pure alumina, and consists of the metal aluminum and the gas
oxygen. Cryolite is now melted by electricity. The white powder is put
into it, and dissolves just as sugar dissolves in water. The
electricity keeps on working, and now it separates the alumina into
its two parts. The aluminum is a little heavier than the melted
cryolite, and therefore it settles and may be drawn off at the bottom
of the melting-pot.

There are a good many reasons why aluminum is useful. As has been said
it is strong and light and does not rust in moisture. You can beat it
into sheets as thin as gold leaf, and you can draw it into the finest
wire. It is softer than silver, and it can be punched into almost any
form. It is the most accommodating of metals. You can hammer it in the
cold until it becomes as hard as soft iron. Then, if you need to have
it soft again, it will become so by melting. It takes a fine polish
and is not affected, as silver is, by the fumes which are thrown off
by burning coal; and so keeps its color when silver would turn black.
Salt water does not hurt it in the least, and few of the acids affect
it. Another good quality is that it conducts electricity excellently.
It is true that copper will do the same work with a smaller wire; but
the aluminum is much lighter and so cheap that the larger wire of
aluminum costs less than the smaller one of copper, and its use for
this purpose is on the increase. It conducts heat as well as silver.
If you put one spoon of aluminum, one of silver, and one that is
"plated" into a cup of hot water, the handles of the first two will
almost burn your fingers before the third is at all uncomfortable to
touch.

[Illustration: A "MOVIE" OF AN ALUMINUM FUNNEL

_Courtesy The Aluminum Cooking Utensil Company._

Seventeen other operations are necessary after the thirteenth stamping
operation before the funnel is ready to be sold. And after all this
work, we can buy it for 35 cents at any hardware store.]

Aluminum is found not only in clay and indeed in most rocks except
sandstone and limestone, but also in several of the precious stones,
in the yellow topaz, the blue sapphire and lapis-lazuli, and the red
garnet and ruby. It might look down upon some of its metallic
relatives, but it is friendly with them all, and perfectly willing to
form alloys with most of them. A single ounce of it put into a ton of
steel as the latter is being poured out will drive away the gases
which often make lit