Decomposition Flame of Methyl Nitrite

WHEN a stream of methyl nitrite vapour issuing from the mouth of an upright cylindrical glass tube about 5 cm. in diameter is ignited it burns in the air as a lambent diffusion flame, greyish-yellow in hue. At the inner surface of the diffusion flame an orange-red zone forms as a cone at the mouth of the tube. If the rate of flow is reduced, this orange-red inner flame peels away from the diffusion flame and slowly descends the tube as a flat disk surmounted by a fainter, conical afterglow of the same colour, easily visible in a darkened room. No oxygen is necessary for its propagation. After it has entered the tube it is not affected if the diffusion flame at the mouth is extinguished. It is the decomposition flame of pure methyl nitrite.