The sulphites, after exposure to nitrous gas, are either found wholly, or partially, converted into sulphates. Consequently the conversion of nitrous gas into nitrous oxide by these bodies, simply depends on the abstraction of a portion of its oxygene; the nitrogene and remaining oxygene assuming a more condensed state of existence.
If we reason from the different specific gravities of nitrous oxide and nitrous gas, as compared with the diminution of volume of nitrous gas, during its conversion into nitrous oxide, 100 parts of nitrous gas, supposing the former estimation of the composition of nitrous oxide given in [Division III], accurate, would consist of 54 oxygene, and 46 nitrogene; which is not far from the true estimation. Or assuming the composition of nitrous gas, as given in [Division IV], it would appear from the diminution, that 100 parts of nitrous oxide consisted of 38 oxygene, and 62 nitrogene.
III. Conversion of Nitrous Gas into Nitrous Oxide,
by Muriate of Tin, and dry Sulphures.
a. Nitrous gas exposed to dry muriate of tin, is slowly converted into nitrous oxide: during this process the apparent diminution is to about one half; but if the products are nicely examined, and the necessary corrections made, the real diminution of nitrous gas by muriate of tin, will be the same as by the sulphites; that is, 100 parts of it will be converted into 48 of nitrous oxide.
During this conversion, no water is decomposed, and no nitrogene evolved. Solution of muriate of tin converts nitrous gas into nitrous oxide; but with much less rapidity than the solid salt.
b. Nitrous gas exposed to dry and perfectly well made sulphures, particularly such as are produced from crystalised alumn[135] and charcoal not sufficiently inflammable to burn in the atmosphere, is converted into nitrous oxide by the simple abstraction of a portion of its oxygene, and consequently undergoes a diminution of ⁵²/₁₀₀.
It is probable, that all the bodies having strong affinity for oxygene will, at certain temperatures, convert nitrous gas into nitrous oxide. Priestley, and the Dutch chemists, effected the change by heated sulphur. Perhaps nitrous gas sent through a tube heated, but not ignited, with phosphorus, would be converted into nitrous oxide.
IV. Decomposition of Nitrous Gas, by Sulphurated Hydrogene.
a. When nitrous gas and sulphurated hydrogene are mingled together, a decomposition of them slowly takes place. The gases are diminished, sulphur deposited, nitrous oxide formed, and signs of the production of ammoniac[136] and water perceived.
In this process no sulphuric, or sulphureous acid is produced; consequently none of the sulphur is oxydated, and of course the changes depend upon the combination of the hydrogene of the sulphurated hydrogene, with different portions of the oxygene and nitrogene of the nitrous gas, to form water and ammoniac, the remaining oxygene and nitrogene assuming the form of nitrous oxide.