The Manitowoc pilot. [volume] (Manitowoc, Wis.) 1859-1932, 1884-12-11
Nlonltorpof pilot.
THURSDAY, DECEMBER II, 1884.
Interesting Facts About Air.

There is always a wind at the burn
ing of a building, because the heated
air rises, and the cold air rushes in to
take its place.
Sound depends on the presence of
air, because the air is put into motion
by the action of the body producing
sound, in the same way as pool of
water is distributed by throwing in q
stone. The vibrations of the air gradu-
ally extend themselves until they reach
the ear, and communicate the idea of
sound to the mind.
This is easily illustrated by cIasping
a small bell with the hand, so as to
stop the vibration, when the sound will
instantly cease; or if bell be placed
under an air pump, as the air is gradu-
ally exhausted, the sound will grow
fainter, and finally cease altogether.
All solid bodies conduct sound more
readily than the air, and generally
their conducting power is in proper
ton to their density, iron conducting
ten and half-times better than the
air.
Smooth, calm water is very good
conductor, and even the earth conducts
sound much better than the atmos-
phere. Hence, the Indians. by LAYING
their heads on the ground, will discov-
er the approach of game, or the march
of body of men, when others in the
same situation would hear nothing
But it is its agency in respiration
which renders the study of the air
most important. In ordinary cases
lungs are filled with air about twenty
times in a minute, from ten or fifteen
cubic inches being inspired each time,
according to the size of the individual.
Thus every full-grown person re-
quires from twenty-five to thirty hogs
heads of air daily, or more than one
hogshead an hour. Not only is this
amount withdrawn from the atmos-
phere, but an equal quantity of an i'm
pure and poisonous gas is returned in
its stead.
So there is double source of con-
Elimination, TO say nothing of the large
amount of matter thrown off by the
skin.
The air thus received into the lun gs
is brought into contact with the whole
mass Of the blood by a continuance so
wonderful as to merit more particular
description,
If the assertion that 1.-THE undevout
astronomer is mad" be true, much
more must an undevout anatomist be
liable to the same accusation; for in
nothing is the wisdom and skill of the
Deity more manifest than in the
structure of the human frame.
The lungs consist of a light porous
substance, penetrated in every part by
minute cells, separated from each other
by membrane of so peculiar struct-
ure, that the air readily passes through
il. while the blood is retained.
These cells are so exceedingly minute
that a cubic inch contains 1000, 900 of
then, and the whole lungs about $780,
WO, 900, with a superficial surface of
20. coo square inches, or nearly 40
square feet, and all wrapped Up in a
mass not more than ten inches IN
length and five or six inches in dl-
ameter.
These cells are divided into layers.
so arranged that the cells of one layer
are filled with air. while those of the
layer next adjoining are occupied with
blood, the two sets being separated by
membrane so porous that while the
blood is retained, the air can readily
pass through it.
BY this means, the whole mass of the
blood is brought periodically in contact
with the air. The oxygen. amounting
to one-ffth of the whole, combines
with the carbon of the blood and is
expelled from the lungs in the form of
carbonic acid while the nitrogen is re-
turned in a pure state.-Ecery Other
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