Terebinthina Chia. Chian Turpentine. (Not officinal.) An oleo-resin flowing from the incised trunk of the Pistacia ter-ebinthus; Lin. Syst., Dioecia pentandria. The tree from which this oleo-resin is obtained grows chiefly in the island of Chios.

Description. This substance is about the consistence of honey, and is semi-transparent, of a white or pale yellow colour, having a fragrant odour and warm taste.

Prop. & Comp. It consists of resin dissolved in a volatile oil resembling that of turpentine.

Therapeutics. Its action is the same as that of the other turpentines; vide Terebinthina Americana.

Mastiche. Mastich. A resinous exudation flowing from the stem of Pistacia Lentiscus, native of the countries bordering on the Mediterranean; chiefly imported from Turkey and the Levant.

Description. In its best condition it occurs in small masses called tears, which are of light yellow colour, friable, becoming soft and ductile when chewed; the fracture vitreous, shining, and transparent; the surface of the tears is often covered with a whitish dust, produced by the rubbing together of several pieces. The larger masses are less pure than the small; they are formed by the agglutination of several tears, and often mixed with bark and earthy matter. It has a faint agreeable odour.

Prop. & Comp. It is wholly soluble in ether and chloroform but scarcely at all so in the fixed oils; it contains a small quantity of volatile oil; alcohol dissolves about four-fifths of it, and the remainder, which is soluble in ether, has been called Masticine (C40 H31 O2).

Therapeutics. The action is the same as that of the resin of turpentine; it is but little used. From its agreeable odour,, which it communicates to the breath, it is sometimes employed as a masticatory. Dissolved in chloroform or ether, it is often used for stopping carious teeth.

Dose. 20 gr. to 40 gr.

Myrrha. Myrrh. A gum-resin exuding from the bark of Bal-samodendron Myrrha; Lin. Syst., Octandria monogynia. It is obtained from Arabia Felix and Abissinia.

Description. It occurs in irregular fragments, varying in size; of a reddish-brown or reddish-yellow colour; translucent, but the surface often covered with powder; fractured surface irregular and somewhat oily; of a peculiar aromatic odour, and pungent warm acrid bitter taste. The inferior variety is in much larger masses than the pure, darker coloured, less transparent, and containing earthy and other impurities. The latter variety is also known as Indian myrrh, from its being imported into England from that country. The best of Turkey myrrh comes by way of Egypt and the Levant.

Prop. & Comp. It contains a volatile oil, gum, resin, salts, etc. The resin is bitter, soluble in alcohol, but partly only in ether. With water, myrrh forms an emulsion of a milky-white colour, from the suspension of the resin by the gum which is held in solution.

Off. Prep. Pilula Aloes et Myrrhae. Pill of Aloes and Myrrh. (Socotrine aloes, two ounces; myrrh, one ounce; saffron, dried, half an ounce; confection of roses, two ounces and a half.) [In the U. S. P. syrup a sufficient quantity is directed instead of confection of roses, and the mass is divided into four hundred and eighty pills, each pill containing two grains of aloes.]

Tinctura Myrrhae. Tincture of Myrrh. (Myrrh in coarse powder, two ounces and a half; rectified spirit, twenty fluid ounces. Prepared by maceration and percolation.) [According to the U. S. P. two pints of tincture are prepared by percolation with alcohol from three troy ounces of myrrh.]

Myrrh is also contained in Mist. Ferri C.; Pil. Assafoetidae C.; Pil. Rhei C.; and Decoct. Aloes C.

Therapeutics. Myrrh acts as a stimulant in a manner not unlike other resinous substances; it increases the secretion of the mucous membranes, especially of the bronchial tubes, and is supposed to possess antispasmodic and emmenagogue properties, combined with tonic powers.

Myrrh is frequently administered in conjunction with iron and aloetic preparations in amenorrhaea; also in leucorrheal and other mucous discharges connected with debility: sometimes as an expectorant in chronic bronchitis and phthisis. Externally, as a topical stimulant, it is applied to aphthous sore mouths, spongy gums, etc.

Dose. Of myrrh, 10 gr. to 30 gr.; of tinct. myrrhae, 1/2 fl. drm. to 1 fl. drm. Of pil. aloes c. myrrha, 5 gr. to 15 gr. The tincture is more frequently used externally, mixed with water (2 fl. drm. to 4 fl. oz.), to form a gargle.

Adulteration. Gum bdellium and other gum resins are occasionally met with in samples of myrrh, and an inferior kind is often substituted for good myrrh.

Rhus Toxicodendron. The leaves of the Rhus Toxicodendron (the poison sumach); Lin. Syst., Pentandria trigynia: not now officinal in the British, but is contained in the United States' Pharmacopoeia.

Description. The leaves are trifoliate, leaflets entire, or rarely toothed; ovate, deep shining green on the upper surface, hairy on the under.

Prop. & Comp. The leaves contain a peculiar acrid resin, and gummy extractive. It is on the presence of the former substance that the properties of the plant depend.

Prep. For topical application a tincture of the leaves is made.

Therapeutics. It is chiefly used as a topical irritant. The juice of the leaves causes inflammation and vesication of the part to which it is applied. Internally administered, it is supposed to act on the spinal system in a manner similar to strychnia; in large doses it causes inflammation, etc, of the stomach. It has been recommended in palsy, but further investigations as to its efficacy are required.

Dose. Of the powder, 1/2 gr. to 1 gr., gradually increased.

Olibamim. Gum resin from the Boswellia serrata; Lin. Syst., Decandria monogynia. This resin is not officinal.

Description. It occurs in small oblong tears, of a peculiar balsamic odour.

Prop. & Comp. It burns with an aromatic odour, and contains a volatile oil, resin, and gum.

Therapeutics. It is stimulant, like the other gum resins, but is chiefly used for burning as an incense in Roman Catholic countries.

Elemi. Elemi. A concrete resinous exudation from an uncertain plant, probably Canarium Commune. Chiefly imported from Manilla. [Not officinal in U. S. P.]

Description. It occurs in masses of various sizes, usually of a soft consistence, more or less transparent, of a yellowish colour, with a peculiar fennel-like odour, and a bitter aromatic taste.

Prop. & Comp. The odour is due to the presence of volatile oil; the resin is soluble in alcohol.

Off. Prep. Unguentum Elemi. Ointment of Elemi. (Elemi, quarter of an ounce; simple ointment, one ounce.)

Therapeutics. Action as the turpentines generally; chiefly used externally, in the form of ointment, as a topical stimulant.

Dose. Not given internally.