1. Its color was orange red,[148]and its smell exactly resembled that of oxygenated muriatic acid.2. When agitated in boiled water, it was rapidly absorbed, leaving a residuum of rather more than one twelfth.3. The taper burnt in it with increased brilliancy, the flame being long, and deep red at the edges.4. Iron introduced into it ignited, burnt with a dull red light.5. Green vegetables exposed to it were instantly rendered white.6. It underwent no diminution, mingled with atmospheric air.7. When mingled with nitrous gas, it gave dense red vapor, and rapid diminution.
1. Its color was orange red,[148]and its smell exactly resembled that of oxygenated muriatic acid.
2. When agitated in boiled water, it was rapidly absorbed, leaving a residuum of rather more than one twelfth.
3. The taper burnt in it with increased brilliancy, the flame being long, and deep red at the edges.
4. Iron introduced into it ignited, burnt with a dull red light.
5. Green vegetables exposed to it were instantly rendered white.
6. It underwent no diminution, mingled with atmospheric air.
7. When mingled with nitrous gas, it gave dense red vapor, and rapid diminution.
c.From the exhibition of these properties, it was evident that the gas produced during the solution of platina in aqua regia, chiefly consisted of oxygenated muriatic acid, or of a gas highly analogous to it. It was, however, difficult to conceive how a body, by combining with a portion of the oxygene of nitro-muriatic acid, could produce from it oxygenated muriatic acid, apparently mingled with very small portions of any other gas.
d.To ascertain whether any permanent gas was produced during the ebullition of aqua regia, of the same composition as that used for the solution of the platina; I kept a large quantity of it boiling for some time, in communication with the water apparatus; the gas generated appeared to be wholly nitro-muriatic, and was absorbed as fast as produced, by the water.
e.To determine whether any nitrous oxide was mingled with the peculiar gas, as well as the nature and quantity of the unabsorbable gas, nitrous gas was gradually added to 21 cubic inches of the gasproduced from a new solution, till the diminution was complete: the gas remaining equalled 2,3 cubic inches; it was unabsorbable by water, and extinguished flame.
In another experiment, when the last portions of gas from a solution were carefully received in water previously boiled, 12 cubic inches agitated in water left a residuum of 1.3; whilst the same quantity decomposed by nitrous gas, containing,02 nitrogene, left about 1.5.
Hence it appeared that the aëriform products of the solution consisted of the peculiar gas analogous to oxygenated muriatic acid, and of a small quantity of nitrogene.
f.Consequently a portion of the nitric acid of the aqua regia had been decomposed; but if it had given oxygene both to the platina and muriatic acid, the quantity of nitrogene evolved ought to have been much more considerable.
g.To ascertain if any water had been decomposed, and the nitrogene condensed in the solution by its hydrogene, to form ammoniac, I saturated a solution with lime, and heated it, but no ammoniacal smell was perceived.
h.To determine if any nitrogene had entered into chemical combination with muriatic acid and oxygene, so as to form an aëriform triple compound, analogous in its properties to oxygenated muriatic acid, I exposed some of the gas to mercury, expecting that this substance, by combining with its oxygene, would effect a complete decomposition; and this was actually the case: for the gas was at first rapidly diminished, and the mercury became oxydated; its volume, however, soon increased; and the residual gas appeared to be nitrous, mingled with much nitrogene. The exact proportions of each, from an accident, I could not determine.
This experiment was inconclusive, because the nitro-muriatic acid suspended in the peculiar gas, from which it can probably be never perfectly freed, acted in common with it upon the mercury, and produced nitrous gas: and this nitrous gas, at the moment of its production, formed nitrous acid by combining with the oxygene of the peculiar gas;and the nitrous acid generated[149]was again decomposed by the mercury; and hence nitrous gas evolved, and possibly some nitrogene.
i.Peculiar circumstances prevented me at this time from completely investigating the subject. It remains doubtful whether the gas consists simply of highly oxygenated muriatic acid and nitrogene,[150]produced by the decomposition of nitric acid from the coalescing affinities of platina and muriatic acid for oxygene; or whether it is composed of apeculiargas, analogous to oxygenated muriatic acid, and nitrogene, generated from some unknown affinities.[151]
XI.On the action of the Electric Spark on a mixtureof Nitrogene and Nitrous Gas.
Thinking it possible that nitrous gas and nitrogene might be made to combine by the action of the electric spark, so as to form nitrous oxide, I introduced 20 grain measures of each of them into a small detonating tube, graduated to grains, standing over mercury, and containing a very small quantity of cabbage juice rendered green by an alkali. After electric sparks had been passed through the gases for an hour and half, they were diminished to about 32, and the cabbage juice was slightly reddened. On introducing about 10 measures of hydrogene, and passing the electric spark through the whole, no inflammation or diminution was perceptible. Hence the condensation most probably arose wholly from the formation of nitrous acid,[152]by the more intimate union of the oxygene of nitrous gas with some of its nitrogene, as in the experiments of Priestley.
As the nascent nitrogene, in the decomposition of nitrate of ammoniac, combines with a portion of oxygene and nitrogene, to form nitrous oxide; it is probable that nitrous oxide may be produced during the passage of nitrous gas and ammoniac through a heated tube.
XII.General Remarks.
There are no reasons for supposing that nitrous oxide is formed in any of the processes of nature; and the nice equilibrium of affinity by which it is constituted, forbids us to hope for the power of composing it from its simple principles. We must be content to produce it, either directly or indirectly, from the decomposition of nitric acid. And as in the decomposition of nitrate of ammoniac, not only all the nitrogene of the nitric acid enters into the composition of the nitrous oxide produced, but likewise that of the ammoniac, this process is by far the cheapest, as well as the most expeditious. A mode of producing ammoniacat little expence, has been proposed by Mr. Watt. Condensed in the sulphuric acid, it can be easily made to combine with nitric acid, from the decomposition of nitre by double affinity. And thus, if the hopes which the experiments at the end of those researches induce us to indulge, do not prove fallacious, a substance which has been heretofore almost exclusively appropriated to the destruction of mankind, may become, in the hands of philosophy, a means of producing health and pleasurable sensation.