THE VOLATILITY AND SOLUBILITY OF CANTIIARIDIN. 47 
peculiarly liable to enter into putrefaction. Sulphurous acid 
can be easily prepared by burning sulphur, or by heating oil 
of vitriol, along with charcoal, or vegetable matter. Its cor- 
rosive action is very slight; its disinfecting action very 
powerful. The sulphite of soda is now prepared in quantity 
at different chemical works. The addition of a stronger acid 
sets free the sulphurous from its salts. As to its mode of 
action, if we concur with Liebig in believing that morbific 
matters resemble ferments, in being active only whilst under- 
going a decomposition which is mainly determined by the 
oxygen of the air, we may suppose sulphurous acid to render 
the poisonous matter inert, by preventing its oxidation. 
This acid, moreover, is a powerful deoxidising agent, and it 
may be by removing oxygen from organic poisons that it 
renders them inert, by decomposing them. 
cc Further, sulphurous acid can combine with certain ele- 
ments of organic bodies, as we see in its temporary bleach- 
ing action on vegetable colours ; and it may be thus that it 
neutralises morbific matters. In one or other, or all of those 
modes, this agent may act as a disinfectant; but, at all 
events, its action is very powerful, and it deserves much more 
attention than it has received. 
“ The only other substance to which I shall at present refer. 
Is pitch oil, one of the products of the distillation of tar. It 
s an antiseptic of the most powerful class, and very cheap, 
ind if not used in excess it is applicable as a deodoriser ; but 
its own strong tarry smell interferes with its extensive use.” 
— Pharmaceutical Journal, December , 1852. 
)BSERVATIONS ON THE VOLATILITY AND SOLUBILITY 
OF CANTHABIDIN. 
By William Procter, Jun. 
“ Cantharides have been used in Pharmacy since the 
days of Hippocrates. It was not till 1810, however, that the 
principle giving them activity was isolated by Robiquet 
(Anal, de Chimie , lxxvi, 302,) and subsequently named Cantha - 
ridin by Dr. Thomas Thompson. Since then various 
experimenters have been engaged in the chemical investiga- 
tion of these flies, and in the more recent treatises they are 
stated to consist of cantharidin , yellow fixed oil , green fixed oil , 
a yellow viscous substance , a black matter , ozmazone , uric acid , 
