ON PERCHLORIDE OF IRON. 
171 
vapor may be all condensed by means of a proper refrige- 
rator, as it is essential to the success of the process that no 
steam should circulate around the capsule, for if the liquor 
be evaporated in air charged with moisture, it undergoes 
decomposition at a certain point of concentration, hydro- 
chloric acid being disengaged, and sesquioxide of iron pre- 
cipitated. It should be stirred with a glass spatula during 
the whole time of evaporation, which must be continued 
until the liquid no longer disengages any sensible vapors 
of hydrochloric acid, and a drop solidifies on cooling. When 
it has arrived at this point, the chloride is poured into per- 
fectly dry bottles furnished with good corks ; but as the salt 
on cooling becomes very hard, it is difficult to get it out 
of the bottles, to obviate which inconvenience, M. Sou- 
beiran, who repeated the process, very judiciously recom- 
mended to pour it into a plate which has been slightly 
greased, and immediately to cover it with another plate, 
and lute the two together. After about twenty-four hours, 
the plates are to be separated, the chloride broken, and im- 
mediately introduced into well-stoppered bottles. 
The perchloride of iron thus prepared possesses a dark 
yellowish-red color, no smell, and a very styptic taste. It 
is very soluble in water; the solution, which is of a fine 
golden-yellow color, keeps for an indefinite time exposed 
to the air without becoming turbid. It is also very soluble 
in alcohol and in ether. 
Exposed to the air, it rapidly absorbs moisture, which it 
at first solidifies, but it soon afterwards deliquesces, so that 
it is necessary to keep it in dry well-stoppered bottles. 
This chloride possesses the great advantage of keeping a 
long time without undergoing decomposition, owing, no 
doubt, to the small quantity of water which it contains. 
Thus the specimen which I possess is now, eight months 
after its preparation, in the same state as when first pre- 
pared. 
To determine the quantity of water which it contains, I 
