of
salt, clear and glassy. The little rain that falls there melted the
blocks only enough to unite them firmly together; and there the house
has stood for many years.

Countries that have no deposits of rock salt can easily get plenty of
salt from the water of the ocean if they only have a seacoast. About
one thirtieth of the ocean water is salt, and if the water is
evaporated, the salt can be collected without difficulty. France makes
a great deal of salt in this way. When a man goes into the
manufacture, or rather, the collecting of salt, he first of all buys
or rents a piece of land,--perhaps several acres of it,--that lies
just above high water, and makes it as level as possible. Unless it is
very firm land, he covers it with clay, so that the water will not
soak through it. Then he divides it into large square basins, making
each a little lower than the one before it. Close beside the highest
basin he makes a reservoir which at high tide receives water from the
ocean. This flows slowly from the reservoir through one basin after
another, becoming more and more salt as the water evaporates. At
length the water is gone, and the salt remains. The workmen take
wooden scrapers and push the salt toward the walls of the basins and
then shovel it up on the dikes and heap it into creamy cones that
sparkle in the sunshine. The dikes are narrow, raised pathways beside
the basins and between them. As you walk along on top of them, you can
smell a faint violet perfume from the salt. Thatch is put over the
cones to protect them from the rain, and there they stand till some of
the impurities drain away. This salt is not perfectly white, because
the workmen cannot help scraping up a little of the gray or reddish
clay with it. Most of it is sold as it is, nevertheless, for many
people have an absurd notion that the darker it is the purer it is.
For those who wish to buy white salt it is sent to a refinery to be
washed with pure water, then boiled down and dried.

So it is that the sun helps to manufacture salt. In some of the colder
countries, frost does the same work, but in a very different manner.
When salt water freezes, the _water_ freezes, but the salt does not,
and a piece of salt water ice is almost as pure as that made of fresh
water. Of course, after part of the water in a basin of salt water has
been frozen out, what is left is more salt than it was at first, and
after the freezing has been repeated several times, only