ed with them, they sank
to the bottom, and being buried in the lower soil of adjacent lands,
became transformed into a new state among the members of the mineral
kingdom. A long interment followed, during which a course of chemical
changes, and new combinations of their vegetable elements, converted
them to the mineral condition of coal.

_Primeval_, original, existing before the flood.

_Gigantic_, extremely large, greater than the usual size.

_Interment_, burial under the ground.

_Elements_, the several parts or principles of which bodies
are composed.

What is a Coal Mine?

A subterraneous excavation, from which coal is obtained.

Do the terms Coal and Charcoal signify the same substance?

No; Charcoal is an artificial fuel, made in imitation of coal, by
burning wood covered with earth so as partially to exclude the air. It
is used for various purposes, as the making of gunpowder,[7] polishing
brass and copper, &c., and when a clear and bright fire is required,
as it burns with little or no smoke; it is dangerous, however, for one
to remain many hours in a close room with a charcoal fire, as the
fumes it throws out are hurtful, and would destroy life. Charcoal, in
fact, is the coaly residuum of any vegetables burnt in close vessels;
but the common charcoal is that prepared from wood, and is generally
black, very brittle, light, and destitute of taste or smell. It is a
powerful antiseptic, unalterable and indestructible.

[Footnote 7: See Chapter XII.]

_Residuum_, the remaining part, that which is left.

_Antiseptic_, that which prevents putrefaction.

What is Iron?

One of the most useful and abundant metals; being found in all mineral
earths, and stones; in plants, and animal fluids; and is the chief
cause of the varieties of color in all. Iron is found in great masses,
in various states, in the bowels of the earth; it is usually, however,
compounded with stone, from which it is separated by the action of
fire. In some parts of the world, whole mountains are formed of iron;
among these may be mentioned the Pilot Knob and the Iron Mountain, in
Missouri, being unsurpassed by anything of the kind found elsewhere.

What are its characteristics?

It is hard, fusible, not very malleable, but extremely ductile, and
very tenacious; it is of a greyish color, and nearly eight times
heavier than water. Without iron, society could make no progress in
the cultivati