Qualities. Form, tears or small brittle masses: Odour, very fragrant when burning. It has all the chemical properties of a Resin, and is used only for external purposes: see Pix Arida. Officinal Preparations. Empl: Aromatic: D. Empl: Galban: comp: L. Empl: Opii L. Empl: Thuris. D.
ABSINTHIUM. (Artemisia Absinthium) Common Wormwood.
Qualities. Odour, strong and peculiar. Taste, intensely bitter, slightly pungent, and very unpleasant, as its name[[320]] implies. Chemical Composition. Extractive, a small portion of resin, and a green essential oil; in the first of which its bitterness resides, in the last, a narcotic principle; hence the watery extract is not possessed of the nauseous flavour of the plant but retains its bitterness almost entire; the narcotic principle is therefore dissipated by decoction, but its tonic and anthelmintic properties are not impaired by that process. Medical Uses. The whole plant is powerfully antiseptic; and its bitterness renders it stomachic. Infused in ale it forms the beverage known by the name of Purl. Its powers as a vermifuge has bestowed upon it the name of Wormwood. Dose, ℈j, ℈ij; and of the infusion, (made in the proportion of ℥j of the plant to oj of water,) f℥i-f℥iss. Incompatible Substances. Precipitates are produced in the decoction or infusion by Sulphate of Iron, Acetate of Lead, and some other metallic salts. Tartarized Antimony is not in the least affected by it. Off: Prep: Extract: Absinth: D.
ACACIÆ GUMMI. L. (Acacia vera.) Mimosa. Nilotica. E. D. Gum Arabic.
Qualities. It is dry, semi-transparent, brittle and insipid; by exposure to the air it undergoes no other change than loss of colour. Specific Gravity, 1·515. Solubility. It is soluble in water in every proportion, forming a viscid solution, (mucilage). One part dissolved in water affords a fluid of the consistence of syrup; and in two parts, a medium well calculated for the union of dry powders. Gum is also soluble in pure alkalies and lime water, as well as in vegetable acids, especially vinegar, with which it forms a mucilage that may be used as a cement, like the watery solution, and with the additional advantage of not being susceptible of mouldiness.[[321]] It is insoluble in alcohol, as well as in æther and oils. By strong sulphuric acid the gum is decomposed, and a considerable proportion of carbon deposited.[[322]] For a farther history of its habitudes see Mucilago Acaciæ. Medicinal Uses. It is demulcent and nutritious; although it appears in certain states of the body to pass through the bowels without change. When triturated with gum-resins it assists their mechanical division, as in Form: 30. Officinal Preparations. Mucilago Acaciæ. L. E. D. Emulsio Mimosæ Niloticæ. E. Emulsio Arabica. D. Mist. Corn. ust. L. D. (O) Mist. Cretæ. L. D. (O) Mist. Moschi. L. (O) Confect. Amygdal. L. (O) Pulv. Cret. co. L. (O) Pulv. Tragacanth co. L. (B) Trochisci Carbonat. Calcis E. (O) Troch. Glycyrrh. Glab. E. (O) Troch. Glycyrrh. cum Opio E. (O) Troch. Gummos. E. (O). Adulterations. Gum Senegal is not unfrequently substituted for it, but this may be distinguished by its clammy and tenacious nature; whereas genuine gum arabic is dry and brittle; the fraud is of no consequence in a medical point of view. It is also occasionally mixed with the gum of plum and cherry trees; this fraud however, is to be easily detected, for such gum has peculiar properties by which it may be chemically distinguished; see Mucilago Tragacanth.
ACETICA. L.E.D. Preparations of Vinegar.
These preparations consist of vegetable principles dissolved in vinegar. Officinal Preparations. Acetum Aromaticum. E. Acidum Acetosum camphoratum. E. Medicated vinegars were formerly much extolled; the first London Dispensatory contained no fewer than ten, at present the number is reduced to two, viz. Acetum Colchici. L. Acetum Scillæ. L.E.D. which see.
ACETIS HYDRARGYRI. E. Acetas Hydrargyri. D. Acetate of Mercury.
Qualities. Form, small flaky crystals; Colour, silvery white; Taste, acrid. Chemical Composition. Acetic Acid, and Oxyd of Mercury. Solubility. It is soluble in hot, but very sparingly in cold water, and quite insoluble in Alcohol. Forms of Exhibition. It should be always given in pills,[[323]] it is however seldom used. Dose, gr. j. As an external application, a solution of it, in the proportion of grs. j. to f℥i of rose water, has been commended as a cosmetic.
ACETOSÆ FOLIA. L.E. Rumex Acetosa.