their origin, formation, composition, texture, variety, offices, &c. See **Anatomy**, Part I.

**Bones Whitened for Skeletons.** Two processes are described in the *Acta Hoffmannia* for whitening bones. Professor Rau had a method of giving them a great degree of whiteness. By bare exposure to the air, sun, and rain, for a length of time, they become notably white; but the whitest bones, kept in rooms tainted with smoke or fuliginous vapours, grow in a little time yellowish, brownish, and unsightly. It is customary for the purification of bones, to boil them in alkaline liquors; which, by dissolving and extracting the superfluous fat, improve their whiteness.

**Bones Hardened and Softened.** Boerhaave observes, that alkaline salts render bones harder and firmer, and that acids make them softer and more flexible. These effects succeed in certain circumstances, but not universally; for bones may be hardened and softened both by acids and by alcalies, according to the quantity of saline matter employed, and the manner in which it is applied. Neumann made bones harder and more compact by treating them with the strongest of the mineral acids; though, when the acid is in sufficient proportion, it destroys or dissolves them. In Papin's digester (a strong clove vessel, in which the steam of boiling liquids is confined, and the fluid by this means made to undergo a greater degree of heat than it could otherwise sustain), the hardest bones are reduced in a short time, by the action of simple water, into a soft pap, or jelly; and alkaline liquors produce this effect still sooner.

In the history of the French Academy for the years 1742 and 1743, there is an account that Mr Geoffroy produced before the academy a small ivory spoon, which, by long lying in mustard, was become flexible and transparent like horn; that Mr Fouchy saw an ivory spoon, which, by lying for a considerable time in milk, was become supple like leather; and that Mr Hunauld produced bones, which had been softened by steeping in vinegar, afterwards hardened to their natural state by steeping in water, and softened a second time by steeping in vinegar. Dr Lewis observed that the nitrous and marine acids diluted, and the acetic acid, make bones flexible and tough like leather; but that the diluted vitriolic acid, though it renders them notably soft, makes them at the same time brittle. It seems as if a great part of the earthy matter, which is the basis of the bone, and on which its hardness depends, was dissolved and extracted by the three first; whilst the latter, incapable of dissolving this kind of earth into a liquid form, only corrodes it into a kind of selenitic concrete, which remains intermixed in minute particles among the gelatinous matter. Dr Lewis did not find that the softened bones, whatever acid they were softened by, recovered their hardness by steeping in water. Slips of softened ivory, after lying above a month in water, continued nearly as soft as when they were taken out of the acid liquor.

There is a singular induration of bones produced by fire; the effects of which agent are here remarkably different according to its degree and the circumstances of its application. Bones exposed to a moderate fire, either in open vessels, or in contact with the burning fuel, become opaque, white, and friable throughout; and an increase of fire, after they have once suffered this change, renders them only more and more friable. But if they are urged at first with a strong fire, such as that in which copper or iron melts, they become hard, semitransparent, and porous, like the hard mineral stones. This curious experiment deserves to be further prosecuted.

**Colouring of Bones.** Bones may be stained of a variety of colours by the common dyeing infusions and decoctions of animal and vegetable substances. They are stained also, without heat, by metallic solutions; and by means of these may be spotted or variegated at pleasure. Thus, solution of silver in aqua fortis gives a brown or black according to its quantity; solution of gold in aqua regia or in spirit of salt, a fine purple; solution of copper in the acetic acid, a fine green; and solutions of the same metal in volatile alkalies, a blue, which at first is deep and beautiful, but changes, upon exposure to the air, into a green or bluish-green. If the bone is but touched with the two first solutions, and exposed to the air, it does not fail to acquire the colour in a few hours: In the two latter, it requires to be steeped for a day or longer in order to its imbibing the colour. In these and other cases where immersion for some time is necessary, the bone may be variegated, by covering such parts as are to remain white, with wax or any other matter that the liquor will not dissolve or penetrate.

