CASTOREUM. L.E.D. Castor. (Castor Fiber. (Rossicus.) Concretum sui generis.)
This substance is secreted by the beaver, in bags near the rectum.[[454]] Qualities. Odour, strong and aromatic. Taste, bitter, sub-acrid, and nauseous. Colour, reddish brown. Chemical Composition. Volatile oil, resin, mucilage, extractive, iron, and small portions of the carbonate of potass, lime and ammonia. It contains also, according to the analysis of Laugier, a small quantity of Benzoic acid. The Canadian variety is also stated by Laugier to contain benzoic acid both free and combined. Solubility. Its active matter is dissolved by alcohol, proof spirit, and partially by water; the tincture made with alcohol is the least nauseous, and the most efficacious; the spirit of ammonia is also an excellent menstruum, and in many cases improves its virtues. Forms of Exhibition. It may be given in substance, as a bolus, or in the form of tincture, but its exhibition in the form of extract or decoction is chemically incorrect. Dose, grs. x to ℈j, and, in clysters, to ʒj. Medicinal Uses. It is antispasmodic, and seems to act more particularly on the uterine system. It certainly proves beneficial as an adjunct to antihysteric combinations; it was highly esteemed by Van Swieten, De Haen, and many other German practitioners. Baglivi states that it counteracts the narcotic powers of opium, but this is not the case. Officinal Preparations. Tinct. Castorei.[[455]] L.E.D. Adulter: It is sometimes counterfeited by a mixture of dried blood, gum ammoniacum, and a little real castor, stuffed into the scrotum of a goat; the fraud is detected by comparing the smell and taste with those of real castor; and by the deficiency of the subaceous follicles, which are always attached to genuine specimens. There are two kinds in the market, the Russian and Canadian, the former however, which is the best, has become extremely scarce; it may be distinguished from the latter, by being larger, rounder, heavier, and less corrugated on the outside.
CATECHU EXTRACTUM, L.E.D.
(Acacia Catechu, Extractum.)
Catechu; olim Terra Japonica.[[456]] Japan Earth.
Qualities. There are two varieties of catechu in the market, the one of a light yellowish, the other of a chocolate colour; they differ only in the latter having a more austere and bitter taste. Chemical Composition. Tannin, a peculiar extractive matter, mucilage, and earthy impurities. Solubility. It is almost totally dissolved both by water and spirit. Incompatible Substances. Its astringency is destroyed by alkaline salts; and precipitates are produced by metallic salts, especially by those of iron; and with gelatine it forms an insoluble compound. Medicinal Uses. It is a most valuable astringent. Forms of Exhibition. In infusion, tincture, or powder. (Form. 51, 52, 58, 151.) In the form of a lozenge, from its gradual solution, it may be very advantageously applied in relaxed states of the uvula and fauces; I have found this remedy successful in cases where the sulphate of zinc was inefficient. From its great astringency it also forms an excellent dentifrice, especially when the gums are spongy; for this purpose I have employed equal parts of powdered catechu, and Peruvian bark, with one-fourth the quantity of the powder of myrrh. Dose, grs. x to ℈i. Officinal Prep. Infus. Catechu, Tinct. Catechu, L.E.D. Electuarium Mimosæ Catechu, E.D.
CENTAURII CACUMINA. L.E.D.
(Chironia Centaurium[[457]] Cacumina.)
The flowering tops of the common Centaury.
Qualities. Odour, none; Taste, intensely bitter. Chemical Composition. Mucilage, resin, and bitter matter. Solubility. Alcohol and water dissolve all its active matter. Medicinal Uses. All its value depends upon its bitterness. It entered into the composition of the once celebrated Portland Powder for the gout, for an account of which see page 32. Dose, of an infusion, made in the proportion of ℥j to oj of boiling water, f℥ij; of the dry powder ʒi.