Materia medica and therapeutics : an introduction to the rational treatment of disease / by J. Mitchell Bruce.

  • John Mitchell Bruce
Date:
1886
Catalogue details

Licence: Public Domain Mark

Credit: Materia medica and therapeutics : an introduction to the rational treatment of disease / by J. Mitchell Bruce. Source: Wellcome Collection.

    30/650
    Detected by: Precipitates with (NH4)2S, or Ii2S ; and sjjecial tests. Yolumetric tests. Non-volatility; insolubility in HNOo. Yarious tests. Blue colour with iodine. Evaporation; quantitative test. EfEervescence with acids. In the case of organic drugs, impurities are chiefly to be detected by careful physical examination and special quantitative tests. Composition.—The composition of the inorganic drugs is expressed by their name and formula. On the 'other hand, the organic drugs are frequently highly complex, the chief proximate principles being the fol- lowing : Fixed oils, volatile oils, resins, oleo-resins, gums, gum-resins, balsams, pectin, alkaloids, acids, neutral sub- stances, glucosides, starch, sugar, cellulose, albuminous substances, ferments, colouring matter, salts, and extrac- tives. Some of these demand general consideration here. A complete list of each will be found on page 420. Fixed oils are extracted by expression (if possible, without the aid of heat) from the seeds or fruits of plants, or from animal tissues. They are compounds of fatty acids (oleic H,Ci8H330o, palmitic HjO^gHg^Oo, and stearic HjCigHg^Og, as well as others less common) with the radical glyceryl C3H5. With caustic alkalies or metallic oxides they form soaps ; the metal com- bining with the acids, and displacing the glyceryl, which is hydrated, and becomes glycerine 03115(110)3. 3NaH0 4- C:iHi53Ci8H,;50. = 3NaCi8H3.^02 + C,H,(H0)3. Hydrate of Oleate of Glvceryl Olcate of Sodium Hydrate of Gly- Sodium. (VegetableOil). ,(Hai-d Soup), ccryl (Glyceriue). 2.. Impurities derived from the apparatus used. 3. Insufficient strength. Impurity. Metals, es- pecially lead, ] iron, and copper. } 4. Fraudulent a dultera - tions. Various colour- ed earths. Cheap salts. ■{ Starch. Sugar. Chalk.