PHARMACEUTICAL OBSERVATIONS. 
5 
is modified from that mentioned by Pereira as having been 
proposed by the late Dr. Turner, and has yielded the best 
results in my hands ; it is as follows : — 
Saturate a hot, freshly prepared solution of potassa, with 
iodine added in small quantities at a time, and stirring well 
after each addition^ until the liquid shows a slight excess of 
iodine, by the reddish colour imparted — evaporate the solu- 
tion and mix the resulting salt with about an eighth of 
powdered charcoal, and subject it to a dull red heat in a 
common iron pot ; the iodide is next dissolved out of the 
residue, the solution filtered, and on evaporation yields a 
perfectly pure salt. 
The iodide prepared as above gave no trace of carbonate 
of potassa, chlorides, sulphates or iodates; the pure salt is 
deliquescent as it slowly liquifies when exposed to the air. 
Liq. Ferri Iodidi. 
In preparing the Liquor Ferri Iodidi, it is important to 
observe that none but the best American honey should be 
used, as the Cuba honey which is the kind generally met 
with in the shops, does not effectually protect the solution 
from change. 
Tinctures. 
Small quantities of vegetable tinctures may be prepared 
in a few minutes when wanted for prescriptions, by redu- 
cing the root or leaves to moderately fine powder, and 
boiling for a short time in the requisite quantity of alcohol ; 
the tincture should then be allowed to cool before filtering, 
in order that all substances not soluble in cold alcohol may 
be deposited. This process requires less time for its execu- 
tion than that of displacement. 
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