DIVISION V.
EXPERIMENTS and OBSERVATIONS on the production of NITROUS OXIDE from NITROUS GAS and NITRIC ACID, in different modes.
I. Preliminaries.
a.
The opinions of Priestley[132] and Kirwan,[133] relating to the causes of the conversion of nitrous gas into nitrous oxide, were founded on the theory of phlogiston. The first of these philosophers obtained nitrous oxide by placing nitrous gas in contact with moistened iron filings, or the alkaline sulphures. The last by exposing it to sulphurated hydrogene.
The Dutch chemists,[134] the latest experimentalists on nitrous oxide, have supposed that the production of this substance depends upon the simple abstraction of a portion of the oxygene of nitrous gas. They obtained nitrous oxide by exposing nitrous gas to muriate of tin, to copper in solution of ammoniac, and likewise by passing it over heated sulphur.
The diminution of volume sustained by nitrous gas during its conversion into nitrous oxide, has never been accurately ascertained; it has generally been supposed to be from two thirds to eight tenths.
b. Nitrous gas may be converted into nitrous oxide in two modes.
First, by the simple abstraction of a portion of its oxygene, by bodies possessing a strong affinity for that principle, such as alkaline sulphites, muriate of tin, and dry sulphures.
Second, by the combination of a body with a portion both of its oxygene and nitrogene, such as hydrogene, when either in a nascent form, or a peculiar state of combination.
c. Each of these modes will be distinctly treated of; and to prevent unnecessary repetitions, I shall give an account of the general manner in which the following experiments on the conversion of nitrous gas into nitrous oxide, have been conduced.
Nitrous gas, the purity of which has been accurately ascertained by solution of muriate of iron, is introduced into a graduated jar filled with dry mercury. If a fluid substance is designed for the conversion of the gas into nitrous oxide, it is heated, to expel any loosely combined air which might be liberated during the process; and then carefully introduced into the jar, by means of a small phial. After the process is finished, and the diminution accurately noted, the nitrous oxide formed is absorbed by pure water. If any nitrous gas remains, it is condensed by solution of muriate of iron; other residual gases are examined by the common tests. The quantity of nitrous oxide dissolved by the fluid is determined by a comparative experiment; and the corrections for temperature and pressure being guessed at, the conclusions drawn.
If a solid substance is used, rather more nitrous gas than that designed for the conversion, is introduced into the jar. The substance is brought in contact with the gas, by being carried under the mercury; and as a little common air generally adheres to it, a small portion of the nitrous gas is transferred into a graduated tube, after the insertion, and its purity ascertained. In other respects the process is conducted as mentioned above.
II. Of the conversion of Nitrous gas into Nitrous Oxide,
by Alkaline Sulphites.
The alkaline sulphites, particularly the sulphite of potash, convert nitrous gas into nitrous oxide, with much greater rapidity than any other bodies.
At temperature 46°, 16 cubic inches of nitrous gas were converted, in less than an hour, into 7,8 of nitrous oxide, by about 100 grains of pulverised sulphite of potash, containing its water of crystalisation. No sensible increase of temperature was produced during the process, no water was decomposed, and the quantity of nitrogene remaining after the experiment, was exactly equal to that previously contained in the nitrous gas.
The nitrous oxide produced from nitrous gas by sulphite of potash, has all the properties of that generated from the decomposition of nitrate of ammoniac. It gives, as will be seen hereafter, the same products by analysis. Phosphorus, the taper, sulphur, and charcoal, burn in it with vivid light. It is absorbable by water, and capable of expulsion from it unaltered, by heat.
Nitrous gas is converted into nitrous oxide by the alkaline sulphites with the same readiness, whether exposed to the light, or deprived of its influence.
The solid sulphites act upon nitrous gas much more readily than their concentrated solutions; they should however always be suffered to retain their water of crystalisation, or otherwise they attract moisture from the gas, and render it drier, and in consequence more condensed than it would otherwise be. In case perfectly dry sulphites are employed, the gas should be always saturated with moisture after the experiment, by introducing into the cylinder a drop of water.
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.
This singular exertion of attractions by a simple body, appears highly improbable a priori, nor did I admit it, till the formation of ammoniac, and the non-oxygenation of the sulphur, were made evident by many experiments.
In those experiments, the diminution of the nitrous gas was not uniformly the same. It varied from ¹¹/₂₀ to ¹⁴/₂₀. In the most accurate of them, 5 cubic inches of nitrous gas were converted into 2.2 of nitrous oxide. Consequently the quantity of ammoniac formed was,047 grains.
In experiments on the conversion of nitrous gas into nitrous oxide, by sulphurated hydrogene, the gases should be rendered as dry as possible. The presence of water considerably retards the decomposition.
b. The sulphures[137] dissolved in water convert nitrous gas into nitrous oxide. This decomposition is not, however, produced by the simple abstraction of oxygene from the nitrous gas to form sulphuric acid. It depends as well on the decomposition of the sulphurated hydrogene dissolved in the solution, or liberated from it. In this process sulphur is deposited on the surface of the fluid, sulphuric acid is formed, and the diminution, making the necessary corrections, is nearly the same as when free sulphurated hydrogene is employed.
It is extremely probable that sulphurated hydrogene, in combination with the alkalies, as well as with water, is capable of being slowly decomposed by nitrous gas.
V. Decomposition of Nitrous Gas by Nascent Hydrogene.
a. When nitrous gas, is exposed to wetted iron filings, a diminution of its volume slowly takes place; and after a certain time, it is found converted into nitrous oxide.
In this process ammoniac[138] is formed, and the iron partially oxydated.
The water in contact with the iron is decomposed by the combination of its oxygene with that substance, and of its hydrogene with a portion of the oxygene and nitrogene of the nitrous gas, to form water and ammoniac.
That the iron is not oxydated at the expence of the oxygene of the nitrous gas, appears very probable from the analogy between this process, and the mutual decomposition of nitrous gas and sulphurated hydrogene. Besides, dry iron filings effect no change whatever in nitrous gas, at common temperatures.
I have generally found about 12 of nitrous gas converted into 5 of nitrous oxide in this process; which is not very different from the diminution by sulphurated hydrogene. It takes place equally well in light and darkness; but more rapidly in warm weather than in cold.
b. Nitrous gas exposed to a large surface of zinc, in contact with water, is slowly converted into nitrous oxide; at the same time that ammoniac is generated, and white oxide of zinc formed. This process appears to depend, like the last, upon the decomposition of water by the affinities of part of the oxygene and nitrogene of nitrous gas, for its hydrogene, to form ammoniac and water; and by that of zinc for its oxygene. Zinc placed in contact with water, and confined by mercury,[139] decomposes it at the common temperature. Zinc, when perfectly dry, does not in the slightest degree act upon nitrous gas.
I have not been able to determine exactly the diminution of volume of nitrous gas, during its conversion into nitrous oxide by zinc. In one experiment 20 measures of nitrous gas, containing about,03 nitrogene, were diminished to 9, after an exposure of eight days to wetted zinc; but from an accident, I was not able to ascertain the exact quantity of nitrous oxide formed.
c. It is probable that most of the imperfect metals will be found capable of oxydation, by the decomposition of water, when its hydrogene is attracted by the oxygene and nitrogene of nitrous gas. I have this day (April 14, 1800), examined two portions of nitrous gas, one of which had been exposed to copper filings, and the other to powder of tin, for twenty-three days.
The gas that had been exposed to copper was diminished nearly two fifths. The taper burnt in it with an enlarged flame, blue at the edges. Hence it evidently contained nitrous oxide.
The nitrous gas in contact with tin had undergone a diminution of one fourth only, and did not support flame.
VI. Miscellaneous Observations on the conversion
of Nitrous Gas into Nitrous Oxide.
a. Dr. Priestley found nitrous gas exposed to a mixture of iron filings and sulphur, with water, converted after a certain time, into nitrous oxide. Sulphurated hydrogene is always produced during the combination of iron and sulphur, when they are in contact with water; and by the hydrogene of this in the nascent state, the nitrous gas is most probably decomposed.
b. Green oxide of iron moistened with water, exposed to nitrous gas, slowly gains an orange tinge, whilst the gas is diminished. Most likely it is converted into nitrous oxide; but this I have not ascertained.
c. I exposed nitrous gas, to the following bodies over mercury for many days, without any diminution, or apparent change in its properties. Alcohol, saccharine matter, hydrocarbonate, sulphureous acid, and phosphorus.
d. Crystalised sulphate, and muriate of iron, absorb a small quantity of nitrous gas, and become dark colored on the outside; but after this absorption, (which probably depends on their water of crystalisation,) has taken place, no change is effected in the gas remaining.
e. The power of iron to decompose water being much increased by increase of temperature, nitrous gas is converted into nitrous oxide much more rapidly when placed in contact with a surface of heated iron, than when exposed to it at common temperatures. During the decomposition of nitrous gas in this way, ammoniac[140] is formed.
f. The curious experiments of Rouppe,[141] on the absorption of gases by charcoal, compared with the phænomena noticed in this Division, render it probable that hydrogene in a state of loose combination with charcoal, will be found to convert nitrous gas into nitrous oxide.
VII. Recapitulation of conclusions concerning the
conversion of Nitrous Gas into Nitrous Oxide.
a. Certain bodies having a strong affinity for oxygene, as the sulphites, dry sulphures, muriate of tin, &c. convert nitrous gas into nitrous oxide, by simply attracting a portion of its oxygene; whilst the remaining oxygene enters into combination with the nitrogene, and they assume a more condensed state of existence.
b. Nitrous gas is converted into nitrous oxide by hydrogene, in a peculiar state of existence, as in sulphurated hydrogene; and that by a series of very complex affinities. Both oxygene and nitrogene are attracted from the nitrous gas by the hydrogene, in such proportions as to form water and ammoniac, whilst the remaining oxygene and nitrogene[142] assume the form of nitrous oxide.
c. Nitrous gas placed in contact with bodies, such as iron and zinc decomposing water, is converted into nitrous oxide, at the same time that ammoniac is formed. It is difficult to ascertain the exact rationale of this process. For either the nascent hydrogene produced by the decomposition of the water by the metallic substance may combine with portions of both the oxygene and nitrogene of the nitrous gas; and thus by forming water and ammoniac, convert it into nitrous oxide. Or the metallic substance may attract at the same time oxygene from the water and nitrous gas, whilst the nascent hydrogene of the water seizes upon a portion of the nitrogene of the nitrous gas to form ammoniac.
The degree of diminution, and the analogy between this process and the decomposition of nitrous gas by sulphurated hydrogene, render the first opinion most probable.
VIII. The production of Nitrous Oxide during the
oxydation of Tin, Zinc, and Iron, in Nitric Acid.
a. Dr. Priestley discovered, that during the solution of tin, zinc, and iron, in nitric acid, certain portions of nitrous oxide were produced, mingled with quantities of nitrous gas, and nitrogene, varying in proportion as the acid employed was more or less concentrated.
It has long been known that ammoniac is formed during the solution of tin, zinc, and iron, in diluted nitric acid. Consequently, in these processes water is decomposed.
I had designed to investigate minutely these phænomena, so as to ascertain the quantities of water and acid decompounded, and of the new products generated. But after going through some experiments on the oxydation of tin without gaining conclusive results, the labor, and sacrifice of time they demanded, obliged me to desist from pursuing the subject, till I had completed more important investigations.
I shall detail the few observations which have occurred to me, relating to the production of nitrous oxide from metallic solutions.
b. When tin is dissolved in concentrated nitric acid, such as of 1.4, nitrous oxide is produced, mingled with generally more than twice its bulk of nitrous gas. In this process but little free nitrogene is evolved, and the tin is chiefly precipitated in the form of a white powder. If the solution, after the generation of these products, is saturated with lime, and heated, the ammoniacal smell is distinct.
When nitric acid of specific gravity 1.24, is made to act upon tin; in the beginning of the process, nearly equal parts of nitrous gas and nitrous oxide are produced; as it advances, the proportion of nitrous oxide to the nitrous gas increases: the largest quantity of nitrous oxide that I have found in the gas procured from tin is ¾, the remainder being nitrous gas and nitrogene.
When tin is oxydated in an acid of less specific gravity than 1.09, the quantities of gas disengaged are very small, and consist of nitrogene, mingled with minute portions of nitrous oxide, and nitrous gas.
Whenever I have saturated solutions of tin in nitric acid of different specific gravities, with lime, and afterwards heated them, the ammoniacal smell has been uniformly perceptible, and generally most distinct when diluted acids have been employed.
c. When zinc is dissolved in nitric acid, whatever is its specific gravity, certain quantities of nitrous oxide are produced.
Nitric acids of greater specific gravity than 1.2, act upon zinc with great rapidity, and great increase of temperature. The gases disengaged from these solutions consist of nitrous gas, nitrous oxide, and nitrogene; the nitrous oxide rarely equals one third of the whole.
When nitric acid of 1,104 is made to dissolve zinc, the gas obtained in the middle of the process consists chiefly of nitrous oxide. From such a solution I obtained gas which gave a residuum of one sixth only when absorbed by water. The taper burnt in it with a brilliant flame, and sulphur with a vivid rose-colored light.
100 grains of granulated zinc, during their solution in 300 grains of nitric acid, of 1,43, diluted with 14 times its weight of water, produced 26 cubic inches of gas. Of this gas ⁷/₃₆ were nitrous, ¹⁷/₃₆36 nitrous oxide, and the remainder nitrogene. The solution saturated with lime and heated, gave a distinct smell of ammoniac.
d. During the solution of iron in concentrated nitric acid, the gas given out is chiefly nitrous; it is however generally mingled with minute quantities of nitrous oxide. When very dilute nitric acids are made to act upon iron, by the assistance of heat, nitrous oxide is produced in considerable quantities, mingled with nitrous gas and nitrogene; the proportions of which are smaller as the process advances.[143] The fluid remaining after the oxydation and solution of iron in nitric acid, always contains ammoniac.
e. As during the solution of tin, zinc, and iron, in nitric acid, the quantity of acid is diminished in proportion as the process advances, it is reasonable to suppose that the relative quantities of the gases evolved are perpetually varying. In the beginning of a dissolution, the nitrous gas generally predominates, in the middle nitrous oxide, and at the end nitrogene.
f. During the generation of nitrous gas, nitrous oxide, and ammoniac, from the decomposition of solution of nitric acid in water, by tin, zinc, and iron, very complex attractions must exist between the constituents of the substances employed. The acid and the water are decomposed at the same time, and in proportions different as the solution is more concentrated, by the combination of their oxygene with the metallic body.
The nitrous gas is produced by the combination of the metal with ³²/₁₀₀ of the oxygene of the acid. The nitrous oxide is most probably generated by the decomposition of a portion of the nitrous gas disengaged, by the nascent hydrogene of the water decompounded; some of it may be possibly formed from a more complete decomposition of the acid.
The production of ammoniac may arise, probably from two causes; from the decomposition of the nitrous gas by the combination of the nascent hydrogene of the water, with portions of its oxygene and nitrogene at the same time; and from the union of hydrogene with nascent nitrogene liberated in consequence of a complete decomposition of part of the acid.
IX. Additional Observations on the production
of Nitrous Oxide.
a. When nitric acid is combined with muriatic acid, or sulphuric acid,[144] the quantities of nitrous oxide produced from its decomposition by tin, zinc, and iron, are rather increased than diminished. The nitrous oxide obtained from these solutions is, however, never sufficiently pure for physiological experiments. It is always mingled with either nitrous gas, nitrogene, or hydrogene, and sometimes with all of them.
b. From the solutions of bismuth, nickel, lead, and copper, in diluted nitric acid, I have never obtained any perceptible quantity of nitrous oxide: the gas produced is nitrous, mingled with different portions of nitrogene. Antimony and mercury, during their solution in aqua regia, give out only nitrous gas.
Probably none of the metallic bodies, except those that decompose water at temperatures below ignition, will generate nitrous oxide from nitric acid. On cobalt and manganese I have never had an opportunity of experimenting: manganese will probably produce nitrous oxide.
c. During the solution of vegetable matters[145] in nitric acid, by heat, very minute portions of nitrous oxide are sometimes produced, always however mingled with large quantities of nitrous gas, and carbonic acid.
When nitric acid is decompounded by ether, fixed oils, volatile oils, or alcohol, towards the end of the process small quantities of nitrous oxide are produced, and sometimes sufficiently pure to support the flame of the taper.[146]
d. When green oxide of iron is dissolved in nitric acid, nitrous oxide is produced, mingled with nitrogene and nitrous gas.
e. During the conversion of green sulphate, or green muriate of iron into red, by the decomposition of dilute nitric acid, nitrous oxide is formed, mingled with different proportions of nitrous gas and nitrogene.
f. When solution of green nitrate of iron is heated, a part of the acid is decomposed, red oxide is precipitated, red nitrate formed, and impure nitrous oxide evolved.
g. When iron is introduced into a solution of nitrate of copper, the copper is precipitated in its metallic state, whilst nitrous oxide, mingled with small portions of nitrogene, is produced.[147]
Both zinc and tin precipitate copper in its metallic form from solution in the nitric acid. During these precipitations, certain quantities of nitrous oxide are generated, mingled however with larger quantities of nitrogene than that produced from decomposition by iron. In all these processes ammoniac is formed, and water consequently decomposed.
The decomposition of water and nitric acid, during the precipitation of copper from solution of nitrate of copper, by tin, zinc, and iron, depends upon the strong affinity of those metals for oxygene, and their powers of combining with a larger quantity of it than copper.
X. Decomposition of Aqua Regia by Platina, and
evolution of a Gas analogous to Oxygenated
Muriatic Acid, and Nitrogene.
a. De la Metherie, in his essay on different airs, has asserted that the gas produced by the solution of platina in nitro-muriatic acid, is identical with the dephlogisticated nitrous gas of Priestly. He calls it nitrous gas with excess of pure air, and affirms that it diminishes, both with nitrous gas and common air.
b. I introduced into a vessel containing 30 grains of platina, 2050 grains of aqua regia, composed of equal parts, by weight, of concentrated nitric acid of 1,43, and muriatic acid of 1,16. At the common temperature, that is, 49°, no action between the acid and platina appeared to take place. On the application of the heat of a spirit lamp, the solution gradually became yellow red, and gas was given out with rapidity. Some of this gas received in a jar filled with warm water, appeared of a bright yellow color. On agitation, the greater part of it was absorbed by the water, and the remainder extinguished flame. When it was received over mercury, it acted upon it with great rapidity, and formed on the surface a white crust.
As the process of solution advanced, the color of the acid changed to dark red, at the same time that the production of gas was much increased; more than 40 cubic inches were soon collected in the water apparatus.
Different portions of the gas were examined, it exhibited the following properties:
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 gas produced 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 a peculiar gas, analogous to oxygenated muriatic acid, and nitrogene, generated from some unknown affinities.[151]
XI. On the action of the Electric Spark on a mixture
of 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 ammoniac at 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.