378 
As the acid principle was soluble in alcohol of about 50 per 
cent. haga 100 — ot the bark were exhausted by 
pressure, and the resulting turbid Fquid sapesbealy shaken out 
with petroleum spirit. The petroleum spirit solution, evaporated 
to dryness at a low temperature, left a small quantity of a pale 
yellowish viscous residue. This was dissolved in 15 c.c. of 
aleohol, the solution diluted with an equal volume of water, and 
the acrid principle again extracted with petroleum spirit and 
finally with ether. The mixed solutions, evaporated to dryness, 
left 0- 239 gramme of a brownish-yellow viscous oil, which rapidly 
darkened on heating to 100 deg. The quantity was too small 
to allow of dudes attempts at puri Eat vation. 
ing i 
nearly 24 hours. A tincture of the bark made with 50 per ee 
alcohol had a similar taste, and also produced, when applied to 
the skin, a persistent redness and irritation. 
The active princinle of the bark appears, therefore, to be an 
acrid viscous oil, or soft resin 
Acrid principles of this nature are, as is well known, widely 
spread in the genus Euphorbia, of the natural order Lu iphorbr- 
aceae, and are also found in croton oil and the milky juice of 
the manchineal. Most pe a of the genus Croton, however, 
contain, as far as is known, bitter principles (C. ‘Eleuteria, 
C. niveus) or alkaloids that have not yet heen sufficiently 
examined 
