Myrrha. - Myrrh. - A gum-resinous exudation from the stem of Balsamodendron myrrha. Collected in Arabia Felix and Abyssinia.

Characters. - In irregular-shaped tears or masses varying much in size, somewhat translucent, of a reddish-yellow or reddish-brown colour; fractured surface irregular and some-what oily; odour agreeable and aromatic; taste acrid and bitter.

Composition. - Myrrh contains about 2 per cent of an oxygenated (ethereal oil, C10H11O, myrrhol; a resin, myrrhin, 35 per cent; and gum 60 per cent. Myrrh forms a milky-white emulsion with water, the resin being suspended by the gum in solution Impurities. - Every variety of resins and gum-resins: detected by appearance, smell, and taste.

Preparations.

1. Pilula Aloes Et Myrrhae

Pilula Aloes Et Myrrhae. 1 in 6. (See Aloe Socotrina, page 357.)

2. Tinctura Myrrhae

Tinctura Myrrhae. 1 in 8. Dose, 1/2 to 1 fl.dr.

Myrrh is also contained in Decoctum Aloes Compositum, Mistura Ferri Composita, Pilula Assafoetida Composita, and Pilula Rhei Composita.

Action And Uses. [1. Immediate Local Action And Uses.

Externally. - Myrrh, is a stimulant and disinfectant like other oleo-resins, and is sometimes used as a dressing for ulcers.

Internally. - It exerts a similar effect upon the mouth, throat, stomach, and bowels. It is much employed as a wash in spongy gums and ulcerated mouth; as a gargle in relaxed throat; and as a stomachic and adjuvant of purgatives m dyspepsia, anaemia, and constipation.

2. Action On The Blood And Its Uses

Myrrh appears to increase the number of leucocytes in the blood; and this fact may in part account for its value along with iron in anaemia.

3. Specific Action

Nothing definite is known on this subject.

4. Remote Local Action And Uses

Like the oleo-resins (see Terebinthinae Oleum) myrrh appears to be excreted by the mucous membranes, especially of the genito-urinary and respiratory tracts, and stimulates them during its passage. It is thus an uterine stimulant and em-menagogue, and is extensively given along with aloes or iron in the amenorrhoea of girls. As a stimulant and disinfectant expectorant it is much less used now than formerly in chronic bronchitis.

Elemi - Elemi. - A concrete resinous exudation, the botanical source of which is undetermined, but is probably Canarium commune. Chiefly imported from Manilla.

Characters. - A soft unctuous adhesive mass, becoming harder and more resinous by age; of a yellowish-white colour; with a rather fragrant fennel-like odour; almost entirely soluble in rectified spirit.

Substances resembling Elemi: Assafoetida, Galbanum, Ammo-niacum, known by smell.

Composition. - Elemi is a mixture of a turpentine and several resinous bodies.

Preparation.

Unguentum Elemi - 1 in 5.

Action And Uses

Elemi acts much like resin of turpentine, and is employed in the ointment as a stimulant and disinfectant to sores and issues.

Leguminosae. Tragacantha - Tragacanth. - A gummy exu-dation from the stems of Astragalus verus. and possibly other species. Collected in Asia Minor.

Characters. - White or yellowish, in broad shell-like slightly curved plates, tough and elastic, but rendered more pulverisable by a heat of l20o Fahr. Very sparingly soluble in cold water; but swelling into a gelatinous mass, which is tinged violet by tincture of iodine. After maceration in cold water, the fluid portion is not precipitated by rectified spirit.

Impurities. - Other gums, and white lead.

Composition. - Tragacanth consists of two gums: bassorin, 33 per cent., comparatively insoluble in water, C12H10O10, and unfermentable; and a gum nearly identical with the arabin of acacia (but precipitated by acetate of lead), 53 percent., soluble in water. It also contains a little starch.

Preparations.

1. Mucilago Tragacanthae

Mucilago Tragacanthae. 1 in 80. Dose, 1 fl.oz. or more.

2. Pulvis Tragacanthse Composifus

Pulvis Tragacanthse Composifus. Tragacanth, 1; Gum Acacia, 1; Starch, 1; Sugar, 3. Dose, 10 to 60 gr. Tragacanth is also contained in Pulvis Opii Compositus.

