few months, their decomposition would im- 

 pregnate the soil with soluble matter, so as to render it an excellent manure ; and by 

 mixing a little fresh quicklime with it at the time of its removal, the disagreeable effluvia 

 would be in a great measure destroyed, and it might be applied to crops in the same way 

 as any other manure. 



2246. Fish forms a powerful manure, in whatever state it is applied ; but it cannot be 

 ploughed in too fresh, though the quantity should be limited. A. Young records an 

 experiment, in which herrings spread over a field, and ploughed in for wheat, produced 

 so rank a crop, that it was entirely laid before harvest. The refuse pilchards in Corn- 

 wall are used throughout the county as a manure, with excellent effects. They are 

 usually mixed with sand or soil, and sometimes with sea weed, to prevent them from 

 raising too luxuriant a crop. The effects are perceived for several years. In the fens 

 of Lincolnshire, Cambridgeshire, and Norfolk, the little fishes called sticklebacks are 

 caught in the shallow waters in such quantities, that they form a great article of manure 

 in the land bordering on the fens. It is easy to explain the operation of fish as a ma- 

 nure. The skin is principally gelatine, which, from its slight state of cohesion, is readily 

 soluble in water ; fat or oil is always found in fishes, either under the skin or in some of 

 the viscera ; and their fibrous matter contains all the essential elements of vegetable 

 substances. 



2247. Amongst oily substances, blubber has been employed as a manure. It is most 

 useful when mixed with clay, sand, or any common soil, so as to expose a large surface 

 to the air, the oxygen of which produces soluble matter from it. Lord Somerville used 

 blubber with great success at his farm in Surrey. It was made into a heap with soil, 

 and retained its powers of fertilising for several successive years. The carbon and 

 hydrogen abounding in oily substances fully account for their effects ; and their dura- 

 bility is easily explained from the gradual manner in which they change by the action ot 

 air and water. 



2248. Bones are much used as a manure in various parts of England, and especially 

 in Lincolnshire and Yorkshire. They are also used in Scotland wherever they can be 

 got, and a knowledge of their great value is spreading rapidly over the Continent. After 

 being broken, and boiled for grease, they are sold to the farmer. The more divided they 

 are, the more powerful are their effects. The expense of grinding them in a mill is 

 amply repaid by the increase of their fertilising powers ; and in the state of powder 

 they are used in the drill husbandry, and delivered with the seed in the same 

 manner as rape-cake. Bone-dust and bone-shavings, the refuse of the turning manu- 

 facture, may be advantageously employed in the same way. The basis of bone is con- 

 stituted by earthy salts, principally phosphate of lime, with some carbonate of lime and 

 phosphate of magnesia ; the easily decomposable substances in bone are fat, gelatine, 

 and cartilage, which seems of the same nature as coagulated albumen. According to 

 the analysis of Fourcroy and Vauquelin, ox-bones are composed of decomposable animal 

 matter 51, phosphate of lime 37"7, carbonate of lime 10, phosphate of magnesia 1-3; 

 total 100. To apply bone manure with effect, it is essential that the soil be dry. 



2249. Horn is a still more powerful manure than bone, as it contains a larger quantity 

 cf decomposable animal matter. From 500 grains of ox-horn, Hatchett obtained only 

 1 -5 grains of earthy residuum, and not quite half of this was phosphate of lime. The 

 shavings or turnings of horn form an excellent manure, though they are not sufficiently 

 abundant to be in common use. The animal matter in them seems to be of the nature 

 of coagulated albumen, and it is slowly rendered soluble by the action of water. The 

 earthy matter in horn, and still more that in bones, prevents the too rapid decomposition 

 of the animal matter, and renders it very durable in its effects. 



2250 Hair, woollen rags, and feathers, are all analogous in composition, and princi- 

 pally consist of a substance similar to albumen united to gelatine. This is shown by the 

 ingenious researches of Hatchett. The theory of their operation is similar to that of 

 bone and horn shavings. 



2251. The refuse of the different manufactures of skin ayid leather forms very useful 

 manures; such as currier's shavings, furrier's clippings, and the offals of the tan-yard 



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