**Economical Uses of Bones.** Bones are a very useful article, not only for making different kinds of toys, but likewise in several of the chemical arts; as, for making cast iron malleable, for absorbing the sulphur of sulphureous ores; for forming teats and cups, or vessels for refining gold and silver with lead, (burnt) bones composing a mass of a porous texture, which absorbs the vitrified lead and other matters, while the unvitreifiable gold and silver remain entire behind; for the preparation of milky glazes and porcelains; for the rectification of volatile salts and empyreumatic oils; and for making glue. The bones of different animals are not equally fit for these uses; even the glue, or gelatinous part of the bones of one animal is notably different both in quantity and cohesiveness from that of another.

The human skull-bone, or cranium, the natural defense of the seat of sensation and perception in the noblest animal, has been recommended medicinally as a cure for epilepsies, deliria, and all disorders of the senses, from the same philosophy which ascribed antiallamic virtues to the lungs of the long-winded fox; and expected, because fowls are said to digest even small stones, that the skin of the gizzard, dried and powdered, would produce a similar effect in the human stomach. To such lengths of extravagance have the sons of physic been carried by the blind superstition of former ages!

Bones in the Funeral Solemnities of the Ancients.—Divers usages and ceremonies relating to the bones of the dead have obtained in different ages; as gathering them from the funeral pile, washing, anointing, and depositing them in urns, and thence into tombs; translating them, which was not to be done without the authority of the pontiffs; not to say worshipping of them, still practised to the bones of the saints in the Romish church. Among the ancients, the bones of travellers and soldiers dying in foreign countries were brought home to be buried; till, by an express S. C., made during the Italic war, it was forbid, and the soldiers' bones ordered to be buried where they died.

The Romans had a peculiar deity under the denomination of Offalago, to whom the care of the induration and knitting of the human bones was committed; and who, on that account, was the object of the adoration of all breeding women.

Fossil, or Petrified Bones, are those found in the earth, frequently at great depths, in all the strata, even in the bodies of stones and rocks; some of them of a huge size, usually supposed to be the bones of giants, but more truly of elephants or hippopotami. It is supposed they were repolished in those strata when all things were in a state of solution; and that they incorporated and petrified with the bodies where they happened to be lodged.

We often find in the earth petrified bones, greatest part of their gelatinous matter being extracted by the moisture, and a flinty one introduced in its room. In some parts of France petrified bones are met with which have an impregnation of copper. Hence, on being calcined in an open fire, a volatile salt is produced from the remains of their gelatinous principle, and the bone is tinged throughout of a fine greenish-blue colour, copper always striking a blue with volatile alkalies. The French turcoise stones are no other than these bones prepared by calcination; they are very durable, and bear to be worked and polished nearly in the same manner as glaas; without the imperfection, inseparable from glassy bodies, of being brittle. See the article Turcoise.

There have lately been discovered several enormous skeletons, five or six feet beneath the surface, on the banks of the Ohio, not far from the river Miami in America, 700 miles from the sea-coast. Some of the tusks are near seven feet long; one foot nine inches at the base, and one foot near the point; the cavity at the root or base, 19 inches deep. Besides their size, there are several other differences which will not allow the supposition of their having been elephants: the tusks of the true elephant have sometimes a very slight lateral bend; these have a larger twist, or spiral curve, towards the smaller end: but the great and specific difference consists in the shape of the grinding teeth; which, in these newly found, are fashioned like the teeth of a carnivorous animal; not flat and ribbed transversely on their surface like those of the modern elephant, but furnished with a double row of high and conic processes, as if intended to masticate, not to grind, their food. A third difference is in the thigh-bone, which is of great disproportional thickness to that of the elephant; and has also some other anatomical variations. These fossil bones have been also found in Peru and the Brazils; and when cut and polished by the workers in ivory, appear in every respect similar. It is the opinion of Dr Hunter, that they must have belonged to a larger animal than the elephant; and differing from it, in being carnivorous. But as yet this formidable creature has evaded our search; and if, indeed, such an animal exists, it is happy for man that it keeps at a distance; since what ravage might not be expected from a creature, endowed with more than the strength of the elephant, and all the capacity of the tiger?

Bone-Sawing. See Farriery, § xxvi.

Bon-Espérance, the same with the Cape of Good Hope. See Good Hope.