combinations of Oxymuriatic Gas and Oxygene , &c. 13 
colour of the potash instantly became white, and by a gentle 
heat, the whole was converted into muriate of potash : a cubical 
inch and ~ of oxymuriatic gas were absorbed, and exactly 
half a cubical inch of oxygene generated. The barometer 
during this operation was at 30.3, the thermometer at 62 
Fahrenheit. I made several experiments of the same kind, 
but this is the only one on which I can place entire depen- 
dence. When I attempted to use larger quantities of potas- 
sium, the retort usually broke during the cooling of the glass, 
and it was not possible to gain any accurate results in employ- 
ing metallic trays. The potassium was spread into a thin 
plate, and of course was much oxidated before its admission 
into the retort, which rendered the absorption of oxygene a 
little less than it ought to have been. In the process it was 
heated in vacuo before the combustion, to decompose the 
water in the crust of potash ; for in cases when this precaution 
was not taken, I found that hydrat of potash sublimed, and 
lined the upper part of the retort, and from this the oxy- 
muriatic gas separated water as well as oxygene. 
The phenomenon of the separation of water from hydrat of 
potash by oxymuriatic gas, was happily exemplified in an 
experiment in which I introduced oxymuriatic gas to the 
peroxide of potassium, formed in a large retort, and in which 
and nitrous oxide ; this is not the case : and he does not refer to experiment. I find 
by some very careful trials, that potassium attracts the oxygene and some of the nitro- 
gene from these bodies, and forms a fusible compound which may be decomposed, 
giving off nitrogene and its excess of oxygene, by a red heat, and which becomes 
potash, and not dry hydrat of potash. 
M. M. Gay Lussac and Thinard have convinced themselves that potassium 
and sodium are not hydrurets of potash and soda, by a method similar to that 
which I adopted and published some months before, namely, by producing neutral 
salts from them. 
