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GAZEOUS OXID OF NITROGEN.

Charcoal, sulphur, iron, and the compound inflammable bo-dies decompose this gas, only at temperatures equal to, or abovethat of ignition, probably each at a different temperature.

The double flame produced during the combustion of charcoal,depends on the production of nitrous acid formed during the pro-cess ; for it may be produced by plunging the taper into commonair containing nitrous acid vapour or in a mixture of gazeous oxidof nitrogen and nitrogen gas, through which nitrous acid hasbeen diffused. It is never perceived in the combustion till muchnitrous acid is formed.

If a taper be suffered to burn in a mixture of equal parts ofgazeous oxid of nitrogen and nitrogen gas, it burns at first witha flame nearly the same as that of a candle in common air,whitish yellow. Before its extinction the interior white flameand exterior blue one are perceived.

tsitrous oxid is therefore a gas unalterable in its constitutionat temperatures below ignition. It is composed of oxigen andnitrogen, existing most probably in the most intimate unionwhich those substances are capable of assuming. For it is un-alterable by those bodies which are capable of attracting oxigenfrom nitrous gas, and nitrous acid at common temperatures.The properties of nitrous oxid approach to those of acids.