The first method adopted was inflammation by means of oxygenated muriate of potash. A small particle of oxygenated muriate of potash was inserted into the phosphorus to be burnt. On the application of a wire, moderately hot, to the point of insertion, the salt was decomposed by the phosphorus, and sufficient fire generated and partially applied by the slight explosion, to produce the combustion of the phosphorus, without the previous sublimation of any part of it. The second way employed was the ignition of a part of the phosphorus, by means of the combustion of a small portion of tinder of cotton,[173] or paper, in contact with it, by the burning glass. [173] It will be seen hereafter that these bodies are easily inflamed in nitrous oxide. The third, and most successful mode, was by introducing into the graduated jar containing the nitrous oxide, the phosphorus in a small tube containing oxygene, so balanced as to swim on the surface of the mercury, without communicating with the nitrous oxide. The phosphorus was fired in the oxygene with an ignited iron wire, by which at the moment of combustion, the tube containing it was raised into the nitrous oxide, and thus the inflammation continued. _d._ In different experiments, made with accuracy, I found that the whole of a quantity of nitrous oxide was never decomposable by ignited phosphorus; the combustion always stopped when the nitrous oxide remaining was to the nitrogene evolved as about 1 to 5; likewise that the volume of nitrogene produced was rather less than that of the nitrous oxide decomposed, and that this deficiency arose from the formation of nitrous acid by the intense ignition produced during the process. Of one experiment I shall give a detail. Temperature being 48°, two cubic inches of pure nitrous oxide, which had been generated over mercury, were introduced into a jar of the capacity of 9 cubic inches, graduated to,1 cubic inches, and much enlarged at the base. A grain of phosphorus was inserted into a small vessel about one third of an inch long, and half an inch in diameter, containing about 15 grain measures of very pure oxygene; this vessel, which swam on the surface of the mercury, was carefully introduced into the jar containing the nitrous oxide. The phosphorus was fired by means of a heated wire, and before the oxygene was wholly consumed, the vessel containing it elevated into the nitrous oxide. The combustion was extremely vivid and rapid. After the atmospheric temperature was restored, the gas was rendered opaque by dense white vapor. When this had been precipitated, and the small vessel removed from the jar, the gas filled a space nearly equal to 1.9 cubic inches. On introducing to it a little solution of green muriate of iron, and prussiate of potash, green prussiate of iron was produced: hence, evidently, nitrous acid had been formed. On the admission of pure water, an absorption of rather more than,3 took place.