100 THE FAIRY-LAND OF SCIENCE. 
and all this goes to the sea. Now, when the sun- 
waves come to take the water out of the sea again, 
they will have nothing but the pure water itself; and 
so all these salts and carbonates and other solid sub- 
stances are left behind, and we taste them in sea- 
water. 
Some day, when you are at the seaside, take some 
sea-water and set it over a fire till a great deal has sim- 
mered 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, of 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 skele- 
tons, 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 
