bove them.
It becomes solid when cooled, but expands at the same time, so that it
is less dense when solid than when liquid--a most unusual proceeding!
And when heated it is converted into vapour, but with a loss or
"making latent" of heat, which, like its behaviour when solidifying,
indicates that water is endowed with a very peculiar structure or
mechanism in the putting together of its molecules. We might call
these combined peculiarities of water "aquosity," and as we certainly
cannot say why water should possess the lot of them, whilst other
compounds of either hydrogen or of oxygen, or, in fact, of any other
elements, do not possess this combination, we might say that their
presence is due to "the aqueous principle," or "aquosity," which
enters into water when it is formed, but does not exist in other
natural bodies, and, indeed, "sharply separates aqueous from
non-aqueous matter."

Happily, though such a view would have been considered high philosophy
200 years ago, no one is deluded at the present day into the belief
that by calling the remarkable properties of water "aquosity" you have
added anything to our knowledge of them. Yet those who invoke "a vital
principle" or "vitality" in connection with protoplasm should, if they
were consistent, apply their method to the mystery of water. Let us
see how it would run. Though we may (the "vitalists" or "aquosists"
would say) experiment with water, determine exactly the temperature
and pressure at which these remarkable phenomena are exhibited, though
we may determine its surface tension and its crystalline form, and
even though we may weigh exactly the proportion of hydrogen to oxygen
in its composition, yet when we look at a drop of water, there it is,
a wonder of wonders, endowed with "aquosity," the ultimate nature of
which is as inscrutable now as it was to Aristotle! It is perfectly
true (we concede to the "aquosists") that the properties of water are
not accounted for by science; that is to say that, though we can
imagine the molecular and atomic mechanism necessary for their
exhibition, we cannot offer any suggestion as to how it is that that
particular mechanism is present in the chemical compound which the
chemist denotes as H_{2}O, and is not present in other compounds,
still less can we say "why" these remarkable properties are
present--that is to say, for what purpose, although we know that if
they were not present the whole history and economy of our gl