GAMBOGIA-GAMBOGE.

Gamboge is a GUM-RESIN, procured from Garcinia morella (Nat. Ord. Guttiferæ), a tree of Siam and Cochin-China. The juice is said to be collected, as it exudes from the wounded bark of the tree, in cocoa-nut shells, and is afterwards rolled into cylinders, or transferred to earthen jars to dry; it is sometimes also received into the hollow joints of the bamboo. It is imported from Canton and Calcutta, and occurs in cylindrical rolls from one to three inches in diameter, of an orange colour, known as pipe gamboge, or in irregular masses (which are less pure), weighing two or three pounds or more, called cake or lump gamboge. Good gamboge is opaque, brittle, inodorous, nearly insipid, and breaks with a vitreous fracture; its powder is bright-yellow. It is a gum-resin, forming a yellow opaque emulsion with water, and a golden-yellow solution with alcohol.

Effects and Uses.-Gamboge is a powerful hydragogue, and in overdoses has proved fatal. It is employed in obstinate constipation-in dropsies, combined with cream of tartar or jalap-and has been given to destroy tænia. Dose, gr. ij to gr. vj. It is often prescribed with other and milder cathartics, to promote and accelerate their action. Compound cathartic pills (pilulæ catharticæ compositæ), are made by mixing 32 grains of compound extract of colocynth, 24 grains of extract of jalap and calomel each, and 6 grains of gamboge, and with water forming a pilular mass to be divided into 24 pills. Three of the pills, containing 103 grains of the mass, represent 4 grains of compound extract of colocynth, 3 of extract of jalap and calomel each, and grain of gamboge.

ELATERIUM.

Elaterium is a substance deposited by the JUICE of the FRUIT of Momordica Elaterium, Ecbalium agreste, or Squirting Cucumber (Nat. Ord. Cucurbitaceae), an annual vine of the south of

Europe now cultivated in England. The fruit has the shape of a small oval cucumber, and, when fully ripe, separates from the peduncle, and throws out its juice and seeds with considerable force, through an opening in the base. Pure elaterium is obtained by slicing the fruit, and allowing the juice to drain through a sieve. The juice deposits a sediment, which dries in very light, thin, nearly flat, pulverulent, greenish-gray cakes, and is the genuine elaterium. It is almost inodorous, and has a bitter, acrid taste. The commercial elaterium, which is obtained chiefly from England, is made by expression. The drug is to be considered inferior when it is dark-coloured, much curled, and hard. Elaterium yields its virtues to alcohol and not to water. Its active principle is called elaterin, and proves powerfully cathartic in doses of too of a grain.

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Effects and Uses.-Elaterium is a hydragogue cathartic of great violence of operation, and in overdoses has frequently proved fatal. It has also a diuretic action. It is a very efficient remedy in the treatment of dropsies, and is also a useful revulsive in cerebral affections; but, in administering it, considerable caution is required. Dose of the pure drug (termed Clutterbuck's elaterium), gr. §; of the drug of the shops, gr. j to gr. ij; but it is most safely given in divided doses. Of elaterin, the dose is gr. to gr. 1.

OLEUM TIGLII-CROTON OIL.

Croton oil is a FIXED OIL obtained from the SEEDS of Croton Tiglium (Nat. Ord. Euphorbiaceae), a small tree of the East Indies. The Croton seeds resemble the Castor seeds in shape and size, and consist of a blackish shell, sometimes covered with a yellowish-brown epidermis, and enclosing a yellowish oily kernel. They are highly irritant and cathartic, but are not imported into this country. They contain a volatile oil, a FIXED OIL, resin, crotonic acid, &c. The CROTON OIL of the shops is obtained by expression, and is a mixture of the fixed oil proper, the resin, and crotonic acid. It is made both in India and England, the Indian oil being of a pale straw-colour,

and the English reddish-brown; the latter is the variety now found in the shops. It has a viscid consistence, which is increased by age, a faint peculiar odour, and an extremely acrid, pungent taste; it is soluble in ether and the volatile and fixed oils, and partially so in alcohol.

Physiological Effects.-Croton oil, taken internally, is a powerful hydragogue purgative, occasionally increasing also the secretion from the kidneys. One or two drops are usually sufficient to produce active catharsis, but sometimes as much as eight or ten drops may be taken without affecting the bowels. It operates very speedily, often causing evacuations in half an hour, and is apt to produce considerable depression of the vascular system. In overdoses it has frequently proved fatal. Rubbed on the skin, croton oil causes rubefaction and a pustular or vesicular eruption; and, rubbed over the abdomen, it will sometimes purge.

