Very efficient preparations may be also constructed by adding together equal weights of lard and narcotic vegetable powders, as those of Conium, Digitalis, Belladonna, &c.
The addition of a small quantity of powdered white sugar will frequently prevent ointments becoming rancid.
UVÆ URSI FOLIA. L.E.D (Arbŭtus Uva Ursi.)
Uva Ursi, Bear-berry, or Trailing Arbutus.
Bear’s Whortle-berry, Wild Cranberry, &c.
Qualities. Odour, slight, resembling that of hyson tea; Taste, bitterish and sub-astringent. Chemical Composition. Tannin, mucilage, gallic acid, extractive, resin, and traces of lime. Solubility. Both water and alcohol extract its virtues. Med. Uses. The ancients employed it on account of its astringency, the moderns however have exhibited it for various diseases, more especially for those affecting the bladder and urinary organs, and, it would seem, without any theory respecting its modus operandi; but it has at length fallen into disrepute, and probably with justice: it occasionally renders the urine of a blackish colour, a fact which is not easy to be explained. When it is administered, the form of powder is preferred, and in doses from ℈j to ʒj. The leaves of the Vaccinium Vitis Idæa (Red Whortle-berry,) are sometimes substituted for those of Uvæ Ursi; but they may be easily distinguished; botanically, by the net work appearance of their veins above, and by their dots underneath; chemically, by their infusion neither precipitating the solution of isinglass, nor that of sulphate of iron.
ZINCI OXYDUM. L.E.D.
Oxide of Zinc.
This is occasionally used internally as a tonic, and may be exhibited in the form of pill. It is however principally employed externally, as a mild but efficient astringent; viz. Ung: Zinci. Adulterations. Dr. Roloff of Magdeburg has lately discovered the casual presence of Arsenic[[719]] in this oxide; by boiling the substance in distilled water, and assaying the solution with the ammoniaco-nitrate of silver, its presence may be instantly recognised; Chalk may be detected by sulphuric acid exciting an effervescence; and White Lead, by its forming an insoluble sulphate of lead. It ought to be volatile.
ZINCI SULPHAS. L.E.D.