ON BONES, &c. AS MANURE.
Reading edition
The carbon and hydrogen abounding in oily substances fully account for their effects; and their durability is explained from the gradual manner in which they change by the action of air and water.
Bones are much used as a manure in the neighbourhood of London.—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 would probably be repaid by the increase of their fertilizing powers; and in the state of powder they might be 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 manufacture, may be advantageously employed in the same way.
The basis of bone is constituted by earthy salts, principally phosphate of lime, with some carbonate of lime and phosphate of magnesia; the easily decomposed 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
100.
M. Merat Guillot has given the following estimate of the composition of the bones of different animals.
Phosphate of lime.Carbonate of lime.
Bone ofCalf,54
Horse, 67.51.25
Sheep,705
Elk,901
Hog,521
Hare,851
Pullet,721.5
Pike,641
Carp,455
Horses'Teeth,85.5 25
Ivory,"641
Hartshorn, 271
The remaining parts of the 100 must be considered as decomposable animal matter.
Horn is a still more powerful manure than bone, as it contains a larger quantity of decomposable animal matter. From 500 grains of ox-horn, Mr. Hatchett obtained only 1-5 grains of earthy residuum, and not quite half of this was phosphate of lime. The shaving 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.
—[Davy's Ag. Chem.