Arnica (ar'nik-ah)

A genus of the Senecionidae. arnicae flores [U. S. Ph.]. The flower heads of A. montana. arnicae radix [U. S. Ph.]; arnicae rhizoma. See a. root. a. root. The rhizome of A. montana. emplastrum arnicae [U. S. Ph.]. A plaster made by mixing 1 part of the extract of a. root with 2 parts of resin plaster over a water bath. extract of a. root. An extract made by extracting the root of A. montana with dilute alcohol, evaporating the liquid to the pilular consistence, and adding 5 per cent, of glycerin [U. S. Ph.]. extractum arnicae radicis fluidum [U. S. Ph.]. Fluid extract of a. root; made by exhausting powdered a. root with dilute alcohol, reserving the first 90 parts (by volume) of the percolate, evaporating the rest to the consistence of a soft extract, mixing this with the reserved portion and adding enough dilute alcohol to bring the whole up to 100 parts by volume, tinctura arnicae flores. A tincture made by macerating a. flowers in dilute alcohol and filtering [U. S. Ph.]. tinctura arnicae radicis. _ Tincture of a. root; made by macerating in dilute alcohol and filtering [U. S. Ph.]. [Origin unknown.]