306: BALARD'S RESEARCHES CONCERNING THE NATURE OF 
rates ; and, on theother hand, I havé already stated,‘ that the metallic 
chlorides are decomposed by chlorous acid, and yield, among other pro- 
ducts, chlorine gas: The forniation of a chlorate is therefore always 
accompanied with a corresponding production of chloride. 
The hypochlorites of barytes and lime serve for the preparation of 
other hypochlorites, by double decomposition. 
Potash, soda, lithia, strontia, barytes, lime and magnesia are bases 
which, by combining with hypochlorous acid, form salts with it, the ex- 
istence of which is incontestible. I could not however forget that 
M. Grouvelle, while examining the decolorizing combinations of chlo- 
rine, observed that peroxide of iron, oxide of copper and of zinc, ab- 
sorbed this gas very rapidly, and formed with them decolorizing com- 
pounds, which heat and exsiccation converted into chlorine and oxides: 
I therefore endeavoured to produce the hypochlorites of these metals, 
either by directly combining hypochlorous acid with their oxides, or by 
double decomposition between the sulphates of these bases and the hy- 
pochlorite of lime and barytes. 
In experimenting with iron, I did not obtain indications of combination 
by either of these methods. On the one hand hypochlorous acid, made to 
act upon peroxide of iron, did not dissolve the slightest portion of it ; ‘and 
on the other, by the decomposition of hypochlorite of lime by persul- 
phate of iron, I obtained sulphate of lime and peroxide together ; and 
the liquor, which contained free hypochlorous acid, contained no iron. 
This proves two things ; first, that hypochlorous acid is extremely weak, 
since the base with which it was combined acts with persulphate of iron 
as if it were uncombined ; and secondly, that hypochlorite of peroxide 
of iron cannot exist. 
The results which I have obtained thus differ from those observed 
by M. Grouvelle; and I endeavoured to discover the cause of this dis- 
agreement. When operating as he did, that is to say by subjecting 
hydrate of iron to the action of chlorine, I found that the gas was 
slowly absorbed, and that the liquor was, as he stated, strongly decoloriz- 
ing, even after boiling for a quarter of an hour ; but I also convinced 
myself that during the Sapte not only chlorine, but chlorous acid, 
was liberated. 
The liquid, before muillition, contained a persalt of iron; but during 
distillationalmost the whole of the peroxide was deposited in a pure state.’ 
It appears, then, that in the action of peroxide of iron upon chlorine, 
both perchloride of iron and chlorous acid were formed, compounds 
which might co-exist, on account of the diluted condition of both of them. 
The intervention of heat had the effect of destroying that which had 
been produced in the cold, and of producing an inverse re-action, from 
which there resulted peroxide of iron and chlorine, while a portion of 
engagement of oxygen. Nevertheless, with the addition of certain cir- 
ih 
