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PROOFS OF THE PROPERTIES OF OXIGEN GAS.

Rationale. ..Sulphur is a simple combustible body, whichpossesses the property of decomposing oxigen gas at a high tem-perature, by attracting the oxigen from the caloric with which itwas combined, in order to be converted into sulphuric acid.

Experiment III.

Combustion of charcoal in oxigen gas.

The oxigenation of charcoal may be effected like that of phos-phorus in the receiver placed over mercury. But as the heat ofthe red-hot iron is not sufficient to ignite the charcoal, a smallpiece of tinder with a minute particle of phosphorus are broughtin contact with it; these being set on fire will kindle the char-coal, which then will burn and throw out scintillating sparks inall directions.

After the combustion ceases, it will be found that the elasticfluid under the receiver has not disappeared, as was the casein the former experiments; but that a new peculiar kind of gasis formed. This air is unfit for respiration and incapable ofmaintaining combustion. It is greatly absorbed by cold water,and vanishes by lime-water, barytic-water, or by other alca-lies, which first are rendered turbid, and prove it to be anacid, consisting of charcoal and oxigen; hence it is called car-bonic acid gas. Whatever quantity of gas remains after the ab-sorption by alcalies, is that portion of oxigen gas, which hasescaped the action of the charcoal during the combustion.

Rationale. ..The charcoal in this case likewise effects a de-composition of the oxigen gas. When charcoal is ignited, its af-finity for oxigen is stronger than that of caloric, it thereforeunites to it and forms carbonic acid which assumes the gazeousstate at the temperature of our atmosphere. The light and heatbecome liberated and appear under the form of fire.