Medicinal Uses.-Croton oil, from the smallness of the dose required, and the speediness of its action, is an extremely valuable purgative in obstinate constipation, and in cerebral disorders, particularly coma. As a counter-irritant, it is extensively employed in pulmonary and laryngeal affections, diseases of the joints, &c. Dose, one or two drops made into pill, with bread-crumb. For external use, it may be diluted with one or two parts of olive oil or oil of turpentine.

MERCURIAL CATHARTICS.

The preparations of mercury, employed as cathartics, are calomel, blue pill, and mercury with chalk. Their purgative effects depend partly on the increased flow of bile which they occasion, and partly on the stimulus which they give to secretion from the mucous follicles of the intestinal canal, and from the pancreas. They are rarely employed alone, owing to the slowness and uncertainty of their action; but are usually combined with, or followed by other cathartics (as jalap, senna, rhubarb, compound extract of colocynth, or some of the saline preparations). The mercurial cathartics are usually adminis

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2. Refrigerant Diaphoretia.—The saline and ethereal preparations classed as refrigerant see p. 21, produce a gentle relaxing diaphoretic action, unattended with nausea. They are used to allay fibrille excitement.

3. Stimulating Dinkoreti ́s.—This group includes the diffusible stimulants, aromatic substances generally, of every class, and many narcotics, particularly opium and camphor. They are contraindicated in high inflammation, but are very serviceable in rheumatic and pulmonary affections, after vascular excitement has been reduced, and in all diseases where the surface of the body is cold. Opium, in the form of Dover's Powder, may be employed in inflammatory cases, where other stimulating diaphoretics are inadmissible, and is given with advantage in an early stage of acute rheumatism, dysentery, and catarrh, unless the action of the pulse be very strong, when depletion should be previously resorted to. The operation of the diaphoretic stimulants is promoted by the free use of warm diluent drinks, and warm covering to the body.

4. Alterative Diaphoretics.-Under this head are comprised a class of diaphoretic medicines, which produce a gradual and nearly insensible increase of the cutaneous secretion, and are supposed to promote the elimination of noxious matters from the blood, through the vessels of the skin. They are employed chiefly in chronic rheumatic and cutaneous affections, and in secondary syphilis.

ALTERATIVE DIAPHORETICS.

SARSAPARILLA.

The name Sarsaparilla is applied to the ROOTS of Smilax and other species of Smilax (Nat. Ord. Smilaceae), kly shrubs of Mexico, Guatemala, and the warm -f South America. The roots consist of numerous ler pieces, of the average thickness of a writing Seet long, springing from a common head or frequently found in the shops with portions

of the stems attached. Several varieties are known: 1. Honduras Sarsaparilla, the most common variety in the United States, comes in bundles two or three feet long, composed of several roots folded lengthwise, of a dirty grayish or reddishbrown colour. 2. Jamaica Sarsaparilla, which is probably derived also from Central America, comes in shorter bundles, and is known by the red colour of the epidermis. 3. Vera Cruz Sarsaparilla comes in large, loose bales, bound with cords or leather thongs, containing the roots folded on themselves, consisting of a head with numerous long radicals. 4. Brazilian or Rio Negro Sarsaparilla is distinguished by the amylaceous character of its interior structure. 5. Guatemala Sarsaparilla resembles the Brazilian.

Sarsaparilla roots are several feet in length, about the thickness of a goose-quill, cylindrical, more or less wrinkled logitudinally, and consist of a whitish-brown or pink cortical

rtion, covered with a thin gray, brown, or red epidermis, and nclosing a layer of whitish ligneous fibre, and a central pith. The cortical portion is more active than the interior portions; the central medulla contains a good deal of starch. Sarsaparilla, in the dried state, is nearly inodorous, but its decoction has a strong smell. It has a mucilaginous, slightly bitter taste, and, when chewed for some time, produces a persistent acrid impression on the mouth; this acridity of taste is the criterion. of good sarsaparilla. Water and diluted alcohol extract its virtues, but they are impaired by long boiling. It contains an active principle, called smilacin or sarsaparillin, starch, resin, extractive, &c.

Effects and Uses.-The physiological effects of sarsaparilla, beyond a slight diaphoretic action, are not very obvious; in large doses, it occasionally produces nausea and vomiting. Its efficacy, however, in eradicating various morbid symptoms is well established, and its mode of action, though obscure, is generally attributed to a purifying influence on the blood, through the function of the skin. It is employed in secondary syphilis, particularly where the disease resists or is aggravated