One of the commonest of common natural objects is =water=; everybody
uses it in one way or another every day; and consequently everybody
possesses a store of loose information—of common knowledge—about it.
But, in all probability, a great deal of this knowledge has never been
attended to by its possessor; and certainly, those who have never tried
to learn how much may be known about water, will be ignorant of a great
many of its powers and properties and of the laws of nature which it
illustrates; and consequently will be unable to account for many things
of which the explanation is very easy. So we may as well make a
beginning of science by studying water.