36 
HYDRATED PEROXIDE OF IRON. 
the solution is easily found. As made by the first formula, 
provided the resulting solution measures two pints, each fluid 
ounce contains one hundred and fourteen grains of hydrated 
peroxide. 
This solution should be kept in every shop as a source for 
obtaining the peroxide for antidotal purposes, or for any of 
the preparations of that oxide called for in the course of busi- 
ness. 
Having this solution at hand ? supposing a sudden demand 
for the antidote occurs, the pharmaceutist should form a 
judgment as to the quantity of oxide wanted, and take a cor- 
responding amount of the ferruginous solution, mix it with its 
weight of water, and add a very slight excess of solution of 
ammonia to precipitate the oxide. 
The whole should be thrown on a coarse flannel, and by 
gradual pressure as much as possible of the fluid be removed. 
By again adding water, and compressing, the oxide is ob- 
tained sufficiently washed for the first exhibition, so that no 
time be lost, and the remainder should be treated more com- 
pletely, yet as rapidly as possible, so as to continue its admi- 
nistration at short intervals. By this course, the first doses 
may be administered in 10 or 15 minutes, if the manipulator 
has exercised ordinary skill. 
It is, of course, to be understood that the peroxide should 
be kept constantly on hand by every apothecary. After hav- 
ing washed it he should introduce it into bottles, in the form 
of a thick magma, so that after standing even for several 
months there should be little separation of water. This, how- 
ever long kept, or even the dry hydrated peroxide (the pre- 
cipitated carbonate of the U. S. P.) should be at once admi- 
nistered while the reeent is making, and thus save time, but 
the importance of having the recently prepared oxide, parti- 
cularly where the amount of poison taken is large, cannot be 
doubted. 
In the case of the Gigon family, in which nine persons were 
poisoned by arsenic, reported by Drs. Smiley and Wallace in 
the Medical Examiner, the writer had an opportunity of put- 
