This plant, like several others of the same genus, owes its medicinal activity to the presence of chrysophanic acid, sometimes called Rhein, form C14H6O2″(O.H.2 ) This substance belongs to the anthracene group of carbon compounds, and, like alizarin, is regarded as dioxyan thraquinone, C14H6O2″ jofrr- It crystallizes in six-sided prisms, is tasteless, and may be sublimed without decomposition ; it is contained in Goa powder (50 per cent.), rhubarb, most varieties of dock, Lichen orcella, Permelia parietina, Cassia alata, C. occidentalis, C. Tora, &c. As met with in commerce, it is in the form of a light-yellow poder, soluble in benzol, chloroform, turpentine, and in the fixed and volatile oils to a large extent, sparingly soluble in ether and alcohol, and insoluble in water, glycerine, and in solid paraffin. It is dissolved by sulphuric and nitric acids (in the latter to a less extent), by caustic
potash and by ammonia ; fuses at 123°3 C, and boils at 232°2 C. At the latter temperature it is decomposed into a dark-green resinous substance, which is largely soluble in ether. Oil Jecoris dissolves twice its weight of the acid, yielding a mixture containing 70 per cent. Oil olivæ, Oil Pini sylvest., Creasotum, Oil Terebinth., Oil Lavand., and Vaseline, dissolve readily their own weight of acid, yielding mixtures containing 52 per cent.
" Taking advantage of its solubility in the fixed oils, a considerable saving may be effected by preparing ointments direct from Araroba. Oil olivæ thoroughly exhausts that substance, yielding the acid after removal of the oil by ether in a state of purity. The Singhalese doctors take advantage of this fact, and fry the leaves of Cassia alata, 0. Tora, C. occidentalis, and C. Sophera in gingelly or castor oil. The strained product is used as an ointment for ring-worm and other skin diseases." (F. Laker Macmillan, Phar. Journ., 15th March 1879.)
420. C. obtusifolia, Linn, h.f.b.i., ii. 263.
Syn. : — Senna Tora and toroides, Roxb. 351.
Eng. : — The fœtid Cassia.
Sans. : — Prabúnátha, dádamari, dádmadan.
Vern. : — Chakundá, panevár (H. & B.) ; Chakaoda arak. (Santal) ; Pawár, panwar, pawás. chakunda (Pb.); Panwar (N.-W.P.) takálá, tarotá, táklá, tánkli (Mar.) ; Kawário, kovariza (Guz.) ; Tánkalá, kowaria (Bom.) ; Tarota (Duk.) ; Ushittagarai, tarotak (Tam.); Tagarisha-chettu (Tel.).
Habitat : — Found everywhere in Bengal, and widely spread throughout India.
An annual weed growing up into an undershrub. Leaves distinctly petioled, furnished with glands on the main rachis between the leaflets ; glabrous. Leaflets 6, ovate-oblong, perfect, glaucous, membranous, l-l½in. Stipules large, linear sub-
