in botany: A genus of the monogynia order, belonging to the decandria clas of plants; and in the natural method ranking under the 33rd order, Lomentaceae. The calyx is pentaphyllous; petals five; anthers upper, three barren; lower, three-beaked; a leguminous plant. There are 30 species, all of them natives of warm climates. The most remarkable are,

1. The fistula or purging cassia of Alexandria. It is a native of Egypt and both Indies, where it rises to the height of 40 or 50 feet, with a large trunk, dividing into many branches, garnished with winged leaves, composed of five pair of spear-shaped lobes, which are smooth, having many transverse nerves from the midrib to the border. The flowers are produced in long spikes at the end of the branches, each standing upon a pretty long foot-stalk; these are composed, like the former, of fine yellow concave petals, which are succeeded by cylindrical pods from one to two feet long, with a dark brown woody shell, having a longitudinal seam on one side, divided into many cells by transverse partitions, each containing one or two oval, smooth, compressed seeds, lodged in a blackish pulp, which is used in medicine. There are two sorts of this drug in the shops; one brought from the East Indies, the other from the West: the canes or pods of the latter are generally larger, rough, thick-rinded, and the pulp nauseous; those of the former are lefs, smoother, the pulp blacker, and of a sweeter taste; this sort is preferred to the other. Such pods should be chosen as are weighty, new, and do not make a rattling noise (from the seeds being loose within them) when shaken. The pulp should be of a bright shining black colour, and a sweet taste; not harsh, which happens from the fruit being gathered before it has grown fully ripe, or sourish, which it is apt to turn upon keeping: it should neither be very dry nor very moist, nor at all mouldy; which, from its being kept in damp cellars or moistened, in order to increase its weight, it is very subject to be. Greatest part of the pulp dissolves both in water and in rectified spirit; and may be extracted from the cane by either. The shops employ water, boiling the bruised pod therein, and afterwards evaporating the solution to a due consistence. This pulp is a gentle laxative medicine, and frequently given, in a dose of some drams, in colic habits. Some direct a dose of two ounces or more as a cathartic, in inflammatory cases, where the more acid purgatives have no place; but in these large quantities it generally nauseates the stomach, produces flatulencies, and sometimes gripings of the bowels, especially if the cassia be not of a very good kind: these effects may be prevented by the addition of aromatics, and exhibiting it in a liquid form. Geoffroy says, it does excellent service in the painful tension of the belly, which sometimes follows the imprudent use of antimonial; and that it may be advantageously acuated with the more acid purgatives, or antimonial emetics, or employed to abate their force. Vallisnieri relates, that the purgative virtue of this medicine is remarkably promoted by manna; that a mixture of four drams of cassia and two of manna, purges as much as twelve drams of cassia or thirty-two of manna alone. Sennertus observes, that the urine is apt to be turned of a green colour by the use of cassia: and sometimes, where a large quantity has been taken, blackish. This drug gives name to an officinal electuary, and is an ingredient also in another.

2. The cassia fenna is a shrubby plant cultivated in Persia, Syria, and Arabia, for the leaves, which form a considerable article of commerce. They are of an oblong figure, sharp-pointed at the ends, about a quarter of an inch broad, and not a full inch in length, of a lively yellow with green colour, a faint not very disagreeable smell, and a subacid, bitterish, nauseous taste. They are brought from the above places, dried and picked from the stalks, to Alexandria in Egypt, and thence imported into Europe. Some inferior sorts are brought from Tripoli and other places; these may easily be distinguished by their being either narrower, longer, and sharper pointed; or larger, broader, and round pointed, with small prominent veins; or large and obtuse, of a fresh green colour, without any yellow cast. Fenna is a very useful cathartic, operating mildly, and yet effectually; and, if judiciously dosed and managed, rarely occasioning the ill consequences which too frequently follow the exhibition of the stronger purges. The only inconveniences complained of in this drug are, its being apt to gripe, and its nauseous flavour. The griping quality depends upon a resinous substance, which, like the other bodies of this class, is naturally disposed to adhere to the coats of the intestines. The more this resin is divided by such matters as take off its tenacity, the less adhesive, and consequently the less irritating and griping it will prove; and the less it is divided, the more griping: hence fenna given by itself, or infusions made in a very small quantity of fluid, gripe feversely, and purge less than when diluted by a large portion of suitable menstruum, or divided by mixing the infusion with oily emulsions. The ill flavour of this drug is said to be abated by the greater water-sigwort; but we cannot conceive that this plant, whose smell is manifestly fetid and its taste nauseous and bitter, can at all improve those of fenna; others recommend bohea tea, though neither has this any considerable effect. The smell of fenna resides in its more volatile parts, and may be discharged by lightly boiling infusions of it made in water: the liquor thus freed from the peculiar flavour of the fenna, may be easily rendered grateful to the taste, by the addition of any proper aromatic tincture or distilled water. The colleges both of London and Edinburgh have given several formulae for the exhibition of this article, such as those of infusion, powder, tincture, and electuary. The dose of fenna in substance, is from a scruple to a dram: in infusion, from one to three or four drams. It has been customary to reject the pedicles of the leaves of fenna as of little or no use: Geoffrey however observes, that they are not much inferior in efficacy to the leaves themselves. The pods or seed-vessels met with among the fenna brought to us, are by the college of Brussels preferred to the leaves: they are less apt to gripe, but proportionally less purgative.

*Cassia-Lignea.* See *Laurus.*