Oenanthe. Water Hemlock.

Oenanthe. O. crocata L. Water Hemlock. Water Dropwort. Dead Tongue.—A perennial, umbelliferous, aquatic, European plant, exceedingly poisonous both to man and inferior animals. The root, which has a sweetish not unpleasant taste, is sometimes eaten by mistake for other roots, often with fatal results. The symptoms produced are those of irritation of the stomach, besides failure of circulation, and great cerebral disturbance, indicated by giddiness, convulsions, and coma. (See P. J., 1874, 202.) Externally applied, the root produces redness and irritation of the skin, with an eruption. It is said to be sometimes used empirically as a local remedy in piles. Other species of Oenanthe are poisonous, and the whole genus should be suspected. We have two or three indigenous species. In cases of poisoning, the stomach should be at once evacuated, and symptoms met as they arise. A peculiar resinoid principle, denominated oenanthin, has been found by Gerding in Oenanthe fistulosa L., the common water hemlock of Europe, of which half a grain (0.032 Gm.), given to an adult, produced long-continued irritation of the fauces, and a grain (0.065 Gm.), occasional vomiting. (See A. J. P., xxi, 68.) Poehl (A. E. P. P., 1885, xxxiv, p. 258) claimed to have isolated a toxic principle, to which he gave the name of oenanthotoxin, and assigned a formula of C17H22O5. Tutin, however (P. J., Aug. 26, 1911), asserts that this body is not a pure principle but a mixture of neutral resins of unknown nature. He confirms the conclusions that the resin is an active poison. He also examined the tuberous roots of O. crocata and found triacontane, C30H62, and hentriacontane, C31H64. In the P. J., vol. xvi, 357, is a paper by Henry William Jones upon the recognition of O. crocata in cases of suspected cattle poisoning; he found that the starch granules possessed characters which enabled him to distinguish the tubers from all others.

Oenanthe aquatica Lam. (Oenanthe Phellandrium Lam., Phellandrium aquaticum L.) Fine-leaved Water Hemlock. Water Fennel. Fructus Phellandrii. Wasserfenchel, G. Phellandrie aquatique, Fenouil d'Eau, Fr.—A biennial or perennial, umbelliferous, European water plant, the fresh leaves of which are said to be injurious to cattle, producing a kind of paralysis when eaten. By drying, they lose their deleterious properties. The seeds are from 4 to 5 mm. in length (about 2 mm. broad), ovate-oblong, narrow above, somewhat compressed, marked with ten delicate ribs, and crowned with the remains of the calyx, and with the erect or reverted styles. Their color is yellowish-brown; their odor peculiar, strong, and disagreeable; their taste acrid and aromatic. Among their constituents is a volatile oil, upon which their aromatic flavor depends. By C. Fronefield it has been rendered probable that they contain a volatile alkaloid, analogous to coniine, if it be not coniine itself, for if the powdered seeds are rubbed with solution of potassium hydroxide, the peculiar mouse-like odor of that alkaloid is exhaled. The powder was submitted to distillation with potassium hydroxide, the alkaline liquid obtained was neutralized with sulphuric acid and evaporated to a syrupy consistence, alcohol was added to precipitate the ammonium sulphate, the liquid was then filtered, treated with potassium hydroxide, and again distilled. On the surface of the distillate a yellow oily fluid floated, which was only slightly soluble in water but readily so in ether and alcohol, evinced an alkaline reaction with turmeric paper, and neutralized the acids. (A. J. P., May, 1860, 211.) The ethereal oil of water fennel which is present to the extent of 1 to 2.5 per cent. is a yellow liquid of strong, pleasant characteristic odor and burning taste. It has a sp. gr. of 0.85-0.89 and is dextrorotatory. It contains about 80 per cent. of the terpene phellandrene, C10H16. In overdoses the seeds produce vertigo, intoxication, and other narcotic effects. They have been used in chronic pectoral affections, such as bronchitis, pulmonary consumption, and asthma; also in dyspepsia, intermittent fever, obstinate ulcers, etc. The dose of the seeds, to commence with, is five or six grains (0.32-0.4 Gm.), so repeated as to amount to a drachm (3.9 Gm.) in twenty-four hours. They should be given in powder. Dose, of the alcoholic extract, three grains (0.2 Gm.). (P. J., xii, 591.)

The Dispensatory of the United States of America, 1918, was edited by Joseph P. Remington, Horatio C. Wood and others.