Cassia acutifolia. Senna.
Nat. Ord. — Fabaceae. Sex. Syst. — Decandria Monogynia.
Description. — There are several species of Cassia plant, which are supposed to yield the Senna, as the C. Acutifolia, C. Obovata, C. Elongata, C. Lanceolata, etc. Cassia Acutifolia is a perennial shrub, growing from two to ten feet high, with an erect, woody, smooth, branching, whitish stem. The leaves are alternate and pinnate, with glandless footstalks, and two small, narrow, pointed stipules at the base. The leaflets from four to eight pairs to each leaf, are nearly sessile, oval-lanceolate, acute, oblique at their base, nerved, from half an inch to an inch long, and of a yellowish-green color. The flowers are bright yellow, and in axillary spikes. The ovary is linear, downy, falcate, with a smooth, recurved style. The fruit or legume is pendulous, flat, elliptical, obtuse, membranous, smooth, grayish-brown, bivalved; quite straight, about an inch long, and half an inch broad, and divided into six or seven cells each containing a hard, heart-shaped, ash-colored seed. It grows in great abundance in Upper Egypt, and furnishes the greater part of the Alexandria Senna of commerce.
Cassia Obovata, a perennial, is smaller than the above, growing to the hight of about eighteen inches ; with a stem pubescent at the base, and cylindrical. The leaves are alternate, equally pinnate, smooth, with two subulate, entire, persistent stipules at the base, and with from four to seven pairs of opposite, nearly sessile, obovate, cuneiform leaflets, obtuse but mucronate at the apex, unequal at the base ; the uppermost gradually the largest, slightly pubescent. The flowers are pale-yellow, and in erect, rather loose axillary racemes. The legumes oblong, falcate, membranous, smooth, rounded at each end, with an elevated, interrupted ridge along the middle. The seeds are from six to eight, and heart-shaped. This species grows wild in Egypt, Nubia, Syria, and Senegambia ; and has been cultivated in the West Indies, and many parts of southern Europe. It is very nearly identical with the C. Obtusata of Heyne. This plant furnishes an inferior senna, known as the Italian or Aleppo Senna.
Cassia Elongata, is an annual, but with care it may be made to live through the year, and to assume a suffruticose character. It has a smooth, erect stem, and narrow, equally pinnated leaves with from four to eight pairs of lanceolate leaflets, which are nearly sessile, slightly mucronate, smooth above, rather downy beneath, oblique at the base, with the veins turned inward so as to form a wavy line immediately within the margin of the leaflet ; petioles glandless ; stipules softly spinescent, semihastate, spreading, minute. The flowers are bright yellow, and arranged on erect, stalked, axillary and terminal racemes, rather longer, than the leaves. The legume is pendulous, oblong, membranous, tapering abruptly at the base, rounded at the apex, an inch and a half long, and about half an inch broad, with many deep-brown seeds. It is supposed to grow in southern Arabia, and in the interior of India, and is cultivated at Tinnivelly.
Cassia Lanceolata resembles the above, having, however, never more than four or five pairs of leaflets, oblong, and either acute or obtuse, not at all ovate or lanceolate, and perfectly free from downiness even when young ; the petioles have constantly a small, round, brown gland a little above the base. The pods are erect, oblong, tapering to the base, obtuse, turgid, mucronate, rather falcate, especially when young, at which time they are sparingly covered with coarse, scattered hairs. It grows in Arabia, and was considered by Forskhal as the true Mecca Senna.
History. — These are supposed to be the principal species which yield the Senna, though much uncertainty exists with regard to them, arising from the want of correct specimens, the difficulty attending the investigation of the plants in their places of growth, the ignorance of the influences which a change of locality may exert upon them, and whether the presence or absence of the glands on the petioles are to be assumed as specific characters. Although this confusion exists in the botanical history of senna, yet, in commerce, but three varieties of the drug are found, or which are ever imported into this country, these are, the Alexandrian or Egyptian, which is the finest and most valuable article, the Indian, and the Tripoli Senna.
Alexandria Senna is collected from Sennaar, Nubia, and Upper Egypt, and made up at Boulak, not far from Cairo, under the superintendence of the Egyptian government, from which place it is forwarded to Alexandria, for the European markets. It consists of the leaflets of C. Acutifolia, C. Obovata, pods, broken leafstalks, flowers, etc., likewise the leaves of Cynanchum Oleaefolium, or Solenostemma argel. The harvest for collecting commences in September, at which time the branches of the shrub are cut, and exposed to the sun, until the leaves begin to fade ; they are then collected into bundles, and placed on rocks and high grounds, in order to have full benefit of the air and of the sun's rays. When the leaves are quite dry, the branches are threshed, and the leaves separated from them, they are then packed in sacks and sent to Boulak, at which place their adulteration with other leaves is said to take place.
