SENNA is one of the most important purgatives contained in our materia medica. Two sorts of senna are recognized in the pharmacopceia—viz., Alexandrian senna and Tinnevelly senna. The Alexandrian senna leaves are chiefly obtained from Cassia hot ceolata, while the Tinnevelly senna leaves are yielded by Cassia elongate. Alexandrian senna is chiefly grown in Nubia and Upper Egypt, and is imported in large bales from Alexandria. It is apt to he adulterated largely with the flowers, pods, and leaves of Cynanchnin ar,ghel and 7ephrosia sponiuv. Tinnecelly or East Indiansenna in odor and taste entirely resembles Alexandrian senna. The leaflets are, however, "about 2 in. long, lanceolate, acute, unequally oblique at the base, flexible, entire, green, without any admixture." – Senna is, as Dr. Christison observes in his Dispensatory, certain, so manage able, and so convenient a purgative, that few remedies of its class are held in equal estimation. In point of energy, it holds a middle place between the mild laxatives and drastic cathartics. It acts chiefly on the small intestines, increasing their mucous secre, Lion, as well as their peristaltic motion, and producing loose brown evacuations," The drawbacks to its more universal administration are its disagreeable taste, and its ten dency to produce nausea, griping\ and flatulence; the means of correcting which are subsequently noticed. The only circumstance positively eontfa-indicating its employ ment is an inflammatory state of the intestinal mucus membrane. Although serum has been frequently submitted to chemical analysis, its active principle is not known; but whatever the cathartic principle may be, it is obviously absorbed into the circulation before it begins to operate, since this drug imparts a purgative property to the milk of nurses.
The following are the most important preparations of this medicine: 1. Infusion of Senna, which is obtained by infusing for one hour, and then straining, half an ounce of senna and half a dram of sliced ginger in half a pint of boiling water. The taste of thig infusion is much concealed by the addition of some black tea, or what Neligan finds "still better, coffee, and it may be sweetened with sugar, and milk added; it is in this way readily taken by children." The addition of neutral laxative salts checks the griping, which is often caused by senna alone, and at the same time increases its activity. The ordinary black draught is commonly prepared by adding one ounce of sulphate of magnesia to four ounces of infusion of senna. Two or three ounces of this mixture, to which a dram each of the tinctures of semis and of cardamoms may be added, usually act as a very useful aperient.
2. Tincture of Senna, composed of senna, raisins, caraway seeds, and coriander seeds macerated in proof-spirit, and formerly known as elixir salutis, or the elixir of health, is seldom given alone. Christison recommends a mixture of an ounce of the tincture of senna with an ounce and a half of sulphate of magnesia, dissolved in four ounces of water, and as much infusion of roses. "A wine glassful of this given every hour seldom fails to
act with energy, and without sickness or tormina, and is an excellent combination for most febrile disorders." The tincture is, however, most commonly prescribed in closes of one or two drains, as an adjunct to other cathartic mixtures, to correct their grip ing properties.
3. Confection of Senna, commonly known as lenitive &ciliary, is a pulpy mixture of powdered senna with powdered coriander seeds, figs, tamarinds, cassia pulp, prunes, extract of liquorice and sugar; all of which substances are, under certain specified con ditions, combined by the action of boiling water. When properly prepared, which is often not the case, it it forms a mild aperient, well suited for persons suffering from piles.
In the above preparations, it is immaterial whether Alexandrian or East Indian senna is employed.
The senna leaves of commerce and of medicine are the produce of several species of Cassia (q.v.). natives of India, Arabia, Syria, and the u. of Africa. Cassia aloud(' is a herbaceous 1 lint 1 to 2 ft. high, having Emcoth leaves, 6 or 7 pair of obovate obtuse leaflets, racemes of yellow flowers, and curved, compressed pods, with an inter rupted ridge along the middle of each valve. It is found in Egypt and Nubia, and is now also cultivated in Italy, Spain, the West Indies, etc. 'C. ac-ufifolia is a half-shrubby plant, about 2 ft. high, with racemes of yellow flowers, lanceolate acute leaves, and flat elliptical pods, somewhat swollen by the seeds. It grows in the deserts near Assouan, and the leaves are collected by the Arabs, and carried by merchants to Cario for sale.— C.
elongata is an annual with erect, smooth stem; narrow leaves, with 4 to S pair of lanceolate leaflets, which are rather downy beneath; racemes of yellow flowers; and oblong pods, quite straight, rounded at the apex, and tapering to the base. It grows in India.—C. athiopica is about 18 in. high, with 3 to 5 pair of oval-lanceolate, downy leaflets; the pods flat and smooth. It grows in the n. of Africa.—C. lanccolata is an Arabian species, differing from the others in its erect pcds.—All these seem to furnish the officinal senna. Linnaeus, not aware of the diversity of species, assigned it to one which lie named C. senna, but it would he hard to say which has a preferable claim to this name., All the species have the leaflets unequabsided, by which they arc readily distinguished from other leaflets often used for the adulteration of senna, as those of angel v.) and Madder senna, The commercial names of the different kinds of senna do not seem in general to correspond with differences of species, but rather to refer to the countries or ports from which they are brought.