water, and taken with the addition of rock salt and ginger or sugar and black pepper. Roxburgh wrote in his Flora Indica of this drug that " the bark of the root is by natives employed as a purgative, for which they use it fresh, rubbed up with milk. About 6 inches in length of a root, as thick as the little finger, they reckon a common dose."
Mr. T. N. Mukharji suggests that the uncertain action of the drug, purchased from the bazar, may be due to the admixture of the roots of Ipomœa bona-nox. The two roots, when dry, cannot be easily distinguished from each other. The plants, however, though resembling each other, can be easily identified. I. bona-nox has a round stem, while that of I. Turpethum is ribbed. The flowers and seeds of I. bona-nox are also larger than those ofI. Turpetham.
Turpethin, C76H128O36 , the glucoside of the roots of Ipomœa turpetham, is an amorphous, yellow powder, colourless, in thin layers, and melts at 146.8° (corr); it has a rotatory power of— 30.14°, and is sparingly soluble in chloroform, soluble in alcohol and acetic acid. When treated with alkalis, it yields turpethic acid, a yellow, hygroscopic mass. By oxidation with nitric acid, turpethin yields oxalic, isobutyric, and sebacic acids and carbonic anhydride, whilst potassium permanganate oxidises it to oxalic, isobutyric, and turpe-tholic acids. When hydrolysed with mineral acids, it yields isobutyric acid (1 mol.), turpethole, C16H30O (? C16H300) 3 , a substance forming feathery, interlaced crystals and melting at 85.76° (1 mol), glucose (3 mols.), and a viscid, liquid acid, which was not isolated, but gave a silver salt, C15H27O5 Ag,
Turpetholic acid, C16H32O4 is obtained, as mentioned, and also by the action of alkalis or their carbonates on turpethole. It forms a hard, white, crystalline mass, melts at ,88.4°, and is soluble in alcohol, sparingly soluble in ether ; turpethole seems to be the anhydride of turpetholic acid.— J. Ch. S. 1893, A. I. 424.
Turpethin is identical with jalapin in percentage composition ; when treated with baryta water, turpethic acid is formed, which is colourless and not volatile with steam.— J. Ch. S. 1896, A. I. 38.
The rhizome contains a glucosidal resin, named turpethein, soluble in pure ether. This is separable by light petroleums spirit into a soluble glucoside, a— turpethein, and a sparingly soluble body, b— turpethein. a— Turpethein is soluble in baryta water, and yields, when hydrolysed, the non-volatile fatty hydroxy-acid, C16H32O3 , identical or isomeric with jalappinio ipomeolic, and tampicolic acids. It also yields a volatile fatty acid of C5 series, probably one of the valeric acids. The sugar formed is rhamnose. b— Turpethein, when hydrolysed, gives a non-volatile, higher fatty acid, rhodeose, and dextrose.— [J Ch. I. May 31, 1907, p. 550],