The people of the Berber upon the Nile make a curious application for the tar they obtain from the fruit. The latter is heated in an earthen vessel with a hole in it; the tar drips through to another vessel and is fit for smearing leather water-bags. The bad smell of the tar (and of the leaves) prevents the camels from cutting open the water-bags.[1135]
Substitutes—Cucumis trigonus Roxb. (C. Pseudo-colocynthis Royle), a plant of the plains of Northern India, with spherical or elongated, sometimes obscurely trigonous, bitter fruits, prostate rooting stems, and deeply divided leaves, resembles the colocynth gourd and has been mistaken for it. Another species named by Royle C. Hardwickii, and known to the natives of India as Hill Colocynth, has oval oblong bitter fruits, but leaves entirely unlike those of the Citrullus Colocynthis.
UMBELLIFERÆ.
HERBA HYDROCOTYLES.
Indian Hydrocotyle, Indian Pennywort; F. Bevilacqua.
Botanical Origin—Hydrocotyle asiatica L., a small creeping herb,[1136] with slender jointed stems, common in moist places throughout tropical Asia and Africa, ascending in Abyssinia to elevations of 6,000 feet. It also occurs in America from South Carolina to Valdivia, in the West Indies, the islands of the Pacific, New Zealand, and Australia.
History—Hydrocotyle is called in Sanskrit mandūka-parnī, in Hindi khulakhudi. The former name denotes various plants, but is thought to refer in Susruta to the plant under notice (Dr. Rice). It was known to Rheede[1137] by its Malyalim name of Codagam (or Kutakan), and also to Rumphius.[1138] It has been long used medicinally by the natives of Java and of the Coromandel coast. In 1852, Boileau, a French physician of Mauritius, pointed out its virtues in the treatment of leprosy,[1139] for which disease it was largely tried in the hospitals of Madras by Hunter[1140] in 1855. It has since been admitted to a place in the Pharmacopœia of India.
Description[1141]—The peduncles and petioles are fasciculed; the latter are frequently 2½ inches long; the peduncles are shorter and bear a 3-or 4-flowered simple umbel with very short rays. The leaves are reniform, crenate, ½ to 2 inches in longest diameter, 7-nerved, glabrous, or when young somewhat hairy on the under side. The fruit is laterally compressed, orbicular, acute on the back; the mericarps reticulated, sometimes a little hairy, with 3 to 5 curved ribs; they are devoid of vittæ. The main root is an inch or two long, but roots are also thrown out by the procumbent stem.
When fresh, the herb is said to be aromatic and of a disagreeable bitter and pungent taste; but these qualities appear to be lost in drying.
Chemical Composition—An analysis of hydrocotyle has been made by Lépine, a pharmacien of Pondicherry,[1142] who found it to yield a somewhat peculiar body which he called Vellarin, from Valālrai, the Tamil name of the plant, and regarded as its active principle. Vellarin, which is said to be obtainable from the dry plant to the extent of 0·8 to 1·0 per cent., is an oily, non-volatile liquid with the smell and taste of fresh hydrocotyle, soluble in spirit of wine, ether, caustic ammonia, and partially also in hydrochloric acid. These singular properties do not enable us to rank vellarin in any well-characterized class of organic compounds.