THYMELACEjE. 561 



of the epidermis, it is greenish ; internally it is white and fibrous. The taste 

 is at first somewhat sweetish, but soon becomes very acrid and unpleasant ; 

 in a fresh state, the smell is nauseous ; but when dried, it is inodorous. It 

 yields its properties to water and alcohol. Several analyses have been made 

 of this and other species, and they are shown to owe their active qualities to 

 the presence of an acrid resin and a peculiar crystalline principle, discovered 

 by Vauquelin, to which he gave the name of Daphnin. It is colourless and 

 transparent, crystallizes in aggregated prisms, very soluble in water, alcohol, 

 or ether, is inodorous, and of an acrid taste. Gmelin and Bar consider that 

 it is analogous to asparagin, and that when pure, it has very slight powers. 

 The active principle is evidently, as is stated by Vauquelin, an essential oil, 

 which is either changed into .a resin, or is in combination with it. This oil 

 is partially volatile, for Mr. Squire (Pharm. Trans. Lond.) says, that the 

 pungent odour given off by boiling the root, is so powerful as to produce great 

 irritation. 



Medical Properties: — When applied to the skin, the Mezereon, especially 

 in a fresh state, acts as a topical irritant and vesicant. When taken inter- 

 nally in large doses, it operates as a violent irritant poison, but in moderate 

 doses promotes the action of the secernent organs, especially the kidneys and 

 skin. From its irritating powers, it sometimes increases the peristaltic power 

 of the intestines, and it is stated by Vogt that it. occasionally affects the cere- 

 brospinal system. 



It is seldom administered alone, being generally given in combination with 

 sarsaparilla and other articles, as an alterative and diaphoretic, in chronic 

 cutaneous, venereal, rheumatic, and scrofulous affections. Dr. Russell [Med. 

 Obs. and Inquir. iii. 194) recommended a decoction of this bark in venereal 

 nodes and pains in the bones ; and this opinion of its powers as a deobstruent 

 in inveterate syphilitic cases being supported by Drs. Monro, Fothergill, and 

 Home, it was considered as capable of curing that disease, even where mer- 

 cury had failed, until the experiments and observations of Mr. Pearson (Obs. 

 on various articles of the Mat. Med. 1800) demonstrated that it had not the 

 power of removing the venereal affection in any one stage or form. In con- 

 sequence of these remarks, its reputation rapidly declined, and it is now sel- 

 dom employed in these cases, except as a component of the compound decoc- 

 tion of sarsaparilla. Cullen prescribed it with some success in chronic cuta- 

 neous diseases, and further experience has shown that it may be beneficially 

 used in these, as well as in some forms of scrofula and chronic rheumatism. 



Topically, it has been applied with some success as a sialagogue in tooth- 

 ache and in paralysis of the throat. It is also much employed in France and 

 Germany as a vesicatory. 



Several other species of Daphne are used as substitutes for the Mezereon, 

 or even preferred to it ; of these the D. gnidium and D. laureola are the 

 most generally resorted to, as possessing identical properties, but from the 

 experiments of Mr. Squire, it would appear that the mezereum is the most 

 active, both in the degree and duration of its stimulating effects. It may be 

 noticed that where it is necessary to powder these barks, the operator should 

 use some caution, as an inhalation of the dust creates much irritation of the 

 air passages. The general mode of administration is in decoction, but as the 

 active principle is volatile, a maceration with heat in close vessels would be 

 a more effectual mode of preparation. 



Dirca. — Linn. 



Calyx simple, coloured, corolliform, limb obsoletely 8-toothed. Corolla none. Stamens 

 8, unequal, exserted. Style filiform, lateral. Berry one-seeded. 



36 



