THE BLEACHING COMPOUNDS .OF-CHLORINE. 299. 
more dilute. I am ignorant of'the state in which this chlorine exists : 
perhaps it forms alittle of the chloroxalic acid, which M. Dumas obtained 
by exposing acetic acid and chlorine to the influence of the solar rays ; 
perhaps also it existed in the’state of hydrochlorie acid, a state to which 
it might be reduced by the decomposition of water, the oxygen of which 
would contribute to the formation of the carbonic acid. 
- Inexact as this method of analysis is; it renders it very probable that 
chlorous acid is formed of two volumes of chlorine and one volume of 
oxygen. But the manner of its action with hydrochloric acid leaves 
no doubt on this subject. HIG 
Chlorous acid and hydrochloric acid produce, by their double decom- 
position, water atid chlorine, as already mentioned. Then if an excess 
of chlorous acid be made to act upon a given quantity of hydrochloric 
acid, the relation between the volumes of the acid gas decomposed and 
of the chlorine obtained, will allow the composition of the chlorous acid 
to be inferred from that of the hydrochloric acid. 
' Tattempted to effect this decomposition, both by passing hydrochloric 
acid gas over mercury into a graduated tube containing in its upper 
part a little’ very concentrated chlorous acid, and by introducing 
chlorous acid into a tube already containing hydrochloric acid gas. 
But the decomposition was in both cases produced in a very imperfect 
manner. The chlorine gas which is disengaged at first renders the so- 
lution of the hydrochloric acid gas difficult. In order that it may be 
complete, recourse must be had to agitation, which cannot be effected 
without a portion of the chlorine being absorbed by the mercury. 
The following mode’of operating, howevér, succeeded perfectly : 
after having filled a stopped bottle with hydrochloric acid gas in the 
mercurial ‘apparatus, I introduced a small phial of glass filled with 
chlorous acid and hermetically sealed’; I stopped the bottle, and I 
shook it so as to break the small phial. As soon as the chlorous and 
hydrochloric acid came into contact, decomposition took place with 
disengagenient of heat, and the interior of the bottle assumed a yellow 
tint. When this had returned to the temperature of the atmosphere I 
was able to open the phial over the mercury without a drop of this liquid 
metal entering or a bubble of gas escaping. The gas which thus filled 
it was entirely absorbed by mercury. 
In its decomposition by chlorous acid, the hydrochloric acid had 
been converted into an equal volume of chlorine. Then in this vo- 
lume of hydrochloric acid there was half a volume of hydrogen: the 
chlorous acid which had converted this hydrogen into water had 
yielded a quarter of a Volume of oxygen. On the other hand, the hy- 
drochloric acid decomposed could give only half a volume of chlorine ; 
and, as a whole volume had been produced, the other half volume must 
