C H A L C A N T H A. 607

cavities. It requires a somewhat smart blow to break it, and shews, when broken,a very rugged and spungy surface. It is naturally of a rusty black in colour, but issometimes considerably reddish, and at other times blueifh, and is always slain’d insome places with spots of a rust colour, and others greenish or blueifh, and in the placeswhere it is free from these, it is somewhat bright or sparkling. It is of a very sharpand disagreeable taste, and os a strong and nauseous smell.

It will not give fire with steel.

It ferments not at all in Aqua Fortis.

It burns to a deep purple.

Water dissolves a part of it, which, when separated by crystallization, appears tobe pure blue Vitriol, shooting into very regular Rhomboidal Crystals, and tinging ironof a copper colour, by wetting and rubbing it on it.

It is found in many parts of the Turkish dominions, particularly in Gallogræcia, andin some parts of Germany; in the last of these places it is boil’d for the Vitriolit contains, and in the former it is mix’d with lime, and made into a paste withwater, which is laid on such parts of the body as they wou’d eradicate the hair from,which purpose it effects in a few minutes.

The Antients us’d it externally to take off pimples, and put a piece of it into a hol-low tooth, as a remedy for the tooth ach. There can be no doubt of theirs being thesame substance with this, since Dioscorides describes it to have been black, full of smallcavities, fattifh or moist on the surface, as ours always is in damp weather, and of adisagreeable taste and smell.

This, the two preceding, and the following substance, are all properly ores of Vi-triol j the particles of those Salts being so perfectly blended in them, as not to appearto the naked eye, yet being always separable from them by water.

4 . Chalcanthum aureum , friabile. Quod Melanteria Antiquorum.

Gold colour d) friable Chalcanthum. The Melanteria of the Antients ,

This is another of the suppos’d lost Fossils of the Antients, but is really produc’dat this time in many different parts of the world, tho’ its resemblance to some otherbodies of the Fossil kingdom, has made it almost universally overlook’d by those whohave treated on these subjects.

It is in its most perfect state a very beautiful substance, of a close, even and regulartexture, moderately heavy, and of an extreamly beautiful yellow, like that of the finestgold j it is in this state found in irregular lumps, never very large, being usually from halfan ounce to two ounces in weight, and when pure and solid of a smooth, even and politesurface, tho’ irregularly fhap’d; and as bright, and of as fine a colour on the outsideas within; this is a state, however, in which it is very rarely found, we usually meetwith it either in form of an efflorescence on various species of vitriolic bodies, or inloose, fhattery and friable masses, of rough surfaces, a spungy texture, and a coarseryellow: In either state, however, it so much resembles a more or less pure nativeSulphur, that it is generally mistook for that body.

It is too soft to give fire with steel.

It makes no effervescence with Acids.

Put into the fire it is found to be not at all inflammable, but calcines first to awhitish, and finally to a strong red colour.

Water dissolves a part of its substance, which may be again procur’d from it, inform of Rhomboidal blueifh green Crystals.

It is found about the mines of some parts of the Hartz Forest in Germany, andis often met with on the sides of hills, in different parts of the East Indies, and inAmerica.

Compound