84 



MEDICAL BOTANY. 



Fig. 50. 



any higher degree than many of the 

 others. It is probahle that it is not a 

 native of. the United States, but like se- 

 veral others of the genus, has been 

 introduced from Europe. It is now, 

 however, extremely abundant in mea- 

 dows and other damp spots. This plant 

 and the R. bulbosus, the R. Jlammula, 

 and the R. sceleratus are so identical in 

 their properties, that they may be indis- 

 criminately employed. They are all per- 

 vaded by an acrid, volatile principle, which 

 is destroyed by the action of heat or even 

 by drying. It may, however, be collected 

 by distillation. Dr. Bigelow, in his experi- 

 ments, on several species of the genus, 

 found, that whilst the distilled product was 

 very acrid, the residuum was inert and 

 tasteless. This distilled water when first 

 tasted, excited no peculiar sensation, but in 

 a short time a sharp, burning effect was 

 produced ; when swallowed, it caused a 

 great sense of heat in the stomach. It 

 may be kept in closely-stopped bottles for 

 a length of time, without losing these pro- 

 perties. Tilebein states that the distilled 

 water of the R. sceleratus is excessively 

 acrid, and on cooling, deposits crystals, 

 which are almost insoluble in any men- 

 struum. Precipitates are caused by mu- 

 riate of tin and acetate of lead. 



Medical Uses. — From the caustic or 

 acrid character of these plants, they 

 were used as vesicatories, before the introduction of cantharides, and are 

 still employed for the same purpose, where the Spanish-fly is not to be had, 

 or where its use is contra-indicated. In most persons, they act promptly, 

 when applied to the skin, exciting redness and even vesication in half an hour, 

 but in consequence of their acting differently on different individuals, they 

 should always be used with much caution. In some persons scarcely any 

 effect is produced, whilst in others, on the contrary, their action is like that 

 of a poison, causing deep and extensive ulcerations, which are very difficult 

 to heal. At the same time, from their prompt powers, they have been found 

 of much benefit as counter-irritants in rheumatism, neuralgia, &c, or 

 wherever a powerful impression is wished to be made on the surface. 



R. acris. 



Tribe 3. Hellebores. — Calyx petaloid, with an imbricate aestivation. 

 Petals irregular, sometimes wanting. Carpels follicular, many-seeded. 



Helleborus. — Linn. 



Sepals, 5, persistent Petals 8 or many, bilabiate, tubular. Carpels many-seeded, coria- 

 ceous, nearly ereet. 



This genus of plants is principally European, and has long been celebrated 