Action And Uses. 1. Immediate Local Action And Uses

Internally, tragacanth is demulcent. The mucilage may be used as a vehicle for active substances in linctuses for pharyngeal cough. Tragacanth is partly converted into sugar by the stomach; in large quantities it causes indigestion. It is chiefly employed to suspend resins and heavy powders, such as bismuth, the simple gum being preferable to the compound powder, because not fermentable.

2. Action On The Blood, Specific And Remote Local Action

Tragacanth, like other gums, enters the blood and tissues, partly unchanged, partly as sugar and other products, and has a nutritive effect of comparatively low value. It is not used for this purpose. A remote demulcent effect on the urinary organs is probably imaginary only.

Glycyrrhizae Radix - Liquorice Root. - The root or underground stem, fresh and dried, of Gly-cyrrhiza glabra. Cultivated in England.

Characters. - In long cylindrical branched pieces, an inch or less in diameter, tough and pliable; of a greyish-brown colour externally, yellow internally; without odour, of a sweet mucilaginous and slightly acrid taste. Digested with water, it yields a solution which gives a precipitate with diluted sulphuric acid.

Substances resembling Liquorice Root: Pyrethrum and Taraxacum, which are not sweet.

Composition. - Liquorice root contains grape-sugar, gly-cyrrhizin, starch, resin, asparagin, and malic acid. Glycyrrhizin is a yellow amorphous glucoside, C24H36O9, with a strong bittersweet taste and acid reaction, yielding glucose and a very bitter substance, glycyrretin.

Preparations.

1. Extractum Glycyrrhizae

Extractum Glycyrrhizae. Aqueous. Dose, 1/2 to 1 dr.

2. Extractum Glycyrrhizae Liquidum

Extractum Glycyrrhizae Liquidum. Made as above with spirit. 2 fl. oz. = 1 oz. of solid extract. Dose, 1 fl. dr.

3. Pulvis Glycyrrhizae Compositus

Pulvis Glycyrrhizae Compositus. 1, with 1 of Senna and 3 of Sugar. Dose, 30 to 60 gr.

Non-officinal Preparation.

Pulvis Liquiritiae Compositus (Ph. Germ. and Puss.). - 1, with 1 of Senna, 1/2 of Sulphur, 1/2 of Fennel, and 3 of Sugar. Dose, a tea spoonful.

Liquorice or its preparations are contained in many preparations throughout the Pharmacopoeia. It especially covers the taste of senna, chloride of ammonium, senega, hyoscyamus, turpentine, and bitter sulphates. The powdered root is a useful basis for pills.

Action And Uses

Liquorice is chiefly used for the pharmaceutical purposes just indicated. It has a pleasant taste and flavour, and in-creases the flow of saliva and mucus when slowly chewed or sucked, the increased secretions acting as emollients to the throat. Liquorice is therefore a popular demulcent, much used to relieve sore throat and coughs.

Scoparii Cacumina - Broom Tops. - The fresh and dried tops of Sarothamnus Scoparius. From indigenous plants.

Characters. - Straight angular dark-green smooth tough twigs, of a hitter nauseous taste, and of a peculiar odour when bruised.

Composition. - Scoparium contains two active principles, scoparin and spartein, besides other constituents. Scoparin C21H12O10, is a yellow crystalline neutral body, said by some to be a diuretic, by others not so. Spartein, C15H16N2, is a volatile oily-looking liquid alkaloid, allied in appearance, composition, and physiological action to conia. See Conii Fructus, page 250.

Preparations.

1. Decoctum Scoparii

Decoctum Scoparii. 1 dried in 20. Dose, 2 to 4 fl.oz.

2. Succus Scoparii

Succus Scoparii. 3 of juice of fresh tops to 1 of spirit.

Dose, 1 to 2 fl.dr.

Action And Uses

Broom has a bitter stomachic and somewhat astringent action in moderate doses, but is not used on this account. Its further effect on the system is still obscure, the only fact definetly known being that it frequently produces free diuresis.

It is believed that the active principles of the plant, either or both, pass through the blood and tissues, and stimulate the secreting substance of the kidneys during the process of excretion. Broom is therefore extensively used in this country is a diuretic in dropsy, especially cardiac dropsy, but is almost invariably combined with other drugs of the same class, such as digitalis, acetate of potash, etc. It should be avoided in acute renal dropsy.