that that gas, whatever it may be, can burn without air, and in that
respect differs from a candle, which cannot burn without the air. And our
manner of doing this is as follows: I have here a glass vessel (G) which
is fitted with two platinum-wires (IK), through which I can apply
electricity; and we can put the vessel on the air-pump and exhaust the
air, and when we have taken the air out we can bring it here and fasten it
on to this jar (F), and let into the vessel that gas which was formed by
the action of the voltaic battery upon the water, and which we have
produced by changing the water into it, for I may go as far as this, and
say we have really, by that experiment, changed the water into that gas.
We have not only altered its condition, but we have changed it really and
truly into that gaseous substance, and all the water is there which was
decomposed by the experiment. As I screw this vessel (GH) on here (H), and
make the tubes well connected, and when I open the stop-cocks (HHH), if
you watch the level of the water (in F), you will see that the gas will
rise. I will now close the stop-cocks, as I have drawn up as much as the
vessel can hold, and being safely conveyed into that chamber, I will pass
into it an electric spark from this Leyden jar (L), when the vessel, which
is now quite clear and bright, will become dim. There will be no sound,
for the vessel is strong enough to confine the explosion. [A spark was
then passed through the jar, when the explosive mixture was ignited.] Did
you see that brilliant light? If I again screw the vessel on to the jar,
and open these stop-cocks, you will see that the gas will rise a second
time. [The stop-cocks were then opened.] Those gases [referring to the
gases first collected in the jar, and which had just been ignited by the
electric spark] have disappeared, as you see: their place is vacant, and
fresh gas has gone in. Water has been formed from them; and if we repeat
our operation [repeating the last experiment], I shall have another
vacancy, as you will see by the water rising. I always have an empty
vessel after the explosion, because the vapour or gas into which that
water has been resolved by the battery explodes under the influence of the
spark, and changes into water; and by-and-by you will see in this upper
vessel some drops of water trickling down the sides and collecting at the
bottom.
We are here dealing with water entirely, without reference to the
atmosphere. The water of the candle had the atmosphere helping to produce
it; but in this way it can be produced independently of the air. Water,
therefore, ought to contain that other substance which the candle takes
from the air, and which, combining with the hydrogen, produces water.
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