Incompatibilities in prescriptions : for students in pharmacy and medicine and practicing pharmacists and physicians / [Edsel Alexander Ruddiman].

  • Ruddiman, Edsel A. (Edsel Alexander), 1864-1954
Date:
1900
Catalogue details

Licence: In copyright

Credit: Incompatibilities in prescriptions : for students in pharmacy and medicine and practicing pharmacists and physicians / [Edsel Alexander Ruddiman]. Source: Wellcome Collection.

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    alkali citrates, are not generally precipitated by the alkali hydrates, carbonates, phosphates, or by borax. The ci- trates also sometimes prevent precipitation of the metals by oxalates and sulphates. In many instances there are double compounds formed. If heat be applied precipitation may take place. ii. The insoluble citrates are transposed by the dilute mineral acids. 12. When a drug containing tannin is added to a mixture of a ferric salt and an alkali citrate, there is a darkening, but the citrate tends to prevent the formation of the black tannate of iron. 13. Citric acid aids the solution of quinine sulphate in water and the solution is fluorescent. If an alkali citrate is now added to this the fluo- rescence is destroyed and in a few minutes a crystalline pre- cipitate forms. This may be dissolved by the further addi- tion of citric acid or a mineral acid. Quinine citrate is soluble in 806 parts of water (N. D., 1326). 14. The presence of an alkali citrate increases the solubility in water of some acids as gallic, salicylic, and benzoic. 15. The citrates of the alka- lies are soluble in water; those of iron, zinc, and copper are moderately soluble; the other single citrates are nearly insol- uble. Citric acid in excess converts the insoluble citrates into the more soluble acid citrates, and the alkali citrates convert them into the more soluble double citrates. [See Acida.] Aciduin Gallicum.— i. An aqueous solution of gallic acid soon decomposes when exposed to air, giving off carbon dioxide, turning yellow, brown, and black, and depositing a black substance ; this coloration is hastened by alkali hydrates, forming tanno-melanic acid (Allen, III. part I. 68). 2. Gallic acid combines with alkali hydrates. In mixtures of the acid and a solution of potassium or sodium hydrate, when the acid is in excess, the color becomes green; when the alkali is in excess, the color is yellow, changing to red and brown. 3. Gallic acid in excess with ammonia water gives a yellow color, but when the ammonia is in excess the color is red brown. 4. It decomposes alkali carbonates, liberating car- bon dioxide and producing colorations similar to those given