rhus. !.;:> 



of peas, which afterwards disappeared without opening them. 



After eight days the fore-arms were covered with squamous 



scales ; the itching lasted several days. These symptoms at 

 last disappeared after the application of ice. 



Horsfield {Exp. Diss, on the Effects of Rhus radicans, etc.) 

 gives the following as the effects of the leaves of this plant : 



" A slight degree of itching or sensation of heat, which gra- 

 dually increases, followed by redness or inflammation of the 

 skin ; in some very extensive ; in others, confined to round 

 circumscribed spots, or to longitudinal streaks. The inflamed 

 parts become elevated and tumefied ; small vesicles appear on 

 the surface, containing a pellucid fluid, which gradually in- 

 crease in size ; the fluid soon becomes yellow, and after some 

 time takes on the colour and consistence of pus. After the 

 vesications are completely distended, they break, and some of 

 the pus being discharged, by drying on the surface, forms a 

 yellow incrustation, which gradually becomes brown. The 

 itching and vesications which take place in the incipient 

 state frequently disappear and return several times succes- 

 sively. 



" The poison appears to have a peculiar capricious disposition 



to attack particular parts. In most cases the eyes are spe- 

 cifically affected; in some, the legs and thighs. A peculiar 

 and distressing itching of the scrotum and prseputium penis is 

 one of the most general and characteristic symptoms of the 

 disease. In quibusdam currit erectio penis, an fecminis labia 

 pudendee afFectantur. Its peculiar tendency to affect the eyes 

 is most strikingly observed in persons who by reading much 



become susceptible of the eruption ; in most of these, if its 

 progress is not stopped, blindness of a longer or shorter con- 

 tinuance is the certain consequence. 



" It has been observed that the eruption, when it is re-excited, 



Yaii-Mons and others assert that the active principle of this plant is a hydro- 

 carburetted gas, mixed with an acrid vapour, which acts most powerfully on 

 certain organ-. 



