Cornu Cervi Pharm. Lond. Hartshorn: large branched horns of the hart or male red deer. The horns usually met with in the (hops are thole of the common or fallow deer.

Hartshorn, rasped or shaved, gives out to water, by boiling, a soft gelatinous matter, of scarcely any particular flavour, amounting, when infpiffated, to about one fourth the weight of the horn. The decoction and jelly are some-times directed in diarrhoeas and other disorders, partly as affording a mild nutriment, and partly for obtunding and incraffating acrimonious thin humours. An elegant hartshorn jelly is. prepared, by boiling half a pound of the fhav-ings in three quarts of water till two parts are wafted, and adding to the strained liquor an ounce of Seville orange or of lemon juice, a quarter of a pint of mountain wine, and half a pound of fine sugar; and boiling down the mixture to a due consistence. Compositions of this kind are very grateful to many in acute diseases.

On distilling the horn with a red heat, it gives over a volatile falt and spirit, together with a fetid empyreumatic oil. The same products are obtainable, in greater or less quantity, from all animal substances, though those prepared from hartshorn have been in most general use: fecial alkalinus volatilis.

The horns, so far freed from their gelatinous matter as to be pulverable, either by boiling them in water or by exposing them to its steam, have been used by some in the same intentions as the absorbent earths: by calcination in a strong fire, with the free admission of air, their earthy part may be obtained in a much purer state, in quantity about one half of the weight of the original horn. The calcination may be performed in a potter's furnace; or by stratifying the horns with charcoal in any common furnace or stove, and setting the whole on fire together: the horns, after the burning, retain their sigure, and a considerable degree of hard-nefs, so as to be easily separable from the ashes into which the vegetable coal is reduced. The horns remaining after the distillation of the volatile falt are as proper for this use as fresh ones.

Cornu cervi philosophice praeparatum.

Cornu cervi uftum Ph. Lond.

The pure earth of hartshorn differs from that of coral and the testacea, in not being convertible into quicklime; and agrees with them, ill being dissoluble by the vegetable, nitrous, and marine acids, and in being precipitated from these acids on the addition of the vitriolic. The earth of the horns, and of the bones also, of other animals, appears to be of the same nature with that of hartshorn. How far this species of earth differs from the others in its medicinal effects, is little known. It is custo-mary, in acute diseases accompanied with a looseness, to impregnate the common drink with the calcined hartshorn levigated into an impalpable powder, on a supposition of its acting as a mild restringent: solutions of it in vegetable acids are apparently restringent, as they discover a degree of austerity to the taste; but the pure earth is insipid, so that probably it tends to restrain fluxes only in consequence of its uniting with acid humours in the first passa-ges. Hoffman reports, that this earth, when combined with acids, is more disposed, than the other absorbents, to promote perspiration.