combinations of Oxy muriatic Gas and Oxygene, &c. 29 
employed, the whole of the oxgene is expelled, and the same 
compound formed. It is contrary to sound logic to say, that 
this exact quantity of oxygene is given off from a body not 
known to be compound, when we are certain of its existence 
in another ; and all the cases are parallel. 
An argument in favour of the existence of oxygene in oxy- 
muriatic gas, may be derived by some persons from the cir- 
cumstances of its formation, by the action of muriatic acid on 
peroxides, or on hyperoxymuriate of potash ; but a minute in- 
vestigation of the subject will, I doubt not, shew that the 
phaenomena of this action are entirely consistent with the 
views I have brought forward. By heating muriatic acid gas 
in contact with dry peroxide of manganese, water I found 
was rapidly formed, and oxymuriatic gas produced, and the 
peroxide rendered brown. Now as muriatic acid gas is known 
to consist of oxymuriatic gas and hydrogene, there is no 
simple explanation of the result, except by saying that the 
hydrogene of the muriatic acid, combined with oxygene 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 supplying 
oxygene. I 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 oxygene. 
I filled a glass globe 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 
