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.

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. elaterin, the dose is gr. to gr. 1's.

Of

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

tered with a view of combining a purgative action with an effect on the secretions, particularly that of the liver; also, as anthelmintics; and as revulsives in cerebral and other affections. They are well adapted to infantile cases, from the facility of their administration, and are especially beneficial in the ephemeral febrile attacks to which children are subject; they, moreover, rarely produce salivation in children.

HYDRARGYRI CHLORIDUM MITE (Mild Chloride of Mercury, or Calomel). (Noticed at length under the head of Alteratives.) Dose, as a cathartic, gr. vj to xij, in pill or in powder, with syrup or molasses; to be followed, in from four to six hours, by some other cathartic. Sometimes, when it is exhibited with a view to a full action on the liver, gr. j or ij may be given every hour or two until the whole purgative dose is taken; or, it may be administered at bedtime, with an aperient draught the next morning. For children, larger doses are required in proportion than for adults: gr. iij-vj may be given to a child from three to six years old. Calomel occasionally causes griping pain in the bowels, with bilious vomiting; this is attributable, not to any irritable qualities in the medicine, but to the acrid character of the bile secreted. Calomel is an ingredient of the Compound Cathartic Pills.

PILULE HYDRARGYRI (Pills of Mercury), commonly called Blue Pills (see Alteratives), are analogous in their cathartic. action to calomel, but milder. They They are given in about the same doses, and in the same combinations, &c.

HYDRARGYRUM CUM CRETA (Mercury with Chalk), (see Alteratives), combines antacid with mercurial effects. It is a very mild preparation-weaker than even blue pill. It is used as a laxative, in bowel-complaints and other affections of children. Dose, gr. v-xx for adults; for children, gr. ij or iij to viij or x, in powder, and not in pill.

ENEMATA.

In cases of irritability of the stomach-or with the view of hastening the action of cathartics taken by the mouth-or to

remove feculent accumulations in the lower bowels-or to relieve tympanites-or for the purpose of revulsion, cathartic enemata are frequently administered.

When it is desired simply to open the bowels mechanically, tepid water, flaxseed tea, or other demulcent infusion may be employed. The common laxative enema consists of a tablespoonful of common salt, molasses, and lard or olive oil, each, in two-thirds of a pint of warm water; castor oil, or Epsom salt may be added to increase the cathartic effect. Senna tea, or some other cathartic infusion is often employed. To relieve flatulency, oil of turpentine (f3ss to f3j, in emulsion), or milk of assafetida (fzij to fɔ̃iv), may be given. The latter is an excellent preparation in infantile cases.

ORDER III.-DIAPHORETICS.

Diaphoretics (from diapopew, Itranspire), called also sudorifics, are medicines which promote transpiration from the skin. The action of the cutaneous exhalants may be increased by various means. The mere introduction of a large quantity of fluid into the system will produce sweating, if the skin be kept warm. Exercise and a warm temperature, by determining a flow of blood to the cutaneous vessels, act in the same way. Nauseants occasion diaphoresis, by relaxing the orifices of the cutaneous vessels; stimulants, by exciting them to increased secretion. Diaphoretics are employed therapeutically, for their evacuant, revulsive, and alterative effects, and to promote absorption. Different classes of diaphoretics are required for different morbid conditions.

1. Nauseating Diaphoretics.—Most of the emetics, in nauseating doses, produce a powerful relaxing diaphoretic action, and are much employed, with this view, in inflammatory cases, when not contraindicated by the presence of gastric irritability. The PREPARATIONS OF ANTIMONY (see p. 195), and IPECACUANHA (see p. 213), are chiefly resorted to as nauseating diaphoretics. Ipecacuanha is often given as a diaphoretic, in combination with opium, in the form of Dover's Powder (see p. 51).

2. Refrigerant Diaphoretics.-The saline and ethereal preparations classed as refrigerants (see p. 201), produce a gentle relaxing diaphoretic action, unattended with nausea. They are used to allay febrile excitement.

3. Stimulating Diaphoretics.-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 officinalis and other species of Smilax (Nat. Ord. Smilacea), twining, prickly shrubs of Mexico, Guatemala, and the warm countries of South America. The roots consist of numerous wrinkled, slender pieces, of the average thickness of a writing quill, several feet long, springing from a common head or rhizome, and are frequently found in the shops with portions.