Materia medica, pharmacy, pharmacology and therapeutics / by W. Hale White.

  • Hale-White, William, Sir, 1857-1949.
Date:
1898
Catalogue details

Licence: Public Domain Mark

Credit: Materia medica, pharmacy, pharmacology and therapeutics / by W. Hale White. Source: Wellcome Collection.

    36/680 (page 14)
    In Ex. Cinclionae Liquidum, Ex. Ergotae, and Ex. Ipecacuanhas Liquidum, g.i?., special substances are used to facilitate the extraction of the active principles, and Ex. Euonymi Siccum contains Calcium Phos- phate to keep the extract in the form of a powder. Extracts are of different kinds. (1) Fresh Extracts.—Heat the juice expressed from the bruised plant to 212° F. to coagulate the albumen, filter, evaporate the filtrate at 160° F. The B. P. contains Ex. Colchici and Taraxaci. Green extracts are a variety of fresh extracts that needs special notice. (2) Green Extracts.—Heat the expressed juice to 130° F. to coagulate the green colouring matter, filter it off; heat the filtrate to 200° F. to coagulate the albu- men. Evaporate the filtrate at 140° F. to a syrupy consistency; add the green colouring matter (which pre- vents absorption of moisture and improves the appear- ance), and evaporate the whole. The B. P. contains only two, Ex. Belladonnas Viride and Hyoscyami Viride. (3) Aqueous Extracts.—Treat dry drugs with cold, hot, or boiling water, and evaporate to a proper consistency. Examples : Ex. Opii, &c. (4) Alcoholic Extracts.—Treat dry drugs with alcohol with or without the addition of water, and evaporate to a proper consistency. Examples : Ex. Cannabis Indicae, Jalapse, &c. In some cases the solid extract is made by evaporation of the official liquid extract, e.g, Ex. Nucis Vomicae and Belladonnje Alco- holicum. (5) Ethereal Extracts.—The dry drug is perco- lated with ether (Ex. Filicis Liquidum), or with alcohol and ether which are distilled off (Ex. Strophanthi). (6) Liquid Extracts.—These are aqueous, or alcoholic, or aqueous and alcoholic extracts evapo- rated to form concentrated liquid solutions of syrupy consistence. If aqueous, some alcohol is added to prevent decomposition, and to precipitate any albu- minous matter, which is then removed by filtration. Examples : Ex. Ergotae Liquidum, Hydrastis Liqui- durii, &G. Most liquid extracts are of such a strength that one fluid ounce represents one ounce of the drug employed.