[85] See the curious paper of this excellent philosopher, on the combustion of the diamond, in which he proves that charcoal is, in fact, oxide of diamond. Annales de Chimie, xxxi.
[86] This was actually the case; for on examining the conducting tube the day after the experiment, some minute crystals of prismatic nitrate of ammoniac were perceived in it.
[87] Owing part of their weight to an unknown quantity of water.
[88] Mem. de Paris. 1785, and Journal de Physique, 1786, page 175.
[89] The absorption of nitrous gas by sulphate of iron, &c. will be treated of in the next division.
[90] As is evident from the decomposition of ammoniac by heat.
[91] Nitric acid is phlogisticated by heat, as appears from Dr. Priestley’s experiments. Vol. 3, p. 26.
[92] As is evident from the increase of temperature required for the formation of water.
[93] For ammoniac and nitrous oxide are both decomposed at the red heat, and oxygene given out from nitric acid when it is passed through a heated tube.
[94] Whenever nitrous acid is produced at high temperatures, it is always highly phlogisticated, provided it has not been long in contact with oxygene. When Dr. Priestley passed nitric acid through a tube heated red, he procured much oxygene, and phlogisticated acid; and the water in the apparatus employed was fully impregnated with nitrous air. Hence it would appear, that heat diminishes the attraction between oxygene and nitrous gas, and increases the affinity of nitrous gas for nitrous acid. Mr. James Thomson, whose theory of the Nitrous Acid I have already mentioned, from some experiments on the phlogistication of Nitric Acid by heat, which he has communicated to me, concludes with great justness, that a portion of the acid is always completely decomposed in this process: the oxygene liberated, and the nitrous gas combined with the remaining acid.