The oleo-resin is perfectly soluble in rectified spirit. It dissolves one-fourth of its weight of carbonate of magnesia by the aid of heat, and remains transparent.

[Pilule Copaibas. Pills of Copaiba. U. S. Two troy ounces of copaiba are mixed with sixty grains of magnesia; when the mass has concreted, it is divided into two hundred pills.]

Therapeutics. Copaiva acts as a stimulant like other tere-binthinate drugs; its influence is more particularly directed to the mucous membranes, especially that of the genito-urinary organs; when taken into the stomach it becomes absorbed, and can be detected both in the breath and urine by the peculiarity of its odour; from the latter fluid it may be separated by ether. It is used with much success in affections of the urethra and bladder, as gonorrhea and gleet, but may also be given advantageously in chronic bronchitis, accompanied by excessive secretion of mucus, and in diseased conditions of the mucous membrane of the rectum; it should be avoided in febrile states of the system, as it acts also as a general stimulant. In large doses it occasionally gives rise to a papular eruption on the skin. The action of the volatile oil resembles that of the balsam itself.

Dose. Of copaiba, 15 min. to 1/2 fl. drm. or more; of oleum copaibas, 10 min. to 1/2 fl. drm. Copaiva may be taken rubbed up with the yolk of egg, or floating upon water or some other liquid, or made into pills with burnt magnesia; or, lastly, dissolved in water by the aid of liquor potassae, with which it forms a soap. Sometimes to hide its disagreeable taste it is put into membranous or gelatinous capsules.

Adulteration. Turpentine and fixed oils may be mixed with copaiva: if a little of the suspected drug is heated on paper, turpentine can be detected by the odour, and all fixed oils by a greasy ring surrounding the resinous stain which pure copaiva leaves. Its power of dissolving carbonate of magnesia may be also used as a test.

Mimosae.

Acacia. Gum Arabica. Acacia gum, exuding from the bark of one or more undetermined species of Acacia, and hardened in the air; collected chiefly in Condofan in Eastern Africa, and imported from Alexandria.

Description. Gum is usually a natural exudation from the tree, sometimes incisions are made to favour its flow; it occurs in small rounded tears of different sizes, almost white and opaque from innumerable fissures on the surface; brittle, devoid of odour, and with a mucilaginous taste. Varieties of gum, as Senegal and Barbary gum, in larger tears, more coloured, and less pure, are found in commerce; the produce of different Acacias, as A. Senegal and A. gummifera.

Prop. & Comp. Gum is entirely soluble in water if pure, forming a mucilage; it contains usually about 17 per cent. of water, and leaves on incineration 3 per cent. of ash: the solution forms an opaque white jelly with subacetate of lead. The principal ingredient of gum, is arabine, (C12 H11 O11) Arabine is converted by the action of nitric acid into mucic acid, but is not convertible into sugar. The powder does not become blue on the addition of iodine.

Off. Prep. Mucilago Acaciae. Mucilage of Gum Arabic. (Gum arabic, in small pieces, four ounces; distilled water, six fluid ounces.)

Gum is contained also in pulv. tragacanth. c. and other officinal preparations.

Therapeutics. Gum acts simply as a demulcent, and is sometimes employed to allay irritation of the mucous membranes, as of the fauces, pharynx, and stomach; it is, however, more frequently used for the purpose of suspending heavy powders, as nitrate of bismuth, oxide of zinc, etc, when administered in the liquid form; also to unite substances into the form of lozenges. Gum has been used also in diabetes mellitus, as a substitute for amylaceous matters, as it is not converted into sugar, but its use does not appear to be attended with any real benefit; whether it passes into the urine unchanged is not known; it is, however, often used in irritation of the bladder and urethra.

Dose. Gum may be given ad libitum; the author has given 1/2 lb. per diem in diabetes, without any perceptible symptom being produced.

Catechu Nigrum. Black Catechu. An extract from the wood of Acacia Catechu; Lin. Syst., Polygamia moncecia; imported from Pegu.

Catechu Pallidum. Pale Catechu. An extract from the leaf of Uncaria gambir; Lin. Syst., Pentandria monogynia, belonging to the natural order Cinchonaceae; prepared at Singapore, and in the islands of the Eastern Archipelago. [Catechu. Catechu. An extract prepared principally from the wood of Acacia Catechu. U. S.]

