The most essential difference in the composition of these bones is that those of man contain three times as much carbonate of lime as those of the ox; and that the latter are richer in phosphate of lime and magnesia in the same proportion. Fernandez de Barros has established a comparison between the phosphate and carbonate of lime in the bones of different animals. He found in 100 parts of earthy salt of the bones of the following animals:—
| Phosphate of lime. | Carb. lime. | |
|---|---|---|
| Lion | 95·0 | 2·5 |
| Sheep | 80·0 | 19·3 |
| Hen | 88·9 | 10·4 |
| Frog | 95·2 | 2·4 |
| Fish | 91·9 | 5·3 |
The bones of fish are divided into those which contain earthy salts and those which have none, called cartilaginous fishes. The enamel of the teeth is composed as follows:—
| Human enamel. | Ox enamel. | |
|---|---|---|
| Phosphate of lime with fluate of lime | 88·5 | 85·0 |
| Carbonate of lime | 8·0 | 7·1 |
| Phosphate of magnesia | 1·5 | 3·0 |
| Soda | 0·0 | 1·4 |
| Brown membranes attached to the tooth, alkali, water | 2·0 | 3·5 |
| 100·0 | 100·0 |
In the arts, the bones are employed by turners, cutlers, manufacturers of animal charcoal; and, when calcined, by assayers for making cupels. In agriculture, they are employed as a manure, for which purpose they should be ground in a mill, and the powder sowed along with the seeds in a drill. It is supposed, in many cases, to increase the crop in weight of grain and straw together, by from 40 to 50 per cent. In France, soup is extensively made by dissolving bones in a steam-heat of two or three days’ continuance. The shavings of hartshorn, which is a species of bone, afford an elegant jelly: the shavings of calves’ bones may be used in their stead.
Living bones acquire a red tinge when the animals receive madder with their food; but they lose it when the madder is discontinued for some time.
BONE BLACK (Noir d’os, Fr.; Knochenschwartz, Germ.), or Animal charcoal, as it is less correctly called, is the black carbonaceous substance into which bones are converted by calcination in close vessels. This kind of charcoal has two principal applications; to deprive various solutions, particularly syrups, of their colouring matters, and to furnish a black pigment. The latter subject will be treated of under [Ivory Black].
The discovery of the antiputrescent and decolouring properties of charcoal in general, is due to Lowitz, of Petersburg; but their modifications have occupied the attention of many chemists since his time. Kels published, in 1798, some essays on the discolouring of indigo, saffron, madder, syrup, &c. by means of charcoal, but he committed a mistake in supposing bone black to have less power than the charcoal of wood. The first useful application of charcoal to the purification of raw colonial sugar was made by M. Guillon, who brought into the French markets considerable quantities of fine syrups, which he discoloured by ground wood charcoal, and sold them to great advantage, as much superior to the cassonades of that time. In 1811, M. Figuier, an apothecary at Montpellier, published a note about animal charcoal, showing that it blanched vinegars and wines with much more energy than vegetable charcoal; and, lastly, in 1812, M. Derosnes proposed to employ animal charcoal in the purification of syrups and sugar refining. The quantities of bone black left in the retorts employed by MM. Payen, for producing crude carbonate of ammonia, furnished abundant materials for making the most satisfactory experiments, and enabled these gentlemen soon to obtain ten per cent. more of refined sugar from the raw article than had been formerly extracted, and to improve, at the same time, the characters of the lumps, bastards, treacle, &c.
