THE BLEACHING COMPOUNDS OF CHLORINE. 307 
the chlorous acid escaped decomposition and. .was disengaged in the 
form of vapour. 
The phznomena are rather different when oxide of copper or of zinc 
is employed ; the solutions of the sulphates of these metals are decom- 
posed by hypochlorite of lime, and sulphate of lime and the metallic 
oxide are precipitated together. If the: chlorite of lime is in excess, the 
liquor does not retain the slightest portion of either metal, and by dis- 
tillation hypochlorous acid only is obtained. 
When however the hydrates of zine and copper are treated with 
chlorous acid, a certain quantity of them is dissolved, and the liquid 
possesses decolorizing properties. Since, then, perfectly free chlorous 
acid dissolves these ipettics and these compounds are precipitated by 
solutions of alkaline chlorites, which contain an excess of chlorous acid, 
it is natural to suppose that in these cases this chlorous acid is not ina 
perfectly free state. It is therefore probable that some alkaline oxides, 
lime for example, are susceptible of forming bihypochlorites, which 
are decomposed by evaporation in vacuo into neutral hypochlorites and 
hypochlorous acid. 
The hypochlorites of zine and copper, the existence of which is ren- 
dered probable by what I have stated, suffer decomposition very readily. 
When they are distilled they evolve hypochlorous acid, and probably a 
little oxygen, and they are converted into oxichlorides. The oxichloride 
of copper is of a fine green colour ; that of zinc is white, with an agree- 
able pearly lustre ; it:decomposes spontaneously into chloride and chlo- 
rate; with the disengagement of oxygem and a little chlorine. As to 
that.of copper, it is decomposed:/by:an excess’ of oxide, which it con- 
verts: into. insoluble A a also disengaging a mixture = oxygen 
-and chlorine. ok OLS BD 
These chlorites, riitoeil saith eile maybe pbiginal as vcattbatiea 
ind M. Grouvelle, by agitating either of these oxides, diffused through 
water, with chlorine. The:absorption of the gas is rapid, especially by 
-the oxide of zinc ; the distilled liquor precipitates an oxichloride, as ob- 
served by M. Grouvelle, and it contains a metallic chloride in’ solution. 
A portion of dilute hypochlorous acid is condensed. : In the absence of 
peroxide of mercury; the oxide of zinc and that of copper may serve for 
‘the preparation of this acid. The hypochlorites of powerful-bases pos- 
sess the following properties: their odour and colour are identically the 
same as the corresponding decolorizing compounds of chlorine, from 
which it is impossible to distinguish them: by their physical properties; 
they are salts of a very changeable constitution. A slight increase of 
_-temperature, the influence of solar light, even of diffused light,:converts 
them into chlorides and chlorates. I have not estimated the relation 
between the atomic quantities of these two salts. 
-. This change is effected in the greatest numberof cases with the dis- 
