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.

Provider: This material has been provided by The University of Leeds Library. The original may be consulted at The University of Leeds Library.

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    extracted, the steam is condensed, and the oil either floats to the top or sinks to the bottom of the water. A few, as oil of lemon, are obtained by expression from a fruit. Their composition varies very much. The simplest are mixtures of an elseoptene with a stearoptene which may be separated by careful fractional distillation. Examples of other bodies found in volatile oils are many of the hydrocarbons closely allied to Terpene {e.g. Cymene, C,oHi.i, in oil of thyme). Aldehydes (Cinnamic Aldehyde, in oil of cinnamon), Phenol derivatives (Eugenol, in oil of cloves), Ethereal Salts (Methyl Salicylate, in oil of wintergreen). Examples in B. P.: Olea Anethi, Anisi, Cinnamomi, Lavandulte, Terebinthinfe, &c. Elaeoptenes are liquid hydrocarbons isomeric with terpene (CioHig). Stearoptenes are oxidised hydrocarbons usually solid and crystalhne. They are more soluble in water than elteoptenes. The volatile oils from which Aquae are prepared all contain stearoptenes. Those in B. P. are Camphora, Menthol, Thymol. Resins are very complex bodies. They are among the products of oxidisation of volatile oils. They contain many indifferent substances and acids. They are soluble in alkalies, forming resin soaps. Hence the alkah in Decoctum Aloes Compositum, Tinctura Guaiaci Ammoniata, and Tinctura ValerianaD Ammo- niata. They are insoluble in water, but not in alcohol, therefore they may be prepared by extraction with alcohol and precipitation with water; also this is the_ reason for the precipitate which falls when water is added to a resinous tincture. D 1 '^i^®,,?' ^\ ^'^'^ ^^'^ llesina, Resina Giiaiaci, Jalapro, i-oaophylh, and .Scammoniiu, Pix Biugundica, and Mastiche.