420 Experiments on the Combinations of 
An argument in favour of the existence of oxygen in 
oxymuriatic gas, may be derived by some persons from the 
circumstances of its formation, by the action of muriatic 
acid on peroxides, or on hypcr-oxymuriate of potash; but 
a minute investigation of the subject will, I doubt not, show 
that the phenomena of this action are entirely consistent 
with the views T have brought forward. By heating mu- 
riatic acid gas in contact with cry peroxide of manganese, 
water I found was rapidly formed, and oxymuriatic gas 
produced, and the peroxide rendered brown. Now as mu- 
matic acid gas is known to consist of oxymuriatic gas and 
hydrogen, there is no simple explanation of the result, ex- 
cept by saying that the hydrogeti of the muriatic acid com- 
bined with oxygen from the peroxide to produce water. 
Scheele explained the bleaching powers of the oxymuriatic 
gas, by supposing that it destroyed colours by combining 
with phlogiston. Berthollet considered it as acting by sup- 
plying oxygen. _T have made an experiment, which seems 
to prove that the pure gas is incapable of altering vegetable 
colours, and that its operation in bleaching depends entirely 
upon its property of decomposing water, and liberating its 
oxygen. 
I filled a glass elobe containing dry powdered muriate of 
lime, with oxymuriatic gas, I introduced some dry paper 
tinged with litmus that had been just heated, into another 
globe containing dry muriate of lime; after some time this 
globe was exhausted, and then connected with the globe 
containing the oxymuriatic gas, and by an appropriate set 
of stop-cocks the paper was exposed to the action of the 
gas. No change of colour took place, and after two days 
there was scarcely a perceptible alteration. 
Some similar paper dried, introduced into gas that had 
not been exposed to muriate of lime, was instantly rendered 
white *, fe 
Paper that had not been previously dried, brought in con- 
tact with dried gas, underwent the same change, but more 
slowly. ight ; 
The hyper-oxymuriates scem to owe’ their bleaching 
powers entirely to their loosely combined oxygen; there is 
a strong tendency in the metal of those in common usc, to 
form simple combinations with oxymuriatic gas, and the 
oxygen Is easily expelled or attracted from them. 
* The last experiments were made in the laboratory of the Dublin Society;” 
most of the preceding ones in the laboratory of the Royal Institution 5 and 
I have been permitted to refer to them. by the managers of that useful public 
establishment, 
It 
