combinations of Oxymuriatic Gas and Oxygene, &c. g 
and was oxidated.* The mercury in the barometer in these 
experiments stood at 30.12 inches, and that in the thermometer 
at 6 2 0 Fahrenheit. 
When these peroxides were formed upon muriate of potash, 
the colour of that from potassium was of a bright orange ; that 
from sodium of a darker orange tint. They gave off oxy- 
gene, as M. M. Gay Lussac andTHENARD state, by the action 
of water or acids. They were converted into alkali, as the 
French chemists have stated, by being heated with any metallic 
or inflammable matter. They thickened fixed oils, forming a 
compound that did not redden paper tinged with turmeric, 
without the addition of water. 
When potassium is brought in contact with fused nitre, 
in tubes of pure glass, there is a slight scintillation only, 
and the nitre becomes of a red brown colour. In this 
operation, nitrogene is produced, and the oxide of potassium 
formed. I thought that by ascertaining the quantity of nitro- 
gene evolved by the action of a given weight of potassium, 
and comparing this with the quantity of oxygene disengaged 
from the oxide by water, I might be able to determine its 
composition accurately. A grain of potassium acting in this 
way, I found produced only j~o °f nitrogene ; and the red 
oxide by its action upon water, produced less than half a 
cubical inch of oxygene, so that it is probable that potash as 
well as its peroxide is formed in the operation. 
* M. M. Gay Lussac andTHENARD have stated In the paper above referred to, 
that common potash and barytes absorb oxygene when heated. It would seem that 
the action of the fixed alkalies, and of barytes on platina, depends on the production 
of the peroxides. I have little doubt but that these ingenious gentlemen will have 
anticipated this observation, in the detailed account of their experiments. 
