a gas-lamp in no point different from the water that you distil from the
river, or ocean, or spring, but exactly the same thing. Water is one
individual thing it never changes. We can add to it by careful
adjustment, for a little while, or we can take it apart, and get other
things from it; but water, as water, remains always the same, either in a
solid, liquid, or fluid state. Here, again [holding another bottle], is
some water produced by the combustion of an oil-lamp. A pint of oil, when
burnt fairly and properly, produces rather more than a pint of water.
Here, again, is some water, produced by a rather long experiment from a
wax candle. And so we can go on with almost all combustible substances,
and find that if they burn with a flame, as a candle, they produce water.
You may make these experiments yourselves. The head of a poker is a very
good thing to try with, and if it remains cold long enough over the
candle, you may get water condensed in drops on it; or a spoon or ladle,
or anything else may be used, provided it be clean, and can carry off the
heat, and so condense the water.
And now to go into the history of this wonderful production of water from
combustibles, and by combustion I must first of all tell you that this
water may exist in different conditions; and although you may now be
acquainted with all its forms, they still require us to give a little
attention to them for the present, so that we may perceive how the water,
whilst it goes through its Protean changes, is entirely and absolutely the
same thing, whether it is produced from a candle, by combustion, or from
the rivers or ocean.
First of all, water, when at the coldest, is ice. Now, we philosophers I
hope that I may class you and myself together in this case speak of water
as water, whether it be in its solid, or liquid, or gaseous state, we
speak of it chemically as water. Water is a thing compounded of two
substances, one of which we have derived from the candle, and the other we
shall find elsewhere. Water may occur as ice; and you have had most
excellent opportunities lately of seeing this. Ice changes back into
water for we had on our last Sabbath a strong instance of this change, by
the sad catastrophe which occurred in our own house, as well as in the
houses of many of our friends, ice changes back into water when the
temperature is raised: water also changes into steam when it is warmed
enough. The water which we have here before us is in its densest
state[11], and although it changes in weight, in condition, in form, and
in many other qualities, it still is water; and whether we alter it into
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