6 
ORIGINAL COMMUNICATIONS. 
agitation serves to distribute it promptly through the super- 
natant fluid, which thus forms a medium for its administration, 
as well as a means for apportioning the dose. This mode is 
that which has been employed in the preservation of all the 
hydrated peroxide which I have ever made. Theoretical 
considerations induced me to employ it, counter to the dictum 
against which I now write; and experience, in the case already 
quoted, so fully satisfied me of the advantages to be derived 
from it, that I at once commenced the preparation of a large 
supply of the antidote, so that any future case might not be 
deprived of the benefit which can be obtained from its imme- 
diate use. Some of the oxide, prepared in June, 1838, is now 
by me, and to all appearance is entirely unchanged. No 
critical examination could distinguish it from a preparation a 
week old. Several friends, who have seen it, concur in this 
opinion. 
It was my intention to have here rested the argument, 
but just as it was completed, I was indebted to the kind- 
ness of Mr. Durand, who, ever anxious for the diffusion of 
information, and the improvement of our science, placed in 
my hands the twenty-fourth volume of the "Journal de Phar- 
macie," Paris, 1838, containing a communication from Drs. 
Bunsen and Berthold, " On the mode of preparing in the 
most convenient form the Hydrated Sesquioxide of Iron, as 
an Antidote to Jirsenious Acid." To these gentlemen we 
owe this employment of the hydrated oxide, and I therefore, 
with the greater pleasure, adduce their testimony in favor of 
the views which have been herein urged. 
As the subject now under discussion is in regard to the 
preservation of the oxide, the latter portion of their paper is 
first quoted, in their own words: " It is altogether inconceiv- 
able," say they, " that any one, relying upon uncertain expe- 
riments with animals, should have recommended the preser- 
vation and use of the antidote in a dry state, since a number 
of experiments already made, coinciding with our own, tend 
to this result, that the action of the sesquioxide of iron is 
null, and that of the dry hydrate incomplete; of which, the 
