lled, helps them to grow sometimes quite as good crops as if they had
learned agricultural chemistry.

What he meant by the chalk sweetening the land you would not understand
yet, and I can hardly tell you; for chemists are not yet agreed how it
happens. But he was right; and right, too, what he told you about the
water inside the chalk, which is more important to us just now; for, if
we follow it out, we shall surely come to a cave at last.

So now for the water in the chalk. You can see now why the chalk-downs
at Winchester are always green, even in the hottest summer: because Madam
How has put under them her great chalk sponge. The winter rains soak
into it; and the summer heat draws that rain out of it again as invisible
steam, coming up from below, to keep the roots of the turf cool and moist
under the blazing sun.

You love that short turf well. You love to run and race over the Downs
with your butterfly-net and hunt "chalk-hill blues," and "marbled
whites," and "spotted burnets," till you are hot and tired; and then to
sit down and look at the quiet little old city below, with the long
cathedral roof, and the tower of St. Cross, and the gray old walls and
buildings shrouded by noble trees, all embosomed among the soft rounded
lines of the chalk-hills; and then you begin to feel very thirsty, and
cry, "Oh, if there were but springs and brooks in the Downs, as there are
at home!" But all the hollows are as dry as the hill tops. There is not
a brook, or the mark of a watercourse, in one of them. You are like the
Ancient Mariner in the poem, with

"Water, water, every where,
Nor any drop to drink."

To get that you must go down and down, hundreds of feet, to the green
meadows through which silver Itchen glides toward the sea. There you
stand upon the bridge, and watch the trout in water so crystal-clear that
you see every weed and pebble as if you looked through air. If ever
there was pure water, you think, that is pure. Is it so? Drink some.
Wash your hands in it and try--You feel that the water is rough, hard (as
they call it), quite different from the water at home, which feels as
soft as velvet. What makes it so hard?

Because it is full of invisible chalk. In every gallon of that water
there are, perhaps, fifteen grains of solid chalk, which was once inside
the heart of the hills above. Day and night, year after year, the chalk
goes down to the sea; and if there were such creatures as