The organic constituents of plants and vegetable substances and their chemical analysis / by G.C. Wittstein ; authorised translation from the German original, enlarged with numerous additions, by Baron Ferd. von Mueller.
- Date:
- 1878
Licence: Public Domain Mark
Credit: The organic constituents of plants and vegetable substances and their chemical analysis / by G.C. Wittstein ; authorised translation from the German original, enlarged with numerous additions, by Baron Ferd. von Mueller. Source: Wellcome Collection.
Provider: This material has been provided by the Royal College of Physicians of Edinburgh. The original may be consulted at the Royal College of Physicians of Edinburgh.
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![[Abieten. Liquid hydrocarbon, obtained by distillation from the resin of Pinus Sabiniana. It is a colourless oil of a penetrating orange-like odour, of 0694 sp. gr. at 15°, boiling at 101°. Dis- solves very little in water, in five parts alcohol of 95%. It forms no compound with hydrochloric acid gas, and is slowly decomposed by warm nitric acid. It absorbs a great quantity of chlorine, and becomes thick. The A. is an excellent solvent for fats and volatile oils, except castor oil, though the latter dissolves two-thirds of its own volume of Abieten. Canada balsam dis- solves two parts Abieten, Peru balsam one-fifth its volume. Wenzel.] Abietic Acid. The constitution of colophony, i.e., of the resinous substance exudated from coniferous trees by incisions of the stem, and which is fused afterwards in order to volatilise the essential oils, is, according to Maly, materially different, and especially much less complicated than it was heretofore considered. It is not a mixture of several isomeric acids (sylvic, pinic, pimaric acids = C40 H30 O4 ), besides indifferent resins, but consists in the main (more than 90%) of a peculiar acid in the anhydrous form, named by the author Abietic acid, and composed according to the formula Css Hg2 Os . It is a bibasic acid, and crystallises slowly from a solution of colophony in common alcohol (of about 70%), as hydrate = Css H^ Os + 2 HO in crusty masses. The anhydrous acid fuses at 100°, the hydrate not under 165°, 'without losing water; and even in higher temperatures it does not lose more water, until, through long-continued heating, it assumes a yellow or brown colour and becomes decomposed. The so-called sylvic acid was imperfectly purified abietic acid, the pinic acid nothing but genuine colophony, and pimaric acid appears to be nothing else but abietic acid. Absilltllin = C40 H28 Os . The bitter ingredient of Artemisia Absinthium. Precipitate the decoction with tannic acid, mix the washed precipitate with oxyd of lead, dry, treat with alcohol, digest the solution with animal charcoal and evaporate. The remaining Absinthin has the appearance of slightly yellow drops of oil, but solidifies to a hard, indistinctly crystallised mass. It is friable to a powder, not influenced by the atmosphere, neutral, not aromatic, of a very bitter taste, fuses at 120° to 125°; dis- solves very little in cold and sparingly in hot water, readily in alcohol, ether and alkalies; yields no sugar with diluted acids, and dissolves in concentrated sulphuric acid with a brown colour, which changes slowly to a green-blue and becomes dark-blue by a few drops of water, but separates grey flakes by an excess of the latter. Acetic Acid = C4 H3 03 + HO. Discovered in the juice of many plants, and especially of trees. Its properties are well](https://iiif.wellcomecollection.org/image/b21957927_0026.jp2/full/800%2C/0/default.jpg)