As received in this country, Alexandria Senna is generally in bales and barrels, and is considered the finest and most valuable variety ; the best and most esteemed is that which contains the least quantity of cynanchum leaves, senna leafstalks and pods, where the entire lanceolate leaves are numerous, and where the odor and taste is strong and pure. It has a peculiar but not disagreeable odor, with an unpleasant, nauseous, mucilaginous, and sweetish taste, with hardly any perceptible bitterness, unless it be adulterated with the leaves of the Argel or Cynanchum oleaefolium which impart bitterness to the powder or infusion, and which is the most important impurity to remove. They may be recognized by having no visible lateral nerves on their under-surface ; by being longer, thicker and firmer than senna leaves,- by the greater regularity of their base, being of a lighter color, of a bitter taste, and often spotted with a yellow, bitter, gummy-resinous incrustation.
Tripoli Senna somewhat resembles the Alexandrian, but is considered much inferior to it ; the leaves are more broken down, and the leafstalks more numerous. It seems to consist of one of the acute leaved species and a slight admixture of C. Obovata, and very seldom contains any adulteration with the argel leaves. There is much uncertainty as to the place from which it is derived.
India or Mocha Senna is of three kinds, the Bombay, the Madras, and the Tinnivelly, of which the first, is usually imported from Bombay, though it comes in the first instance from Mocha and other ports of the Red Sea ; the second and third from Madras ; of these, the Tinnivelly is esteemed the best. India Senna consists mainly of large, thin, unbroken, acute, yellowish-green leaves, seldom adulterated, and when good, is fully equal to the Alexandrian. There are other varieties, but they seldom reach this market.
Good Senna may be known by the bright, fresh, yellowish-green color of the leaves, with a faint and sickly odor somewhat similar to green lea, and a nauseous, mucilaginous, sweetish, and slightly bitter taste ; and the fewer the stalks, seed pods, broken leaves, and dirt, the better is the senna. Its active principles are taken up by cold or warm water, alcohol, and proof spirits ; boiling destroys its virtues unless it be in vacuo, or in a covered vessel. Various analyses have been made of senna, but there are none on which we can satisfactorily rely. M. M. Lassaigne and Feneulle found it to contain a peculiar bitter principle called Cathartin, chlorophylle, fixed oil, a small quantity of volatile oil, albumen, yellow coloring matter, mucilage, malate and tartrate of lime, and acetate of potassa, and some mineral salts. The cathartin is a yellowish-red, uncrystallizable substance, of a peculiar odor, and a bitter, nauseous taste, very soluble in water and alcohol, but insoluble in ether. It is considered to be the purgative principle of the drug, yet this is not universally admitted, as several experimenters deny that it possesses any purgative power whatever. The infusion or decoction of senna is incompatible with strong acids, alkaline carbonates, lime-water, tartar emetic, acetate of lead and tannin, or astringent plants containing tannin. The tartarized antimony and acetate of lead do not precipitate the cathartin.
Properties and Uses. — Senna is r, certain, manageable, and convenient cathartic, very useful in all forms of febrile disease, and other diseases where a violent impression on the bowels is not desired. Its influence is chiefly exerted on the small intestines, augmenting their mucous secretions, exciting increased peristaltic motion, and producing loose brown evacuations. It does not act as a sedative, as is the case with some cathartics, nor as a refrigerant ; but has a slight stimulating influence, insufficient however, to contra-indicate its use in cases of general excitement, or reaction. Beside the nauseating taste of senna, it is apt to cause sickness at stomach, and very few persons can use it alone, without experiencing more or less griping pains. The addition of cloves, ginger, cinnamon, or other aromatics are excellent correctives of these unpleasant effects. A teaspoonful of cream of tartar to a teacupful of the decoction or infusion of senna, is a mild and pleasant cathartic, particularly suited for females where it may be required soon after delivery. The addition of neutral laxative salts is another mode, adopted by a certain class of practitioners, of preventing the tormina, and at the same time of increasing the activity of the infusion of senna, as, phosphate of soda, Epsom, or Rochelle salts ; these are, however, rarely used by Eclectics. Saccharine and aromatic substances are also sometimes combined for this purpose, as sugar, manna, aromatic seeds, electuary of senna, etc. The purgative effect of senna is much increased by the addition of the pure bitters ; the decoction of guaiacum is said to answer a similar purpose. Senna is contra-indicated in an inflammatory condition of the alimentary canal, hemorrhoids, prolapsus ani, etc. The dose in powder is from thirty to fifty grains ; in tincture, from half a fluidounce to two fluidounces ; electuary, two drachms ; and of the infusion, which is the most usual mode of administration, from two to four fluidounces.
A preparation termed Cassine, said to be the active principle of the Alexandria Senna, is advertised as a preparation of an eastern manufacturing establishment. It is stated to be a whitish-brown powder, of a slightly bitter taste, a senna-like odor, soluble in water and insoluble in alcohol. I have not seen it, nor have I been able to obtain its mode of preparation.
Off. Prep. — Enema Sennae Composita; Extractum Rhei et Sennae Fluidum ; Extractum Spigeliae et Sennae Fluidum ; Extractum Sennae et Jalapee Fluidum ; Infusum Sennae ; Pulvis Jalapae Compositus ; Tinctura Sennae Composita.