IODIDE OF IRON BY DOUBLE DECOMPOSITION. 
173 
Wine of Iodide of Iron. 
ffc. Sulphate of iron, 8 parts. 
Iodide of potassium, - 10.5 " 
White wine, - 320. " 
The two salts are pulverised, a few drops of wine added 
to the mixture to assist the reaction, triturate for a few mo- 
ments, add the rest of the wine, and filter. 
Thirty-two parts of this wine contain one of the ferrugi- 
nous iodide, besides a little sulphate of potassa. 
This wine should be kept in glass stopped vials, nearly 
filled, or in vials stopped with corks which have had their 
tannin saturated with proto-sulphate of iron, and washed. 
The formula of Dr. Pierquin requires Bordeaux wine for 
the menstruum, but the tannin which exists in it in consi- 
derable proportion acts on the ferruginous salt, and I think 
it is preferable to substitute the white wine. 
All the preparations having a base of iodide of iron ob- 
tained by double decomposition being very easily and quick- 
ly made, it is not necessary to prepare them in advance, 
but every time they are demanded on prescription. 
Note. — The above method of M. Callond, (extracted 
from his memoir in the Journal de Pharmacie et de Chi- 
mie,) for obtaining iodide of iron by double decomposition 
is particularly advantageous for its prescription in pills. The 
commercial iodide of iron almost always contains free iodine, 
and sometimes in such excess that its administration in pills 
would be highly irritating to the stomach, and altogether 
improper, and this is the case with iodide prepared very 
carefully, unless kept absolutely hermetically sealed. The 
sulphate of potassa is almost inert in the quantity resulting 
and may be looked upon as a means of giving consistence 
to the pills. 
A syrup of iodide of iron may be made extemporaneous- 
ly, perfectly free from free iodine, and containing the offici 
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