gently and swiftly forty miles, to where the railroads can take it
everywhere. It goes so easily! There is no railroad to build, no car
to haul back, only to stand still and see gravitation do the work.

How do they get the salt and water apart? O, just as easily. They ask
the wind to help them. They cut brush about four feet long, and pile
it up twenty feet high and as long as they please. Then a pipe with
holes in it is laid along the top, the water trickles down all over the
loose brush, and the thirsty wind blows through and drinks out most of
the water. They might let on the water so slowly that all of it would
be drunk out by the wind, leaving the solid salt on the bushes. But
they do not want it there. So they turn on so much water that the
thirsty wind can drink only the most of it, and the rest drops down
into great pans, needing only a little evaporation by boiling to become
beautiful salt again, white as the snows of December.

There are other minerals besides salt in the beds in the mountains,
and, being soluble in water, they also come down the tiny railroad with
musical laughter. How can we separate them, so that the salt shall be
pure for our tables?

The other minerals are less avaricious of water than salt, so they are
precipitated, or become solid, sooner than salt does. Hence with nice
care the other minerals can be left solid on the bushes, while the salt
brine falls off. Afterward pure water can be turned on and these other
minerals can be washed off in a solution of their own. No fairies
could work better than those of solution and crystallization.