All the solid and fluid compound inflammable bodies on which I have
experimented, burn in nitrous oxide, at high temperatures. Wood,
cotton, and paper, are easily inflamed in it by the burning glass.
During their combustion, nitrous acid is always formed, carbonic acid,
and water produced, and nitrogene evolved, rather less in bulk than the
nitrous oxide decomposed.
I have already mentioned that alcohol and ether are soluble in nitrous
oxide. When an ignited body is introduced into the solution of
alcohol, or ether in nitrous oxide, a slight explosion takes place.
XIV. _General Conclusions relating to the Decomposition of Nitrous
Oxide, and to its Analysis._
From what has been said in the preceding sections, it appears that
the inflammable bodies, in general, require for their combustion in
nitrous oxide, much higher temperatures than those at which they burn
in atmospheric air, or oxygene.
When intensely heated they decompose it, with the production of much
heat and light, and become oxygenated.
During the combustion of solid or fluid bodies, producing flame, in
nitrous oxide, nitrous acid is generated, most probably from a new
arrangement of principles, analogous to those observed in Sect. II, by
the ignition of that part of the gas not in contact with the burning
substance. Likewise when nitrous oxide in excess is decomcomposed by
inflammable gases, nitrous acid, and sometimes a gas analogous to
common air, is produced, doubtless from the same cause.
Pyrophorus is the only body that inflames in nitrous oxide, below the
temperature of ignition.
Phosphorus burns in it with the blue flame, probably forming with its
oxygene only phosphoreous acid at the dull red heat, and with the
intensely vivid flame, producing phosphoric acid at the white heat.
Hydrogene, charcoal, sulphur, iron, and the compound inflammable
bodies, decompose it only at heats equal to, or above, that of
ignition: _probably_ each a different temperature.
From the phænomena in Sect. V. it appears, that at the temperature of
intense ignition, phosphorus has a stronger affinity for the oxygene
of nitrous oxide than hydrogene; and reasoning from the different
degrees of combustibility of the inflammable bodies, in mixtures of
nitrous oxide and nitrogene, and from other phænomena, we may conclude
with probability, that at about the white heat, the affinity of the
combustible bodies for oxygene takes place in the following order.
Phosphorus, hydrogene, charcoal,[179] iron, sulphur, &c.
This order of attraction is very different from that obtaining at the
red heat; in which temperature charcoal and iron have a much stronger
affinity for oxygene than either phosphorus or hydrogene.[180]
[179] As is proved by the decomposition of oxide of iron and sulphuric
acid by charcoal, at that temperature.
[180] Hydrogene at or about the red heat, appears to attract oxygene
stronger than phosphorus. See Dr. Priestley’s experiments, vol. i. page
262.
The smallest quantity of oxygene given in the different analyses of
nitrous oxide just detailed, is thirty five hundred parts; the greatest
proportion is thirty-nine.
Taking the mean estimations from the most accurate experiments, we may
conclude that 100 grains of the known ponderable matter of nitrous
oxide, consist of about 36,7 oxygene, and 63,3 nitrogene; or taking
away decimals, of 37 oxygene to 63 nitrogene; which is identical with
the estimation given in Research I.