6. From lean flesh digested in nitric acid, at a gentle heat.
Prop., &c. Pure nitrogen is a colourless, odourless, tasteless gas, neither combustible nor capable of supporting combustion or respiration. It is neutral to test-paper, does not affect lime water, and is only slightly absorbed by pure water. Its sp. gr. is ·9713. It is recognised by its purely negative qualities.
Nitrogen, Chlo′′ride of. NCl3. Syn. Nitrogen trichloride, Terchloride of nitrogen. This compound was discovered by Dulong in 1811, but its nature was first accurately determined by Sir H. Davy.
Prep. (Liebig.) Dissolve chloride of ammonium, 1 oz., in hot water, 12 or 14 oz., and as soon as the temperature has fallen to 90° Fahr., invert a wide-mouthed glass bottle full of chlorine over it. The gas is gradually absorbed, the solution acquires a yellowish colour, and in the course of 15 to 20 minutes yellow, oil-like globules of chloride of nitrogen form upon the surface of the liquid, and ultimately sink to the bottom. The globules, as they descend, should be received in a small leaden saucer, placed under the mouth of the bottle for the purpose.
Prop., &c. Chloride of nitrogen should consequently be only prepared in very small quantities at a time. Both its discoverer and Sir H. Davy met with severe injuries while experimenting on it. Its sp. gr. is 1·653; it volatilises at 160° Fahr., and between 200° and 212° fulminates violently. Contact with combustible bodies at ordinary temperatures immediately causes detonation. The explosive power of this compound seems to exceed that of every known substance, not even excepting fulminating silver: A minute globule, no larger than a grain of mustard seed, placed on a platina spoon, and touched with a piece of phosphorus stuck on the point of a penknife, immediately explodes, and shivers the
blade into fragments, at the same time that the vessel that contains it is broken to pieces. Olive oil, naphtha, and oil of turpentine, have a similar effect. See Nitrogen, Iodide of (below).
Nitrogen, I′odide of. NI2. Syn. Nitrogen tri-iodide, Teriodide of nitrogen. A dark brown or black insoluble powder, which is most safely and conveniently prepared by saturating alcohol (sp. gr. ·852) with iodine, adding a large quantity of the strongest pure solution of ammonia, and agitating the mixture; water must now be added, when iodide of nitrogen will be precipitated, and must be carefully washed with cold distilled water. The filter containing the precipitate should be spread out on a sheet of glass and torn into small pieces while the iodide is still moist. The precipitate should be simply exposed to air only.
Prop., &c. It detonates violently as soon as it becomes dry, by the slightest pressure or friction, even that of a feather, and often spontaneously; but this explosion is scarcely so powerful as that of the chloride of nitrogen. It also explodes whilst moist, though less readily. It should only be prepared in very small quantities at a time. Recent researches induce the belief that both the above compounds contain hydrogen.
Nitrogen, Ox′ides of. Nitrogen forms 5 distinct compounds with oxygen.
1. Nitrous ox′ide. Syn. Protoxide of nitrogen; Lauging gas; Nitrogenii protoxydum, L. Prep. From fused nitrate of ammonium, introduced into a glass retort, or a flask furnished with a bent tube, and then exposed, over a spirit-lamp, or charcoal-chauffer, to a temperature of about 389° Fahr.; the evolved gas may be collected in bladders, gas-bags, a gasometer, or in the pneumatic trough over warm water. The gas may be purified by pouring it through three wash-bottles, one containing water, one a solution of sulphate of iron, and the other a solution of potassa.