t give to gold its value?

Would all the gold mined in the United States pay the national debt at
the end of the Civil War?

What causes have led to the increasing price of copper during the past
few years?

What is the market price each of copper, silver, steel rails, and
aluminium to-day?

FOR STUDY AND REFERENCE

Obtain specimens of the following iron ores: Hematite, brown hematite,
magnetite, carbonate, and pyrites. Note the color and physical
appearance of each; scratch the first four with a very hard steel point
and note the color of the streak.

Obtain specimens of pig-iron, cast iron, wrought iron, and cast steel;
note carefully the fracture or "break" of each; how does cast iron
differ from wrought iron?

Obtain specimens of the following copper ores: Malachite, azurite,
chalcopyrite, and red oxide; wet a very small fragment with an acid and
note the color when it is held in the flame of an alcohol lamp or a
Bunsen burner; dissolve a crystal of blue vitriol (copper sulphate) in
water and note what occurs if the end of a bright iron wire be dipped in
the solution.

Name the various uses to which nickel, tin, lead, and aluminium are put.

Consult the chapters on these subjects in any cyclopaedia.

[Illustration: TRANSPORTING SUGAR-CANE, CUBA]

[Illustration: SUGAR-CANE GROWING IN CUBA]

[Illustration: HAVEMEYER SUGAR-REFINERY, BROOKLYN, N.Y.]

CHAPTER XIV

SUGAR AND ITS COMMERCE

The term sugar is applied rather loosely to a large number of substances
characterized by the quality of sweetness. In a few instances the name
is given to certain mineral salts, such as sugar of lead, but in the
main the sugars are plant products very similar in chemical structure to
the starches. They are very closely connected with plant growth, and
even in animal life, starchy substances are changed to sugar in the
process of digestion. Although sugar does not sustain life, it is
necessary as an adjunct to other food-stuffs, and it is probably
consumed by a greater number of people than any other food-stuffs except
starch and water.

Three kinds of sugar are found in commerce, namely--_cane_-sugar,
_grape_-sugar, and _milk_-sugar. Cane-sugar occurs in the sap of the
sugar-cane, sorghum-cane, certain of the palms, and the juice of the
beet. Grape-sugar is the sweet principle of most fruits and of honey.
Sugar of milk occurs in milk, and in several kinds of nuts.

=Sugar-Cane Sugar.=--Cane-sugar is so c