combinations of Oxymuriatic Gas and Oxygene, &c, 25 
3.1, for tellurium 2.4, for mercury 1.05,* for zinc 3.2, for iron 
5.8, for tin 4, for bismuth 1.5, for copper 3.4, for lead .$), 
for silver, the absorption of volume was T 9 -, and the increase 
of weight of the silver was equivalent to fo °f a grain. + 
In acting upon metallic oxides by oxymuriatic gas, I found 
that those of lead, silver, tin, copper, antimony, bismuth, and 
tellurium, were decomposed in a heat below redness, but the 
oxides of the volatile metals, more readily than those of the 
fixed ones. The oxides of cobalt and nickel were scarcely 
acted upon at a dull red heat. The red oxide of iron was not 
affected at a strong red heat, whilst the black oxide was rapidly 
decomposed at a much lower temperature ; arsenical acid un- 
derwent no change at the greatest heat that could be given it 
in the glass retort, whilst the white oxide readily decomposed. 
In cases where oxygene was given off, it was found exactly 
the same in quantity as that which had been absorbed by the 
metal. Thus 2 grains of red oxide of mercury absorbed 
of a cubical inch of oxymuriatic gas, nd afforded 0.45 of oxy- 
gene. J Two grains of dark olive oxide from calomel decora- 
* The gas in these experiments was not freed from aqueous vapour, and as stopcocks 
of brass were used, a little gas might have been absorbed by the surface of this metal, so 
that the processes offer only approximations to the composition of the oxymuriates. The 
processes on lead, tellurium, iron, antimony, copper, tin, mercury, and arse ;ic, were 
carried on in three successive days, during which the height of the mercury in the 
barometer varied from 30.26 inches to 30.15, and the height of that in the thermo- 
meter from 63.5 to 61 Fahrenheit. 
The experiment on silver was made at the temperature of 52 Fahrenhjit, and 
under a pressure equal to that of 29.9 inches. 
f This agrees nearly with another experiment made by my brother, Mr. John 
Davy, in which 12 grains of silver increased to 15.9 during their conversion into 
horn- silver. 
X I have made two analyses of corrosive sublimate and calomel, with considerable 
MDCCCXI. E 
