vapour, that the gas formed should be collected over the water-bath, &c.
In short, it is a very complicated affair. But the same effect may be
produced with the greatest facility, by the action of the Voltaic
battery, which this will give me an opportunity of exhibiting.

CAROLINE.

I am very glad of that, for I longed to see the power of this apparatus
in decomposing bodies.

MRS. B.

For this purpose I fill this piece of glass-tube (PLATE VIII. fig. 1.)
with water, and cork it up at both ends; through one of the corks I
introduce that wire of the battery which conveys the positive
electricity; and the wire which conveys the negative electricity is made
to pass through the other cork, so that the two wires approach each
other sufficiently near to give out their respective electricities.

[Illustration: Plate VIII. Vol. I. p. 206

Fig. 1. Apparatus for the decomposition of water by the Voltaic
Battery.

Fig. 2. Apparatus for decomposing water by Voltaic Electricity
& obtaining the gasses separate.

Fig. 3. Apparatus for preparing & collecting hydrogen gas.

Fig. 4. Receiver full of hydrogen gas inverted over water.

Fig. 5 Slow combustion of hydrogen gas.

Fig. 6. Apparatus for illustrating the formation of water by the
combustion of hydrogen gas.

Fig. 7. Apparatus for producing harmonic sounds by the combustion
of hydrogen gas.]

CAROLINE.

It does not appear to me that you approach the wires so near as you did
when you made the battery act by itself.

MRS. B.

Water being a better conductor of electricity than air, the two wires
will act on each other at a greater distance in the former than in the
latter.

EMILY.

Now the electrical effect appears: I see small bubbles of air emitted
from each wire.

MRS. B.

Each wire decomposes the water, the positive by combining with its
oxygen which is negative, the negative by combining with its hydrogen
which is positive.

CAROLINE.

That is wonderfully curious! But what are the small bubbles of air?

MRS. B.

Those that appear to proceed from the positive wire, are the result of
the decomposition of the water by that wire. That is to say, the
positive electricity having combined with some of the oxygen of the
water, the particles of hydrogen which were combined with that portion
of oxygen are set at liberty, and appear in the form of small bubbles of
gas or air.

EMILY.

And I suppose the negative fluid h