14,6 Mr. J. Davy on a gaseous Compound 
obtained, these two gasses were in such proportions, that the 
volume of the latter was double that of the former. 
I have ascertained by repeated trials, both synthetical and 
analytical, that the gas condenses four times its volume of the 
volatile alkali, and I have not been able to combine it with a 
smaller proportion. 
Tin fused in the gas in a bent glass tube over mercury, by 
means of a spirit lamp, rapidly decomposed it ; the liquor of 
Libavius was formed ; and when the vessel had cooled, there 
was not the least change of the volume of the gas perceptible; 
but the gas had entirely lost its offensive odour, and was 
merely carbonic oxide; for like carbonic oxide it burnt with a 
blue flame, afforded carbonic acid by its combustion, and was 
not absorbable by water. 
The effects of zinc, antimony, and arsenic heated in the gas, 
were similar to those of tin ; compounds of these metals and 
chlorine were formed, and carbonic oxide in each experiment 
was liberated equal in volume to the gas decomposed. In each 
instance the action of the metal was quick ; the decomposition 
being completed in less than ten minutes ; but though the 
action was rapid, it was likewise tranquil, no explosion ever 
took place, and none of the metals became ignited or in- 
flamed. 
The action even of potassium heated in the gas was not 
violent. But from the great absorption of gas, and from the 
precipitation of carbon indicated by the blackness produced, 
not only the new gas, but likewise the carbonic oxide, ap- 
peared to be decomposed. 
The white oxide of zinc heated in the gas quickly decom- 
posed it, just as readily indeed as the metal itself; there was 
