The reason why : $b a careful collection of many hundreds of reasons for things which, though generally believed, are imperfectly understood. A book of condensed scientific knowledge for the million — John Stuart Mill — John Shaqi
The reason why : $b a careful collection of many hundreds of reasons for things which, though generally believed, are imperfectly understood. A book of condensed scientific knowledge for the million
John Stuart Mill · en
Knowledge of _Electricity_ enables man to stand in comparative safety
amid the awful war of the elements. Lightning, the offspring of
electricity, has a tendency to strike upon lofty objects by which
it may be attracted. By its mighty powers churches or houses may be
instantly levelled with the dust. But man, knowing that electricity
is strongly attracted by particular substances, raises over lofty
buildings rods of steel communicating with bars that descend into the
ground. The lightning, rushing with indescribable force toward the
steeple, is attracted by the bar of steel, and conducted harmlessly to
the earth. Man may thus be said to take even lightning by the hand,
and to divert its destroying force by the aid of Knowledge. And in
countless other instances "Knowledge is Power."
CHAPTER II.
4. _Why do we breathe air?_
Because the air contains _oxygen_, which is necessary to life.
5. _Why is oxygen necessary to life?_
Because it combines with the _carbon_ of the blood, and forms _carbonic
acid gas_.
[Verse: "Be not as the horse, or as the mule, which have
no understanding: whose mouth must be held with the bit and
bridle."--PSALM XXXII.]
6. _Why is this combination necessary?_
Because we are so created that the substances of our bodies are
constantly undergoing change, and this resolving of solid matter into a
gaseous form, is the plan appointed by our Creator to remove the matter
called _carbon_ from our systems.
7. _Why do our bodies feel warm?_
Because, in the union of _oxygen_ and _carbon_, heat is developed.
8. _What is this union of oxygen and carbon called?_
It is called _combustion_, which, in chemistry, means the decomposition
of substances, and the formation of new combinations, accompanied by
heat; and sometimes by light, as well as heat.
9. _What is formed by the union of oxygen and carbon?_
Carbonic acid gas.
10. _What becomes of this carbonic acid gas?_
It is sent out of our bodies by the compressure of the lungs, and
mingles with the air that surrounds us.
11. _Is this carbonic acid gas heavier or lighter than the air?_
Pure carbonic acid gas is the heaviest of all the gases. That which is
sent out of the lungs is not pure, because the whole of the air taken
into the lungs at the previous inspiration has not been deprived of its
_oxygen_, and the nitrogen is returned. Therefore the breath sent out
of the lungs may be said to consist of _air_, with a large proportion
of _carbonic acid gas_.
12. _What is the composition of air in its natural state?_
It consists of _oxygen_, _nitrogen_, and _carbonic acid gas_, in the
proportions of oxygen 20 volumes, nitrogen 79 volumes, and carbonic
acid gas 1 volume. It also contains a slight trace of watery vapour.
13. _What is the state of the air after it has once been breathed?_