Mr. Davy’s Researches on the 
242 
and hydrogene at the negative surface, facts which are certainly 
unfavourable to the idea of the existence of hyperoxygenised 
muriatic acid, whether it be imagined a compound of oxy- 
muriatic acid with oxygens, or the basis of oxymuriatic acid. 
If the facts respecting the hyperoxymuriate of potash, 
indeed, be closely reasoned upon, it must be regarded as 
nothing more than as a triple compound of oxymuriatic acid, 
potassium, and oxygene. We have no right to assume the 
existence of any peculiar acid in it, or of a considerable por- 
tion of combined water ; and it is perhaps more conformable 
to the analogy of chemistry, to suppose the large quantity of 
oxygene combined with the potassium, which we know has an 
intense affinity for oxygene, and which from some experi- 
ments, I am inclined to believe, is capable of combining directly 
with more oxygene than exists in potash, than with the oxy- 
muriatic acid, which, as far as is known, has no affinity for 
that substance. 
It is generally supposed that a mixture of oxymuriatic acid 
and hyperoxymuriatic acid is disengaged when hyperoxy- 
muriate of potash is decomposed by common muriatic acid ;* 
but I am satisfied from several trials, that the gas procured in 
this way, when not mixed with oxygene, unites to the same 
quantity of hydrogene, -f as common oxymuriatic acid gas 
from manganese ; and I find, by a careful examination, that 
the gas disengaged during the solution of platina, in a mixture 
9 If hyperoxymuriate of potash be decomposed by nitric or sulphuric acid, it affords 
oxymuriatic acid and oxygene. If it be acted upon by muriatic acid, it affords a 
large quantity of oxymuriatic acid gas only. In this last case, the phenomenon seems 
merely to depend upon the decomposition of the muriatic acid gas, by the oxygene, 
loosely combined in the salt. 
f This likewise appears from Mr. Cruickshank’s experiments. See Nicholson’s 
Journal, Vol. V. 4-to. p. 206. 
