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SELECTED ARTICLES. 
as the pretended protoxide of chlorine of some chemists, is a 
very dissimilar compound, as Balard has proved beyond all 
doubt. As to the protoxide of chlorine discovered by Davy, 
it is no more than a mixture of chlorine and chlorous acid; 
which is proved by the action of water and protochloride of 
mercury on it, these agents separating the two mixed gases; 
and also by the unusual contraction of one sixth of the volume 
of its component gases, which this compound would offer. 
The following formula will express the reaction by which the 
gas is produced: 
2KO, Ch 2 5 4-12HCh=2KCh 2 + 6H 3 + 6Ch 3 0=2KCh 2 
-f 6lPO + 3Ch0 2 + 9Ch. 
Thus the pretended protoxide of chlorine, resulting from 
the reaction of chlorohydric acid on chlorate of potassa, may 
be considered nothing more than a uniform mixture of one 
volume of chlorous acid gas ChO 3 and three volumes of chlo- 
rine. This supposition accounts not only for the constancy 
of the composition of the protoxide, (which has led many to 
consider it a definite compound,) but also for the contraction 
of one sixth of the total volume of its constituent gases, for in 
a volume of chlorous acid gas, there is a contraction of one 
third of the volumes of its component gases; therefore in an 
invariable mixture of a volume of this gas with three volumes 
of chlorine,there should be a contraction of one sixth of the 
total volume. This contraction confirms what the experiments 
of Soubeiran had already proved, that Davy's protoxide of 
chlorine was but a mixture of chlorine and chlorous acid gas. 
The second oxygenized compound of chlorine, that which is 
procured by the action of sulphuric acid on chlorate of potassa, 
by the process of Count Stadion, is also evidently an acid; 
1st, because it neutralizes completely the soluble alkaline ox- 
ides; and 2d, because, according to the electro-chemical theory, 
it is impossible that an oxide of chlorine, more highly oxy- 
genized than hypochlorous acid, can possess the properties of 
an acid in an inferior degree to it. We will therefore con- 
tinue to call this gas chlorous acid, and its salts with basic ox- 
ides, chlorites. 
