294 
ON IODIDE OP POTASSIUM. 
we evaporate to dryness, and purify the residuum with al- 
cohol, or reserve it for this purpose till a sufficient quantity 
is collected. 
We obtain the iodide of potassium in beautifully regular 
crystals, by covering the bason, after due concentration, 
with a plate, which prevents rapid evaporation from the 
surface, and the consequent formation of a crust, placing it 
on a bad conductor, such as a piece of charred wood, and 
surrounding the whole with several folds of a dry cloth, 
formed of some good non-conducting substance ; in this 
way the liquid cools very slowly, and allows time for 
the solid particles to arrange themselves in a regular 
manner. 
A saturated alcoholic solution of the iodide, which had 
been used for its purification, after standing aside for about 
twelve months in a bottle loosely corked, had deposited, at 
the bottom of the bottle, a mass of loose acicular silky 
crystals. 
It is almost invariably asserted in chemical works, that 
the iodide is a deliquescent salt; this is not the case when 
it is perfectly pure and free from excess of the very deli- 
quescent carbonate of potash. We have kept a pure spe- 
cimen crystallized from alcohol in an open dish, exposed to 
all conditions of the atmosphere for weeks, without appear- 
ing damper than when just taken from the stove. 
Pharmaceutical Journal. 
