side, and inside of a
deep yellow or orange, which changes to a pale bright yellow on being
moistened.

What are the uses of Gamboge?

Dissolved in water, it forms a beautiful and useful color for the
painter. It is also used in medicine. Gamboge is soluble in either
water or spirits of wine. Mixed with a blue color, it forms green, in
various shades according to the different proportions of the
ingredients.

What is Logwood?

The wood of a tree which grows in parts of America and the West
Indies. It is imported in great quantities, and employed in dyeing
purple and the finest blacks.

What is Tar?

A coarse, resinous liquor issuing from the wood and bark of pine or
fir-trees; it is in fact the oily juices of the sap thickened and
colored by the heat of the sun or by age; it is extracted for use by
burning the wood of the trees under a heavy covering of turf or earth;
the tar exudes during the slow combustion, and is collected into a
cavity dug in the ground for the purpose. Tar is exported in great
quantities from Norway, Sweden, and our Southern States.

What are its uses?

It is applied to the sides of ships and boats and their rigging, to
preserve them from the effects of the weather; it is used instead of
paint for palings, &c.; and sometimes also in medicine. A kind, called
_mineral_ tar, is also drawn from coal by the process of distillation.
Mineral tar is also found native in some parts of the earth.

What is Pitch?

A kind of juice or gum, likewise drawn from unctuous woods, chiefly
those of the pine and fir; it is used for nearly the same purposes as
tar in shipping, medicine, and various other arts. Pitch is properly a
juice of the wild pine, or pitch tree; it is of a glossy black color,
dry brittle, and less bitter and pungent than the liquid tar.

What is Camphor?

A vegetable substance, chiefly procured from a kind of laurel, (Laurus
Camphora,) growing in Borneo, Japan, and many East Indian islands; it
is also produced from other plants and shrubs, though in very small
quantities.

How, and from what part of the tree is it taken?

All parts of the tree are impregnated with camphor; but it is
principally extracted from the roots and trunk, by distillation; it is
white, and of a crystal form: its odor is extremely fragrant. In this
state it is called _rough_ camphor, and is thus exported. The Greeks
and Romans do not appear to have been acquainted with this valuable
drug;