ON RESIN OP GUAIACUM. 
67 
as to obtain a very adhesive croton oil plaster, which causes 
a powerful irritation of the skin. 
M. Caventou, in a note in reply to M. Bouchardat's Me- 
moir, wished to establish his right to the propagation of 
croton oil as a therapeutical agent. He thinks that the heat 
to which the oil is submitted at the time of mixing must in- 
jure its properties, which would be true if M. Bouchardat 
did not add the croton oil to the liquefied and partially 
cooled plaster. M. Caventou prefers the following for- 
mula: — 
P. Hog's lard 2\ parts 
Wax 5 part. 
Croton oil 1 part. 
The wax and lard are melted together, and the croton oil 
is incorporated when they are cold. 
Ibid, from Bulletin de Therapeutique. 
ART. XVII. — ON RESIN OF GUAIACUM. 
By M. Deville. 
Resin of guaiacum gave, by distillation, three distinct 
substances: — 
1. An oil boiling at 117° C. 
2. An oil boiling at 212° C, more dense than water, 
while the other is lighter. 
3. A crystallised substance, volatile without decomposi- 
tion. 
This work, whose results would appear, at first sight, to 
have great analogy with those which I have published con- 
