Spermaceti. E.D.
Qualities. Form, flakes, which are unctuous, friable, and white. Odour and taste, scarcely perceptible. Sp. Grav. 9·433. It melts at 112°. Chemical Composition. It is a peculiar modification of fatty matter. Solubility. It is insoluble in water and cold alcohol, but soluble in hot alcohol, ether, and oil of turpentine, but it concretes again as the fluids cool; in the fixed oils it is completely soluble. The alkaline carbonates do not affect it, but it is partially dissolved in the pure alkalies, and with hot ammonia it forms an emulsion which is not decomposed on cooling. Uses. It is demulcent and emollient, but it possesses no advantages over the bland oils. Forms of Exhibition. It may be suspended in water by means of mucilage or yolk of egg. (Formulæ 76, 78, 79.) Officinal Preparations. Ceratum Simplex. E. Ceratum Cetacei. L. Unguent. Cetacei. L.D. From exposure to hot air, it becomes rancid; but it may be again purified, by being washed in a warm solution of potass.
CINCHONA. L.E.D. Bark. Peruvian Bark.
Jesuit’s Bark.
Notwithstanding the labours of the Spanish botanists, the history of this important genus is still involved in considerable perplexity, and owing to the mixture of the barks of several species,[[459]] and their importation into Europe under one common name, it is extremely difficult to reconcile the contradictory opinions which exist upon the subject, nor indeed would such an investigation be consistent with the plan and objects of this work. Under the trivial name officinalis, Linnæus confounded no less than four distinct species of cinchona, and under the same denomination the British Pharmacopœias, for a long period, placed as varieties the three barks known in the shops; this error indeed is still maintained in the Dublin Pharmacopœias, but the London and Edinburgh colleges have at length adopted the arrangement of Mutis, a celebrated botanist, who has resided in South America, and held the official situation of Director of the exportation of bark for nearly forty years.
Cinchonæ Cordifoliæ Cortex. L.E. Cortex Peruvianus. D. Heart-leaved Cinchona Bark, commonly called Yellow Bark.
Cinchonæ Lancifoliæ Cortex. L.E. Cortex Peruvianus. D. Lance-leaved Cinchona Bark, common Quilled bark—Pale bark.
Cinchonæ Oblongifoliæ Cortex. L.E. Cortex Peruvianus. D. Oblong-leaved Cinchona Bark, called Red bark.
Qualities. The odour and taste of these three species are essentially the same, although they differ in intensity. They are all bitter, sub-astringent and aromatic, but the flavour of the Yellow bark is incomparably the most bitter, although less austere and astringent, whilst the red bark has a taste much less bitter, but more austere and nauseous than either of the other species. Chemical Composition. Few vegetable substances have been more frequently, or more ably submitted to chemical analysis than the Peruvian bark, and yet but few results of any great practical utility had been obtained previous to the recent experiments of Pelletier and Caventou, communicated to the Academy of Sciences at Paris, since the publication of the fourth edition of the present work.
Dr. Maton[[460]] had several years ago observed, that an infusion of nutgalls produced a precipitate with the decoctions of Bark; a fact which necessarily produced considerable speculation. Seguin was induced to regard it as arising from the presence of gelatine, (see p. 56,) an opinion which Dr. Duncan proved to be erroneous, and shewed that it depended upon a new proximate principle, to which M. Gomez of Lisbon had previously assigned the name of Cinchonine. Besides which, bark was considered as containing resin, extractive, gluten, tannin, a small portion of volatile oil, and some salts with a base of lime; one of which however had been only found in Yellow bark, and had been discovered to contain a peculiar vegetable acid, denominated by Vauquelin Kinic, a name which Dr. Duncan very judiciously superseded by that of Cinchonic acid.