The authors of the Parmacographia say:— "By exhausting the seeds dried at 100° C. with boiling ether, we obtained a thick light-brownish oil having an acrid taste and concreting below 18° C. The powdered seeds
yielded of this oil 14.4 per cent. Water removes from the seeds a considerable amount of mucilage, some albuminous matter, and a little tannic acid. The first is soluble to some extent in dilute spirit of wine, and may be precipitated therefrom by an alcoholic solution of acetate of lead.
"The active principle of Kaladana is a resin, soluble in alcohol, but neither in benzol nor in ether. From the residue of the seeds after exhaustion by ether, treatment with absolute alcohol removed a pale yellowish resin in quantity equivalent to 8.2 per cent, of the seed. Kaladana resin, which has been introduced into medical practice in India under the name of Pharbitisin, has a nauseous acrid taste and an unpleasant odour, especially when heated. It melts at about 160° C. The following liquids dissolve it more or less freely, namely, spirit of wine, absolute alcohol, acetic acid, glacial acetic acid, acetone, acetic ether, methylic and amylic alcohol, and alkaline solutions. It is, on the other hand, insoluble in ether, benzol, chloroform, and sulphide of carbon. "With concentrated sulphuric acid, it forms a brownish yellow solution, quickly assuming a violet hue. This reaction, however, requires, a very small quantity of the powdered resin. If a solution of the resin in ammonia after having been kept a short time is acidulated, no precipitate is formed ; but the solution is now capable of separating protoxide of copper from an alkaline solution of the tartrate, which originally it did not alter. Heated with nitric acid, the resin affords sebacic acid.
" From these reactions of Kaladana resin, we are entitled to infer that it agrees with the resin of jalap or Convolvulin. To prepare it in quantity, it would probably be best to treat the seeds with common acetic acid, and to precipitate it by neutralising the solution. We have ascertained that the resin is not decomposed when digested with glacial acetic acid at 100° C, even for a week.
" We have had the opportunity of examining a sample of Kaladana resin manufactured by Messrs. Rogers and Co., Chemists of Bombay and Poona, which we found to agree with that prepared by ourselves. It is a light yellowish friable mass, resembling purified jalap resin, and, like it, capable of being perfectly decolourised by treatment with animal charcoal." (op. cit., 2nd Ed., p. 449.)
837. I. uniflora, Roem and Sch., h.f.b.l, IV. 201.
Habitat :-— Through t India, from Nepal and Khasia to Ceylon ; not common, more frequent in the Deccan Peninsula.
A glabrescent twining herb with creeping stems. Leases petioled, oblong, obtuse, entire. Peduncles axillary, 1-flowered Outer sepals larger than the inner and decurrent on the pedicel. Corolla white, campanulate, hairy on the bands outside. Ovary