1273. Bones are much used as a manure in various parts of England, and especially in the midland counties. They are also used in Scotland wherever they can be got, and a knowledge of their great value is spreading rapidly over the Continent. They should not be used till they have been broken and laid in heaps to ferment. 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. Bone-dust and bone shavings, the refuse of the turning manufacture, may also be advantageously employed. The basis of bone is constituted by earthy salts, principally phosphate of lime, with some carbonate of lime and phosphate of magnesia; the animal matter in bones consists of fat, gelatine, and cartilage, which seems of the same nature as coagulated albumen. But by far the most valuable properties of bones depend on their mineral constituents. 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; but, according to other chemists, bones contain only about 38 per cent of animal matters, and the rest of their substance is composed of phosphate of lime, carbonate of lime, fluate of lime, carbonate of soda, and a little muriate of soda. Their principal ingredients, however, are phosphate and carbonate of lime, the former, perhaps, being the most useful of all salts as a manure. Crushed bones are generally considered to be next to night soil the most valuable of all manures. To apply bone manure with effect, it is essential that the soil be dry.