Hydrogen, . . . . 3/4 grains. 1/12 ounce.
Oxygen, . . . . 11 9/10 1 1/3
Nitrogen, . . . . 10 4/10 1 1/6
Air,. . . . . . 10 7/10 1 1/5
Carbonic acid, . . 16 1/3 1 9/10
A pint of it weighs 161 3 grains, and a cubic foot weighs 19 10 ounce,
almost two ounces. You can see by many experiments that this is a heavy
gas. Suppose I take a glass containing nothing else but air, and from this
vessel containing the carbonic acid I attempt to pour a little of this gas
into that glass; I wonder whether any has gone in or not. I cannot tell by
the appearance, but I can in this way [introducing the taper]. Yes, there
it is, you see; and if I were to examine it by lime-water, I should find
it by that test also. I will take this little bucket, and put it down into
the well of carbonic acid indeed, we too often have real wells of
carbonic acid and now, if there is any carbonic acid, I must have got to
it by this time, and it will be in this bucket, which we will examine with
a taper. There it is, you see; it is full of carbonic acid.
[Illustration: Fig. 30.]
There is another experiment by which I will shew you its weight. I have
here a jar suspended at one end of a balance it is now equipoised; but
when I pour this carbonic acid into the jar on the one side which now
contains air, you will see it sink down at once, because of the carbonic
acid that I pour into it. And now, if I examine this jar with the lighted
taper, I shall find that the carbonic acid has fallen into it, and it no
longer has any power of supporting the combustion. If I blow a
soap-bubble, which of course will be filled with air, and let it fall into
this jar of carbonic acid, it will float.
[Illustration: Fig. 31.]
But I shall first of all take one of these little balloons filled with
air. I am not quite sure where the carbonic acid is; we will just try the
depth, and see whereabouts is its level. There, you see, we have this
bladder floating on the carbonic acid; and if I evolve some more of the
carbonic acid, the bladder will be lifted up higher. There it goes the
jar is nearly full; and now I will see whether I can blow a soap-bubble on
that, and float it in the same way. [The Lecturer here blew a soap-bubble,
60