Senna (FR., Shit:; GER., Sennes).—The leaves of two species of Cassia are very widely used as a purgative. The species are :—(1) C. aeutifolia, indigenous to many parts of Nubia—as Sukkot, Mhos, Dongola,and Berber—Sennar, and Kordofan, as well as Timbuctu, and Socetc ; it yields "Alexandrian" aenna. (2) C. ,trigustifolia, abundant in S. Arabia—Yemen and Hadramaut—also in Somali-land, Sind, and the Punjab (in the two lest, it is cultivated); the wild (Arabian) plant yields "Bombay" or " Mocha " Benno, and the cultivated (Indian) plant, " Tinnevelly " aenna. The Nubian peasants collect two crops of senna-leaves annually : the first and chief harvest takes place after the rains (September); the second, and very insignificant, during the dry season (April). The operation consists in felling the shrubs, and placing them to dry on the scorching hot rocks. When dry, the leaves are packed in bags of palm-leaf, holding about I quintal (nearly 2 ewt.), sent by camel caravans to Darno and Es-souan, and thence by water to Cairo. Some "mountain senna " (C. acutifolia) is said to pass via Massowa and Suakin to Cairo and Alexandria. " Indigenous," or " wild," sauna (C. obovata) grows in the durra-fields; but it was never esteemed, and ie only rarely imported from Tripoli. Within the last few years, some fine cultivated samples of this Benne have been received from Barcelona. To return to the commercial varieties—Alexandrian mina arrives in largo bake; latterly it is found in very fair condition, but formerly it was always dirty, and mixed with stems, flowers, stones, and the leaves, flowers, and fruits of Solenostemma Argel; the latter was, indeed, deliberately added, and found favour with some, but as the leaves occasion griping without purging, they should be avoided—the leaves are easily distinguished from Klima by their minutely wrinkled surface. The value of this kind varies between 3id. and le. 6d. a lb.
" Bombay," " E. Indian," " Arabian," or "Mocha" mime, is collected in S. Arabia, and shipped from Red Sea ports to Bombay, and thence to Europe; it is of very low quality, chiefly on account of careless preparation, as it is not adulterated ; its value is i--2id. a lb. " Tinnevelly " scum is a superior and carefully prepared drug, shipped from Tuticorin (S. India) ; its price is 1 id.-Is. 6d. a lb.
Very fine senna has been grown in Rockhampton, Australia ; and it is confidently stated that tho culture of the plant might be profitably undertaken in the fern-tree ranges of Victoria.
Snake-root (Virginian), or Serpentary (FR., Serpentaire de Virginie ; GER., ScIdangcn trurzel).—An infusion or tincture of the root of A ristolochia Serpentaria is prescribed as a stimulating tonic and diaphoretic, generally with cinchona ; it is not now used against anuke-bite. The plant is a native of the New World, growing in shaded forests, from Indiana and Missouri to Virginia and Florida, especially in the Allegheny and Cumberland ranges. The root has a dull-brown colour, an aromatic odour, and a bittorish-aromatic flavour. It is imported in bales, casks, and bags, from Boston and New York ; its value is about 10d.-1s. a lb. The roots of Spigelia Marilandica and Cypripedium pubescens are sometimes accidentally mixed with it.