OX THE VOLATILITY AXD SOLUBILITY OF CAXTII ARID IX. 297 
partially decomposed and condensed in drops which subsequently 
solidified. This substance is soluble in alcohol, ether and chloro- 
form, is decomposed and dissolved by sulphuric acid, produces 
?io signs of vesication after forty-eight hours' contact with the 
skin under adhesive plaster, and is most probably the same vola- 
tile principle that has been noticed by Orfila. 
The long glass tube was then examined for a sublimate, by 
rinsing it thoroughly with chloroform, which, on evaporation, 
afforded more of the same substance obtained from the distilled 
water, and like it did not produce vesication. 
This experiment shows conclusively that cantharidin does not 
volatilize to an appreciable extent with water evaporating from 
cantharides. 
b. More water was added to the residue in the flask, again 
boiled for fifteen minutes and thrown on a displacing filter, and 
water added to the solid residue, after the decoction had ceased to 
pass, until the absorbed liquid was displaced. The decoction was 
much less odorous than the distilled water, and had a deep reddish- 
brown color. Half of this was agitated repeatedly with chloro- 
form. The latter decanted and evaporated yielded a crop of crys- 
tals intermixed with some coloring matter. A part of these heated 
in a tube over a lamp, gave immediately the brilliant crystalline 
sublimate of cantharidin well marked ; another portion applied to 
the skin produced vesication in a few hours. 
The other half of the decoction was evaporated to a soft extract 
by direct heat. This produced speedy and deep vesication, more 
effectual than that of pure cantharidin, as in the extract that 
principle was in a soluble state by virtue of the yellow matter of 
the flies. 
c. The residual flies were then dried carefully and exhausted 
with ether, which assumed a deep green color. A green semifluid 
fatty oil was obtained by evaporation, from which a fluid yellow oil 
separated by standing, which produced a tardy vesication, not 
comparable with the aqueous extract. 
d. One hundred grains of flies in powder were introduced 
into a test tube so as not to soil the sides. This was then kept 
at the temperature of 212° F. during six hours, by causing it to 
dip into a vessel of boiling water through a tin plate. The hy- 
grometric water was removed as it condensed above. At the 
26* 
