in natural history, though supposed by many to be an earth, is truly a crustaceous kind of spar, debafed by earth, and therefore not transparent.

It is usually found coating over vegetable, or other bodies, in form of incrustations; so that the true osteocolla is a tubular crustaceous spar, of a very foul and coarse texture, and carries with it much more of the appearance of a marl than of a species of spar.

The masses of osteocollo, though regularly of the same figure, are very different in size; some of them being not thicker than a crow-quill, and others of five and six inches diameter; it is always, however, of a tubular figure, and a wrinkled and rough surface.

Osteocollo is frequent in Germany, where it is found buried near the surface of the earth, sometimes in strata of sand, but more frequently among marls: it should be chosen for use, the purest that can be had of a pale brown colour, and of a tolerably close and firm texture.

It has long been famous for bringing on a callus in fractured bones; its name osteocollo signifying the bone-glue, or bone-binder. It is also recommended as a diuretic, and as good in the fluors albus: but, at present, little regard is paid to it; since, if it has any virtues, they must be wholly owing to spar, which may be given to greater advantage in a purer form.