NATURE OF THE BLEACHING COMPOUNDS OF CHLORINE. 279 
fused in water, the chlorous acid, which would seem to be pte is 
nevertheless mixed with a large quantity of chloric acid. 
Indeed, when chlorine is agitated with oxide of silver, it is an ope- 
ration which, whatever be the rapidity with which it is conducted, 
requires a minute or two that the absorption of the chlorine may be 
complete ; even in this case a portion of the chlorite is decomposed, 
and converted, as usually happens, into chloride and chlorate, and the 
latter decomposed in its turn by the chlorine produces chloric acid. 
Thus, in whatever manner the operation is conducted, a notable por- 
tion of the chlorous acid is changed into this new compound. 
But this chlorous acid is fortunately possessed of a volatility which 
allows of its separation from the bodies with which it is mixed, and it 
may be obtained diluted with water by distilling the liquid prepared 
by employing one of these three methods. However, as a high tem- 
perature may decompose it in part, and as at the heat of boiling water 
some of the substances with which it is mixed, as hydrochloric and 
nitric acid, may come over in distillation, it is better to operate in 
vacuo, or at least under low pressure, at a temperature below 212° 
Fahrenheit. A solution of chlorous acid is thus obtained, but diluted 
with much water. The first product is the richest in chlorous acid; if 
this be kept apart and be again distilled, chlorous acid may be obtained 
in a concentrated state. 
These methods supply, it is true, but very small quantities, and I 
should have renounced the study of the properties of this new oxigen- 
ated compound of chlorine, if I had not discovered a more economical 
and productive process. This method consists in treating chlorine with 
red oxide of mercury suspended in water. 
The action of chlorine upon this compound has been already studied 
by M. Grouvelle. This chemist has stated that oxichloride of mer- 
-eury, very slightly soluble in cold water, was formed. M. Thénard, 
on the other hand, has observed that the liquid contained chloride and 
chlorate of mercury also in solution; but I am at liberty to suppose 
that these bodies are only formed consecutively, and that their exist- 
ence had been preceded by that of a mercurial chlorite, as takes place 
with the salts of silver. 
Certain theoretical considerations made me conceive some hope in 
employing oxide of mercury. In fact, if we reflect on the conditions 
which appear the most favourable for producing and isolating chlorous 
acid, it will be seen that they are reducible to the four following ; Ist, 
the action of chlorine on a strongly alkaline oxide; 2ndly, that this 
oxide should form a chlorite possessing a certain degree of stability ; 
$rdly, that the metallic chloride formed may, on account of its insolu- 
bility, easily separate from the chlorite ; 4thly, and lastly, that it 
should re-act but feebly on the chlorous acid when it is separated by 
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