As directed by our officinal code, and as found in the shops of this country, mezereon is the bark of two species of Daphne, namely, D. Mezereum, and D. Gnidium, both small shrubs, growing in Europe, the former abundantly in Great Britain, the latter in the southern parts of the Continent. The bark both of the stem and root is efficient; but it is that of the stem which is most common in our markets.

Sensible Properties and Solubility. The bark is in strips, often several feet in length, about an inch in breadth where broadest, and gradually tapering towards one or both ends. it is covered externally with a grayish or reddish-brown, easily separable epidermis, is whitish on the inner surface, very tough and flexible, and comes to us either folded in bundles, or wrapped in balls. in the recent state, it has a nauseous smell, and an extremely acrid taste; when dried, it is nearly inodorous, but retains much of its acrid taste, which is preceded by a sense of sweetness. it yields its virtues to water and alcohol.

Active Principles

Mezereon contains a peculiar crystallizable principle, of a bitter, rough taste, called daphnin, and an acrid resinoid substance, slightly soluble in water, upon which the irritant properties of the bark depend. it contains also a volatile acrid principle, probably a volatile oil, which is most abundant in the fresh bark, but either escapes, or, as suspected by Vauquelin, is changed into the acrid resin by time. When mezereon is boiled with water, an acrid principle, according to Mr. Squire, escapes with the vapour; but it is not given off when the bark is boiled in alcohol, probably because the temperature is not sufficiently high.

Effects on the System

Mezereon is a powerful local irritant, in its recent state inflaming and vesicating the surface, and, even when dried, producing the same effect, though much more slowly. When swallowed, therefore, it is capable of severely irritating the stomach, and may even prove poisonous by the violence of its local action.

In such doses as not to disturb the stomach, it is supposed to stimulate the secretions, particularly those of the skin and kidneys; and, somewhat more largely given, produces purging, nausea, vomiting, and other signs of gastro-intestinal irritation or inflammation. it is said sometimes to irritate the urinary passages like cantharides; and this can be readily understood, if it be admitted that its acrid principle enters the circulation, and escapes by the kidneys. Though no fatal case of poisoning from the bark, so far as I know, is on record, alarming symptoms have in several instances followed the eating of the fruit, which probably owes its properties to the same acrid principle; and one fatal case at least has occurred in a child. The usual symptoms have been violent vomiting and purging, with severe abdominal pains, and great prostration. in a few instances, cerebral symptoms are reported to have occurred, as drowsiness, giddiness, imperfect vision and dilated pupils, and, in one instance, an approach to insensibility; but the phenomena are not, I think, sufficiently decisive to justify the inference that the medicine possesses narcotic powers; for nothing is more common than the occurrence of cerebral disorder, as a result of great gastric disturbance. (See Am. Journ. of Med. Sci., xxi. 518.)

Therapeutic Application

Of the use of mezereon as a local irritant there will be occasion to speak hereafter. As an alterative it has long been employed in secondary syphilis, chronic rheumatism, scrofulous affections, and chronic cutaneous eruptions. At one time it enjoyed considerable reputation; but at present, little confidence is felt in its curative powers in these or any other complaints; and it is seldom used internally, except as an ingredient of the compound decoction and fluid extract of sarsaparilla. The dose of the bark in powder would be about ten grains; but it is never used in this form. The Edinburgh College retained, in the last edition of their Pharmacopoeia, a Decoction (De-coctum Mezerei, Ed.), made with two drachms of the bark, and half an ounce of liquorice, to two imperial pints (two pints and a half in our measure) of water, boiled down to one-half. The dose was from four to eight fluidounces three or four times a day.