21 
combinations of Oxy muriatic Gas and Oxygene, &c. 
entirely volatilizes. I had similar results with muriate of 
strontia, and (though less distinct, more potassium distilling 
off unaltered) with muriate of baryta. Either the bases of 
the earths were wholly or partially deprived of oxymuriatic 
gas in these processes, or the potassium had entered into 
triple combination with the muriates. I hope on a future oc- 
casion to be able to decide this point. 
Combinations of muriatic acid gas with magnesia, alumine 
and silex, are all decomposed by heat, the acid being driven 
off, and the earth remaining free. I conjectured from this cir- 
cumstance, that oxymuriatic gas would not expel oxygene 
from these earths, and the suspicion was confirmed by experi- 
ments. I heated magnesia, alumine, and silex to redness in 
oxymuriatic gas, but no change took place. 
M. M. Gay Lussac and Thenard have shewn that baryta 
is capable of absorbing oxygene ; and it seems likely, (as ac- 
cording to Mr. Chenevix’s experiments, most of the earths 
are capable of becoming hyperoxymuriates) that peroxides of 
their bases must exist. 
I endeavoured to combine lime with more oxygene, by 
heating it in hyperoxymuriate of potash, but without success, 
at least after this process it gave off no oxygene in combining 
with water. The salt, called oxymurlate of lime, made for the 
use of the bleachers, I found gave off oxygene by heat, and 
formed muriate of lime. 
From the proportions wdiich I have given in the last 
Bakerian lecture, but which were calculated from the analyses 
of sulphates, it follows that if the muriates of baryta, 
strontia, and lime, be regarded as containing one proportion 
