Hedera. Ivy. Hedera helix.
Hedera. Hedera Helix L. Ivy. (Fam. Araliaceae.)—This well-known evergreen creeper ia a native of Europe. The fresh leaves have a balsamic odor, especially when rubbed, and a bitterish, harsh, unpleasant taste. They are used for dressing issues, and, in the form of decoction, have been recommended in sanious ulcers and cutaneous eruptions, particularly tetter and the itch. The berries, which have an acidulous, resinous, somewhat pungent taste, are said to be purgative and even emetic. Vandamme and Chevallier discovered in ivy seeds a peculiar very bitter alkaline principle, hederine. It is obtained by treating the seeds with calcium hydroxide, dissolving the precipitated alkaloid in boiling alcohol, and evaporating the alcoholic solution. (A, J. P., xiii, 172.) Posselt has discovered two acids in the seeds, one of which has their taste in a high degree, and was named by him hederic acid, the other he did not obtain quite pure. (See Chem. Gaz., 1849, 93.) The seeds were also found to contain a variety of tannic acid, turning ferric salts dark green, to which Posslet gave the name of hedera-tannic acid. (Ann. Ch. Ph., lxix, p. 62.) Moore (J. P. Ex. T., 1913, iv) has separated a sapo-glucoside which he names hederin. This is not poisonous when taken by the mouth, but when injected intravenously causes death by respiratory paralysis. Davies and Hutchinson confirmed the existence of Posslet's hederic acid, and gave it the formula C16H26O4. Kingzett believes that it is not an acid, but a glucoside. J. Vernet (Ber. d. Chem. Ges., xiv, 685) obtained a glucoside, which separated from solution in boiling acetone, in silky needles, melting at 233° 0. (451.4° F.), insoluble in water, chloroform, and ligroine, slightly soluble in cold acetone, benzene, and ether, more soluble in hot alcohol and hot alkalies. Its formula he gives as C32H54O11, and states that it decomposes on heating with diluted sulphuric acid into a body, C26H44O6, which fuses at from 278°-280° C. (532.4°-536° F.), and a non-fermentable sugar which reduces Fehling's solution. (Y. B. P., 1877, 508.) Later, Van der Haar isolated two glucosides, hederin, C42H66O11, and hederagenin, C31H50O4. (A. Pharm., 1912, 424.) From the trunks of old ivy plants, growing in the south of Europe and the north of Africa, a resinous substance exudes through incisions in the bark, which has been employed in medicine under the name of ivy gum. It is in pieces of various sizes, of a dark yellowish-brown color internally, of a vitreous fracture, pulverizable, yielding a lively orange-yellow powder, of a peculiar not disagreeable odor when heated or inflamed, and of a bitterish resinous taste. Its chief constituent is resin, though some pieces contain a considerable proportion of bassorin, and other large quantities of ligneous matter. It was formerly used as a stimulant and emmenagogue, but is now scarcely employed. Placed in the cavities of carious teeth, it is said to relieve toothache. The light and porous wood of the ivy is sometimes used for making issue-peas.