IV. Decomposition of Nitrous Oxide by Phosphorus.
a. Phosphorus introduced into pure nitrous oxide at common temperatures, is not at all luminous. It is capable of being fused, and even sublimed in it, without undergoing acidification, and without effecting any alteration in its composition.
About 2 grains of phosphorus were fused, and gradually sublimed, in 2 cubic inches of pure nitrous oxide, over mercury, by the heat of a burning lens. No alteration was produced in the volume of gas, and a portion of it absorbed by water, left a residuum of one twelfth only.
Phosphorus was sublimed in pure nitrous oxide over mercury, in a dark room, by an iron heated nearly to ignition; but no luminous appearance was perceptible, nor was any gas decomposed.
b. Phosphorus decomposes nitrous oxide at the temperature of ignition, with greater or less rapidity, according to the degree of heat. We have already seen, that when phosphorus in active inflammation is introduced into nitrous oxide, it burns with intensely vivid light.
Phosphorus was sublimed by a heated wire in a jar filled with nitrous oxide, standing over warm mercury. In this state of sublimation an iron heated dull red was introduced to it by being rapidly passed through the mercury; a light blue flame surrounded the wire, and disappeared as soon as it ceased to be red.
To phosphorus sublimed as before, in nitrous oxide, over warm mercury, a thick wire ignited to whiteness was introduced; a terrible detonation took place, and the jar was shattered in pieces.
By employing thick conical jars,[172] containing only a small quantity of nitrous oxide, I effected the detonation several times with safety; but on account of the great expansion of the elastic products, the jar was generally either raised from the mercury, or portions of gas were thrown out of it. Hence I was unable to ascertain the exact changes produced by this mode of decomposition.
c. As my first attempts to ascertain the constitution of nitrous oxide were made on its decomposition by phosphorus, I employed many different modes of partially igniting this substance in it over mercury, so as to produce a combustion without explosion.
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.