As laxatives, we employ the sena (cassia sena); ipecacuanha (callicocca ipecacuanha) in decoction; the polypody root and myrobolans (polypodium vulgaris et emblica); the damask rose leaves (rosa damascena); rhubarb (rheum palmatum); purging flax (linum ca-tharticum); broom (spartium scoparium); mechoacanna (convolvulus mechoacanna); buckthorn berries (rham-nus catharticus); jalap (convolvulus jalapa); rattlesnake root (polygala seneka); celandine root (chelido-nium majus); black alder (rhamnus frangula); scam-mony (convolvulus scammonia); common and dwarf elder, inner bark (sambucus nigra et ebulus). from the mineral kingdom laxative cathartics are, James's powder, calomel, and phosphat of silver.

These substances act with greater or less acrimony; and those towards the end of the list are often highly acrid. Many others might be enumerated, which are found in the writers on the Materia Medica, and which occur in their places in this dictionary. From these before him, however, the practitioner may have a sufficient choice. In general, these laxatives excite colic, and sometimes prove emetic: they frequently stimulate the system, increase the heat and the pulse; but, on the other hand, they are active and effectual evacuants. If an opiate has previously produced some relaxation in the cells of the colon, they will bring away the most hardened, long retained scybala. In cases of fever, however, these are often only evacuated when the relaxation is produced by the solution of the disease. Mild purgatives will, in those cases, discharge what had escaped the action of the most violent. The former part of this list contains the chologogues of the ancients.

The drastics are the gamboge (stalagmitisof Koenig); wild cucumber (momordica elaterium); bitter cucumber (cucumis colocynthis); black and white hellebore (helle-borus niger, and veratrum album); sea colewort (bras-sica marina, soldanella pharmaceut.); resin of jalap, nitrat of silver, and various mercurials and antimo-nials, q. v.

These drastics act with great violence, generally disorder the stomach and the whole system in a considerable degree, and sometimes inflame the intestines. These, and some of the more active medicines of the former group, were chiefly used by the ancients, for the milder laxatives were introduced by the Arabians, and occasioned the numerous cautions respecting the use of purgative medicines. From this circumstance also, and from the use of mercurials as laxatives, the supposed necessity of confinement to a warm room apparently arose. This measure may be dictated by convenience; but certainly warm air, and a horizontal posture, retard or lessen the operation of laxatives.

The narcotic cathartics remain, which disorder the senses, produce stupefaction, and seem to act as cathartics, by the general commotion that they produce. We think these effects in some measure follow the use of the gutta gamba, the colocynth, the hellebores, and some of the other drastics, when first introduced into the stomach. They often occasion sickness, faintness, and cold sweats; but the cathartics more decidedly sedative are the tobacco (nicotiana tabacum), the foxglove (digitalis purpurea), and the lactuca virosa. One effect of the drastics, which we deferred mentioning till we had introduced this last group, is the discharge of water from the cavity of the peritoneum, the chest, and the cellular substance. This effect seems to arise from the sedative power of the remedies. In this moment of total relaxation every bond of union is removed, even the inosculation of the maternal and foetal parts of the placenta, every form of obstruction recedes: the secretory organs yield, not from the action of the remedy increasing the excitement, but from the temporary solution of the tonic power.

We have little to add to what we have already said of eccoprotics. A mild vegetable diet is the safest and the best. Aloes, combined either with the foetid gums or soap, is highly useful, chiefly from its very slow decomposition in the small intestines. Sulphur is equally convenient, from the same cause. The sea water and the purging mineral waters are also highly useful, when they can be conveniently taken. Rhubarb we have found too irritating, unless combined with soap; and a sufficient quantity of the"latter renders the bulk inconvenient. We have generally added a small proportion of the scammony, to render it more active. Aloes is by far more useful; and though it sometimes produces piles, yet, in the forms above mentioned, we have not experienced this inconvenience. Dr. Fordyce, in an excellent paper "on the combination of medicines," recommends a compound eccoprotic, which he thinks of superior efficacy to any other. It consists of five parts of aloes, three of sagapenum, two of gamboge, and one of distilled oil of camomile. Two parts of gum arabic are employed to give it a consistence, and the whole is made into a mass with the syrupus a spina cervina. From six to ten grains are a dose; and it is said to operate without sickness or griping. We shall resume this subject under the article of combination of medicines, and shall then speak of the advantages derived from the union of different purgatives.

One other class of purgatives remains, viz. what are styled, by some late authors, "the mechanical;"consisting chiefly of watery liquors. These act by their bulk, which is the chief stimulus of every hollow muscle. The utility of a large bulk of fluids is particularly conspicuous in clysters, where a pint and a half of milk and water will procure a motion, often more readily than the most active purgative administered in the same manner. We speak, however, of these mechanical cathartics, chiefly to notice the effects of dilution in increasing the power of the neutral salts. If an ounce is the proper dose in two ounces of water, two thirds will be sufficient in half a pint; and perhaps one half in a pint. This fact, before alluded to, solves the difficulty felt in accounting for the purgative power of some mineral waters, in which the proportion of salts is inconsiderable.