Cassia fistula. Purging Cassia.
Nat. Ord. — Fabaceae, or Leguminosae. Sex. Syst. — Decandria Monogynia.
Fruit, or Pulp of the Pods.
Description. — Cassia Fistula is a large tree growing from twenty to forty feet high, with a trunk of hard, heavy wood, dividing toward the top into numerous spreading branches, and covered with a smooth, ash-colored bark. The leaves are pinnate, alternate, from twelve to eighteen inches long, deciduous. The leaflets are opposite or nearly so, from four to eight pairs, ovate, pointed, smooth, undulated, of a pale-green color, polished on both sides, on short, round petioles, from two to six inches long, and from one and a half to three broad. The flowers are large, fragrant, bright-yellow, on long, slender, smooth pedicels. Racemes axillary, pendulous, simple, one or two feet long. The calyx has five nearly equal, oblong, obtuse, smooth sepals. The corolla consists of five petals, which are oval, unequal, concave, spreading, and waved. The three lower filaments much longer than the others, and having a double curve, but no swelling. Anthers on the three long filaments oblong, opening by two lines on the face, the other seven clavate, with pores at the small end. Ovary filiform, smooth, cylindrical, curved, one-celled, containing numerous seeds. The fruit is a woody, dark-blackish-brown, cylindrical pod or legume, a foot or more in length, and about an inch in diameter, with two longitudinal furrows on one side, and one on the other, divided into numerous cells by thin transverse diaphragms, each containing a single, oval, smooth, shining, somewhat compressed seed, imbedded in a viscid, black, sweetish pulp.
History. — Purging Cassia is a native of Upper Egypt and the East Indies, from whence it is supposed to have been transplanted to other parts of the world. It is found in India, Cochin-China, West Indies, and South America. The fruit is the officinal portion. Those pods are to be selected which are the heaviest, and do not rattle when shaken, as they contain the most pulp, which is the part used. To obtain it, the pods are first bruised, and boiling water is poured on them so as to wash out the pulp ; the decoction is then strained, and evaporated to the proper consistence. The pulp has a faint, nauseous odor, and a sweet, mucilaginous taste; it contains sugar, gum, a substance resembling tannin, a glutinous principle, and a coloring matter soluble in ether, with a small portion of water. When good it should be black and shining ; if kept in a damp place it becomes moldy, and long exposure causes it to tum sour. It keeps longest when preserved in the pod. It is nearly soluble in water, and its active parts are taken up by alcohol.
Properties and Uses. — A mild and effectual laxative, useful in habitual constipation. If administered in large doses it purges, occasioning also nausea, flatulence, and griping. Dose as a laxative, one or two drachms, as a purgative one or two ounces. It is seldom employed except as an ingredient in the confection of senna.