and so all these salts and carbonates and other solid substances
are left behind, and we taste them in sea-water.

Some day, when you are at the seaside, take some extra water and
set it on the hob till a great deal has simmered gently away, and
the liquid is very thick. Then take a drop of this liquid, and
examine it under a microscope. As it dries up gradually, you will
see a number of crystals forming, some square - and these will be
crystals of ordinary salt; some oblong - these will be crystals
of gypsum or alabaster; and others of various shapes. Then, when
you see how much matter from the land is contained in sea-water,
you will no longer wonder that the sea is salt; on the contrary,
you will ask, Why does it not grow salter every year?

The answer to this scarcely belongs to our history of a drop of
water, but I must just suggest it to you. In the sea are numbers
of soft-bodied animals, like the jelly animals which form the
coral, which require hard material for their shells or the solid
branches on which they live, and they are greedily watching for
these atoms of lime, of flint, or magnesia, and of other
substances brought down into the sea. It is with lime and magnesia
that the tiny chalk-builders form their beautiful shells, and the
coral animals their skeletons, while another class of builders use
the flint; and when these creatures die, their remains go to form
fresh land at the bottom of the sea; and so, though the earth is
being washed away by the rivers and springs it is being built up
again, out of the same materials, in the depths of the great
ocean.

And now we have reached the end of the travels of our drop of