412 Experiments on the Combinations of 
decompose nearly 4 cubical inches of muriatic gas... Mue, 
riate of soda ought on this idea to contain one proportion 
of sodium 22°, and one of oxymuriatic gas 32°9; and this 
estimation is very near that which may, be-gained from Dr. 
Marcet’s analysis of this substance. Hydrat of potash 
ought to consist of one proportion of potash, represented 
hy 48°, and one, of water, represented by 8°5. This gives 
its composition as 15°] of water, and 84°9 of potash. Hy- 
drat of soda ought, according to theory, to contain one 
proportion of soda 29°5, and one of water 8°5, which will 
give in 100 parts 22°4 of water; and the experiments that 
I have detailed, conform as well as can be expectcd with 
these conclusions. , 
The proportions of potash and soda, indicated, in different 
neutral combinations, by these estimations, will be found 
to agree very nearly = those deriyed from the most ac- 
curate analysis, particularly those of M. BerthoHet; or the 
differences are such as admit of an easy explanation, 
I stated in my last communication, the probability that 
the oxygen in the hyper-oxymuriate of potash was in triple 
combination with the metal and oxymuriatic gas; and new 
facts respecting the peroxide confirm this idea. Potassium, 
perfectly saturated with oxygen, would probably contain 
Six proportions; for, according to Mr. Chenevix’s analysis, 
which is confirmed by-one made im_ the laboratory of the 
Royal Institution, by Mr. E. Davy, hyper-oxymuriate of 
potash must consist of 40°5 potassium, 32°9 oxymurialic 
gas, and 45 of oxygen, salandenie tall . . 
I have mentioned, that by strongly heating the peroxide 
of potassium in oxymuriatic, acid, all the oxygen is expelled, 
and a mere combination of oxymuriatic gas and potassium 
formed. | thought it possible, that ata low temperature, a 
combination might be effected, and_I have reason to believe 
that this is the case. Imade a peroxide, of potassium, by 
heating potassiym with about twice the quantity of nitre, 
and admitted oxymuniatic gas which was absorbed: some 
oxygen was expelled on the fusion. of the peroxide, but a 
salt remained, which gave oxymuriatic eas, as well as mu- 
riatic acid, by the action of sulphuric acid. 
It seems evident, that in the formation of the hyperoxy- 
muriate of potash, one quantity of potash is decomposed by 
the attraction of oxymuriatic gas to form muriate of potash ; 
but the oxygen, instead of being set free in the nascent state, 
enters into combination with another portion of potash, to 
form a peroxide, and with oxymuriatic gas. 
‘The proportians required for these changes may be easily 
“t deduced 