Description. The dark catechu, produced by the acacia catechu occurs in irregular-shaped masses, consisting of layers enveloped in rough leaves, hard, yet brittle; of a blackish-red colour and shining surface, with a very astringent and bitter taste, followed by an impression of sweetness. The pale catechu occurs in cubical pieces about an inch in diameter, which are porous in texture; externally of a reddish-brown colour, internally ochrey yellow or pale brick red; of a dull earthy fracture; bitter and astringent taste: it is the produce of Uncaria gambir. The pieces are now less irregular in shape. There are many other trees which yield catechu, as the Areca catechu, or Betel-nut, etc. In fact the extracts of the different parts of many plants possess properties not unlike the substances under consideration.

Prop. & Comp. Dark catechu is heavier than pale. The former has sp. gr. 1.45; the latter 1.39. The different varieties of catechu consist mainly of mimotannic acid and catechin. Mimo-tannic acid is soluble in cold water, and is distinguished from gal-lotannic acid by its yielding a greenish precipitate with persalts of iron; by not precipitating tartarized antimony; and by not yielding pyrogallic acid when heated; when exposed in a moist state it becomes dark red from the absorption of oxygen, and is rendered insoluble. Catechin is insoluble in cold water, but soluble in boiling water, alcohol, and ether; the solutions do not precipitate gelatine, and strike green with persalts of iron; it is converted by the action of alkalies and their carbonates into Japonic and Rubinic acids. It crystallizes in colourless needles its composition is represented by the formula, HO, C20 H9 O8. Besides these substances, an extractive matter, mucilage, and insoluble compounds, are contained in catechu. Sir H. Davy found the following per-centage of principles in pale and dark catechu. Under the head of tannin, catechin and mimotannic acid are included.

The pale variety is entirely soluble in boiling water. The decoction when cool is not rendered blue by iodine.

Off. Prep. Infusum Catechu. Infusion of Catechu. [Infu-sum Catechu Compositum. U. S.] (Powdered catechu, one hundred and sixty grains; cinnamon, bruised, thirty grains; boiling distilled water, ten fluid ounces). [Powdered catechu, half a troy ounce; powdered cinnamon, sixty grains; boiling water, a pint. U. S.]

Pulvis Catechu Compositus. Compound Powder of Catechu. [Not officinal in U. S. P.] (Catechu, four ounces; kino, rhatany, each two ounces; cinnamon and nutmeg, each one ounce.)

Tinctura Catechu. Tincture of Catechu. (Powdered catechu, two ounces and a half; cinnamon, bruised, one ounce; proof spirit, one pint. By maceration and percolation.)

Trochisci Catechu. Catechu Lozenges. [Not officinal in U. S. P.] (Pale catechu, in powder, two ounces; refined sugar, in powder, one pound; gum arabic, in powder, one ounce; tincture of capsicum, half a fluid ounce; distilled water, a sufficiency. Divide into 720 lozenges.)

Therapeutics. Catechu acts as a very powerful astringent, from the mimotannic acid and catechin contained in it. The catechin is astringent, but as it is very insoluble, its action is probably more local than that of the mimotannic acid, which probably is identical with that of ordinary tannic acid. (See Tannic and Gallic Acid.) Catechu is used chiefly in affections of the alimentary canal, as in diarrhoea, and in some forms of atonic dyspepsia, accompanied with pyrosis; it may also be employed as a remote astringent in haemorrhages and mucous discharges. Externally it may be used in the form of ointment, but has no advantage over the ointment of gall-nuts. It may be chewed, and the juice gradually swallowed in relaxed conditions of the uvula, palate, etc., and in some forms of hoarseness.

Dose. Of the powder, 10 gr. to 30 gr. or more; of infusum catechu, 1 fl. oz. to 1 1/2 fl. oz.; of tinct. catechu, 1 fl. drm. to 2 fl. drm.; of trochisci catechu, from one to three or more; of pulvis catechu, 15 gr. to 60 gr.

Indigo. Prepared from several species of Indigofera; Nat. Order, Leguminosae; is introduced into Appendix B. of the Pharma-copceia for making the following preparation: