_a._ 12 measures of muriatic acid gas were mingled with 7 measures
of nitrous oxide at 56°. After remaining together for a minute, they
filled a space equal to 19½ measures. When water was introduced to
them, the muriatic acid was absorbed much more slowly than if it had
been unmingled.
In another experiment, when the gases were saturated with water, 9
measures of each of them, when mingled and suffered to remain in
contact for a quarter of an hour, filled a space nearly equal to 19;
and after the muriatic acid had been absorbed by potash, the nitrous
oxide remained unaltered in its properties.
From the expansion, it appears most probable that aëriform muriatic
acid, and nitrous oxide, have a certain affinity for each other, and
that they combine when mingled together; for in the last experiment,
the increase of volume cannot be accounted for by supposing that
nitrous oxide undergoes less change of volume than muriatic acid,
by aëriform combination with water, and that the expansion depended
upon the solution of some of its combined water by the muriatic acid.
That muriatic acid and nitrous oxide have a slight affinity for each
other, likewise appears from the absorption of nitrous oxide by aqueous
solution of muriatic acid.
Thinking that nitrous oxide might attract muriatic acid from its
solution in water, I exposed a minute quantity of fluid muriatic acid
to nitrous oxide; but no alteration of volume took place in the gas.
_b._ 6 measures of nitrous oxide were mingled with 11 measures of
sulphureous acid, saturated with water; after remaining at rest for six
minutes, they filled a space nearly equal to 18 measures. Exposed to
water, the sulphureous acid was absorbed, but not nearly so rapidly as
when in a free state. Sulphur burnt with a vivid flame in the residual
nitrous oxide. 7 measures of sulphureous acid were now mingled with
8 of nitrous oxide. They filled a space nearly equal to 15¾, and no
farther expansion took place afterwards.
From these experiments it appears probable that sulphureous acid, and
nitrous oxide, have some affinity for each other.
_c._ 11 measures of carbonic acid were mingled with 8 of nitrous
oxide; they filled a space nearly equal to 19 measures. On exposing
the mixture to caustic potash, the carbonic acid was absorbed, and the
nitrous oxide remained pure. Hence it appears that carbonic acid and
nitrous oxide do not combine with each other.
_d._ Oxygenated muriatic acid, and nitrous oxide, were mingled in a
water apparatus: there was a slight appearance of condensation; but
this was most probably owing to absorption by the water; on agitation,
the oxygenated muriatic acid was absorbed, and the greater part of the
nitrous oxide remained unaltered.
_e._ Sulphurated hydrogene and nitrous oxide, mingled together, neither
expanded or contracted; exposed to solution of potash, the acid[154]
only was absorbed.
[154] The experiments of Berthollet have clearly proved the perfect
acidity of this substance.
_f._ 10 measures of nitrous gas were admitted to 12 of nitrous oxide at
59°. They filled a space equal to 22, and after remaining together for
an hour, had undergone no change. Solution of muriate of iron absorbed
the nitrous gas without affecting the nitrous oxide.
_g._ Nitrous oxide was successively mingled with oxygene, atmospheric
air, hydrocarbonate, phosphorated hydrogene, hydrogene, and nitrogene,
at 57°; it appeared to possess no action on any of them, and was
separated by water, the gases remaining unaltered.
_h._ As nitrous oxide was soluble in ether, alcohol, and the other
inflammable fluids, it was reasonable to suppose that its affinity for
those bodies would enable them to unite with it in the aëriform state.
At the suggestion of Dr. Beddoes I made the following experiment:
To 12 measures of nitrous oxide, at 54°, I introduced a single drop of
ether; the gas immediately began to expand, and in four minutes filled
a space equal to sixteen measures and a quarter. When an inflamed taper
was plunged into the gas thus holding ether in solution, a light blue
flame slowly passed through it.
A considerable diminution of temperature is most probably produced,
from the great expansion of nitrous oxide during its combination with
ether.
A drop of alcohol was admitted to 14 measures of nitrous oxide. In five
minutes, the gas filled a space equal to fifteen and a third; but no
farther diminution took place afterwards.
A minute quantity of oil of turpentine was introduced to 14 measures
of nitrous oxide; it filled, in 4 minutes, a space rather less than
14; and no farther change took place afterwards. Most likely this
contraction arose from the precipitation of the water dissolved in the
gas by the stronger affinity of the oil for nitrous oxide. To ascertain
with certainty if any oil had been dissolved by the gas, I introduced
into it a small quantity of ammoniac. It immediately became slightly
clouded, most probably from the formation of soap, by the combination
of the dissolved oil with the ammoniac.
From these experiments we learn, that when nitrous oxide is mingled
with either carbonic acid, oxygene, common air, hydrocarbonate,
sulphurated hydrogene, hydrogene, or nitrogene, they may be separated
from each other without making any allowance for contraction or
expansion; but if a mixture of either muriatic acid, or sulphureous
acid gas, with nitrous oxide, is experimented upon; in the absorption
of the acid by alkalies, the apparent volume of gas condensed will be
less than the real one, by a quantity equal to the sum of expansion
from combination. Consequently a correction must be made on account of
this circumstance.
Though alcohol, ether, essential oils, and the fluid inflammable
bodies in general, dissolve nitrous oxide with much greater rapidity
than water, yet as we are not perfectly acquainted with their action on
unabsorbable gases, it is better to employ water for separating nitrous
oxide from these substances; particularly as that fluid is more or less
combined with all gases, and as we are acquainted with the extent of
its action upon them.
By pursuing the subject of the solution of essential oils in gases,
we may probably discover a mode of obtaining them in a state of
absolute dryness. For if other gases as well as nitrous oxide, have a
stronger affinity for oils than for water, water most probably will
be precipitated from them during their solution of oils; and after
their saturation with oil, it is likely that they are capable of being
deprived of that substance by ammoniac.
VI. _Action of aëriform Nitrous Oxide in the Alkalies. History of the
discovery of the combinations of Nitrous Oxide with the Alkalies._
_a._ When nitrous oxide in a free state is exposed to the solid caustic
alkalies and alkaline earths, at common temperatures, it is neither
absorbed nor acted upon; when it is placed in contact with solutions
of them in water, a small quantity is dissolved; but this combination
appears to depend on the water of the solution, for the gas can be
expelled unaltered, at the temperature of ebullition.
_b._ Caustic potash was exposed to nitrous oxide for 13 hours: the
diminution was not to one fiftieth, and this slight condensation most
probably depended upon its combination with the water of the gas.
Concentrated solution of potash absorbed a fourth of its bulk of
nitrous oxide. When the impregnated solution was heated, globules of
gas were given out from it rapidly; but the quantity collected was too
small to examine.
Soda, whether solid or in solution, exhibited exactly the same
phænomena with nitrous oxide. The solution of soda absorbed near a
quarter of its bulk of gas.
_c._ 11 measures of ammoniacal gas were mingled with 8 measures of
nitrous oxide over dry mercury, both of the gases being saturated with
water. No change of appearance was produced by the mixture, and they
filled, after two minutes, a space equal to 19. On the introduction
of a little water, the ammoniac was absorbed, and the nitrous oxide
remained unaltered, for it was dissolved by water as rapidly as if it
had never been mingled with ammoniac.[155]
[155] The Dutch chemists have asserted, that mixture with ammoniac
prevents the absorption of nitrous oxide by water, either wholly or
partially. Journal de Physique, t. xliii. part ii. pag. 327. It is
difficult to account for their mistake.
7 measures of nitrous oxide, exposed to 6 measures of solution of
ammoniac in water, was in an hour diminished to 4½ nearly. When the
solution was heated over mercury, permanent gas was produced, which
was unabsorbable by a minute quantity of water, and soluble in a large
quantity; consequently it was nitrous oxide.
_d._ Nitrous oxide was exposed to dry caustic strontian; it underwent a
diminution of nearly one fortieth, which most likely was owing to the
combination of the strontian with its water.
11 measures of nitrous oxide were agitated in contact with 8 of
strontian lime water: nearly 4 measures were absorbed. The impregnated
solution exposed to heat, rapidly gave out its gas; 3 measures were
soon collected, which mingled with a small quantity of hydrogene, and
inflamed by the taper, gave a smart detonation.
_e._ Nitrous oxide exposed to lime and argil, both wet and dry, was not
in the slightest degree acted upon.
From these experiments it is evident that nitrous oxide in the aëriform
state cannot be combined either with the alkalies, or the alkaline
earths. That a combination may be effected between nitrous oxide and
these substances, it must be presented to them, in the _nascent state_.
The salts composed of the alkalies and nitrous oxide, are not
analogous to any other compound substances, being possessed of very
singular properties. Before these properties are detailed, it may not
be amiss to give an account of the accidental way in which I discovered
the mode of combination.
In December, 1799, designing to make a very delicate experiment, with
a view to ascertain if any water was decomposed during the conversion
of nitrous gas into nitrous oxide, by sulphite of potash, I exposed
200 grains of crystalised sulphite of potash, containing great
superabundance of alkali, to 14 cubic inches of nitrous gas, containing
one eighteenth nitrogene. The alkali was employed to preserve any
ammoniac that might be formed, in the free state, as it would otherwise
combine with sulphureous acid.[156]
[156] Sulphureous acid saturates more potash than sulphuric acid, so
that most probably during the conversion of sulphite of potash into
sulphate, portions of sulphureous acid are disengaged.
The volume of gas diminished with great rapidity; in two hours and
ten minutes it was reduced to 6⁴/₅, which I considered as the limit
of diminution. Accidentally, however, suffering it to remain for three
hours longer, I was much surprised by finding that not quite 2 cubic
inches remained, which consisted of nitrous oxide, mingled with the
nitrogene that existed before the experiment.
In accounting theoretically for this phænomenon, different suppositions
necessarily presented themselves.
1st, It was possible, that though sulphite of potash, and potash,
separately possessed no action on free nitrous oxide, yet in
combination they might exert such affinities upon it as either to
absorb it, or make it enter into new combinations.
2dly. It was more probable that the caustic potash, though incapable
of condensing aëriform nitrous oxide, was yet possessed of a strong
affinity for it when in the _nascent state_, and that the nitrous oxide
condensed in the experiment had been combined in this state with the
free alkali.
To ascertain if the compound of potash and sulphite of potash with
sulphate, was capable of acting upon nitrous oxide, I suffered a
quantity of this substance to remain in contact with the gas for near a
day: no change whatever took place.
To determine whether the diminution of nitrous oxide depended upon its
absorption in the nascent state, by the peculiar compound of potash and
sulphite of potash, or if it was simply owing to the alkali.
I mingled a solution of sulphite of potash with caustic soda; the
salt, after being evaporated at a low temperature, was exposed to
nitrous gas. The nitrous oxide formed was absorbed, but in rather less
quantities than when alkaline sulphite of potash was employed.
Hence it was evident that the alkali was the agent that had condensed
the nitrous oxide in those experiments, for soda is incapable of
combining either with sulphate, or sulphite of potash.
To ascertain whether any change in the constitution of the nitrous
oxide had been produced by the condensation, I introduced a small
quantity of sulphite of potash, with excess of alkali, that had
absorbed nitrous oxide, into a long and thin cylindrical tube filled
with mercury; and inclining it at an angle of 35° with the plane of the
mercury, applied the heat of a spirit lamp to that part of the tube
containing the salts; when the glass became very hot, gas was given out
with rapidity; in less than a minute the tube was full. This gas was
transfered into another tube, and examined; it proved to be nitrous
oxide in its highest state of purity;[157] for a portion of it absorbed
by common water, left no more than a residuum of ¹/₁₅, and sulphur
burnt in it with a vivid rose-colored flame.
[157] Hence we learn that sulphite of potash, when strongly heated,
does not decompose nitrous oxide, even in the _nascent state_.
Being now satisfied that the alkalies were capable of combining with
nitrous oxide; to investigate with precision the nature of these new
compounds, I proceeded in the following manner.