A dispensatory, or commentary on the pharmacopoeias of Great Britain : comprising the natural history, description, chemistry, pharmacy, actions, uses, and doses of the articles of the materia medica / by Robert Christison.

  • Christison, Robert, Sir, 1797-1882.
Date:
1848
Catalogue details

Licence: Public Domain Mark

Credit: A dispensatory, or commentary on the pharmacopoeias of Great Britain : comprising the natural history, description, chemistry, pharmacy, actions, uses, and doses of the articles of the materia medica / by Robert Christison. Source: Wellcome Collection.

Provider: This material has been provided by Royal College of Physicians, London. The original may be consulted at Royal College of Physicians, London.

    972/1062 (page 920)
    TBUF.BIN THIN A. present however they are little applied to any direct therapeutic purpose, and are chiefly useful as furnishing resin and oil of turpen- tine. Common turpentine forms part of the Dublin Emplastrum cimmoniaci cum hydrargyro. Resin (Resina, E. L. D.) is in chemical language a generic term, comprising a great variety of vegetable products of allied proper- ties. But in pharmacy it is specially applied to the substance left by the pine-turpentines after removal of their volatile oil. When they are distilled with water, their oil passes over along with wa- tery vapour ; and if the process be continued till the water is all expelled, or if it be carried on without water at all, a translucent, brownish-yellow, somewhat empyreumatized matter remains, which is called Colophony, Black-rosin, or Fiddler’s-rosin. But if the residuum, instead of being allowed to become dry, be freed of the last portions of oil by supplying water from time to time as its vo- lume is reduced by evaporation, an opaque yellow substance is left, which is called Yellow-rosin. And when this is agitated with boil- ing water, and afterwards kept in a state of fusion at a regulated temperature, so as to expel adhering water without occasioning empyreuma, a pale, wine-yellow, translucent or transparent sub- stance is obtained on cooling, which is the resin of pharmacy. Resin is erroneously stated by the English and Irish Colleges to be prepared from the turpentine of the Scotch fir. It is manufactured, as the Edinburgh Pharmacopoeia indicates, from various kinds; and at the present moment is prepared in Britain (Pereira) chiefly from American and sometimes from Bordeaux turpentine. Resin is translucent or often transparent, yellowish, brittle and pulverizable, rather heavier than water, of a feeble terebinthine odour and taste, fusible at a moderate heat, inflammable, soluble in ether and many volatile oils, insoluble in water, partially soluble in boiling rectified-spirit, and capable of uniting by fusion with wax, fixed oils, fats, and spermaceti. The concentrated acids dissolve it, especially with the aid of heat; sulphuric or nitric acid slowly con- verts it chiefly into artificial tannin ; but nitric acid also produces a peculiar organic acid of interesting chemical properties, called Terebintlnc acid by its discoverer, Bromcis. Solutions of potash and soda dissolve it in a great measure, but not entirely,—forming soluble soaps, and leaving a resinous principle undissolved. Resin is not a simple proximate principle, as was till lately supposed, but consists of several principles. These differ somewhat according to the degree of heat used in preparing it. When made carefully with a low and well-regulated heat, it consists in part of a neutral resinous principle, incapable of making a soap with alkalies, but chiefly of a resinous matter allied Silvic acid, which unites with potash or soda to form soaps. This may be obtained apart by di- gesting powdered resin witli cold spirit of the density 870, and then dissolving the residuum in two parts of boiling spirit of the same