284 BALARD’S RESEARCHES CONCERNING THE 
It is probable that the disposition of oxide of copper to combine 
with the chloride of this metal to form an oxichloride, contributed to 
render copper, though less oxidizable than zinc or tin, proper to produce 
the decpmposition of chlorous acid,—an operation which these two last 
metals cannot effect. 
This is probably also the cause which renders the action of mercury 
so prompt. When a few globules of this metal are shaken with chlo- 
rous acid, it is almost instantaneously decomposed, without any appa- 
rent disengagement of gas of any kind, and oxichloride of mercury is 
found to be the product of this re-action. The disposition which the two 
products of this decomposition have to combine is undoubtedly the 
reason which renders it so easy of execution. 
The kind of alteration which silver causes chlorous acid to undergo, 
is precisely the reverse of that of the bodies whose action upon this 
acid has been hitherto described. When very finely divided silver is 
put into contact with chlorous acid, a brisk effervescence takes place, 
which is produced by a disengagement of oxygen gas, without any 
trace of chlorine, and the whole of this combines with the silver and 
converts it into chloride. 
To recapitulate:—The bodies which I have tried, chlorine and the 
metals of the last section of Thénard excepted, decompose chlorous 
acid; they are oxigenated at its expense, and set some chlorine at 
liberty, which can be only partially absorbed by the combustible, 
except in some peculiar circumstances. Silver alone is an exception to 
this law of disengaging oxygen : and this phenomenon, as well as the 
decomposition of fluoride of silver by chlorine, indicates the very 
peculiar affinity which exists between these two bodies. 
Chlorous acid is therefore one of the most energetic oxidizing 
agents. The property which it has of converting bromine into bromie 
acid, and selenium into selenic, and not selenious acid, gives it in this 
respect an incalculable advantage over nitric acid, and up to a certain 
point over oxigenated water. 
To judge of its effects as an oxidizing agent only by its action on the 
metals, it might perhaps be ranged below nitric acid; but it must be 
remembered, that the action of nitric acid on metallic substances does 
not depend on their oxidability alone, and the easy decomposition of 
the acid, but also on their disposition to form a nitrate, and a nitrate 
soluble in acid, of the degree of concentration employed. This is 
proved by the singular action which it exerts upon iron and tin in 
certain cases. ’ 
Chlorous acid not having much power to form salts, except with the 
oxides of those metals which yield energetic bases, it ought not to 
cause surprise that they excite so little definite action upon the others. 
This power of oxidizement possessed by chlorous acid is a perfectly 
