The Red Cloud chief., 1881-05-19
Air and Water.


The two substances everywhere met
with on the surface of this globe which
receive the least popular attention are
air and water. The latter especially is
one Of the most remarkable substances
in nature. and exceeds in is p~ervasive-
ness ever the air. Go where we vii.
on the most arid desert. the monntain
top. the frozen pole, in the deep-s.
cavern. We meet with water in some "
al of is forms. The coolest, hottest.
or driest air found in nature contains
aqueous yapor. Water forms a large
portion o; many minerals. in which bv
the giant power of chemical affinity IL
is directly combined or Is locked up IS
water of crys~tallizatIon. To adequate
IL discuss all the natural pAen1mena IN
which some form Of water II a factor
would require a volume; ~ enumerste
and describe all lis industrial applica-
tons would require a number of
volumes.
Both air and water arr essential TO
the existence of all known life. Our
bodily health can only be supported BY
our taking quantities of both At short
intervals. Both may and often do be-
come the vehicles of deadly pOisons.
which in densely populated countries
and towns are liable 20 coniamina,e
them. 1t is Of essential Importance
that supplies of each needed for the sup
port Of animal life should be pure.
Air and water are the great natural
distributors OF heat and cold. The
climates OF different parts OF the world
are very materially affected By the hoG
or cold currents of air which flow over
them. and by the analogous currents OF
water established by the action Of heat
in the great seas. Proximity TO large
bodies of water also has a very import
ant effect upon climate. Water slowly
atsorbs the summer heat IN very large
quantity. and slowly gives il on again
to the colder air of winter. thus temper
ing what would otherwise be cold and
freezing winds. and rerarding frost
Air and water are the great natural
distributors of mechanical energy. The
currents of rivers represent n portion
of the mechanical equivalent OF solar
heat expended in raising the masses Of
water that low through their channels
to the clouds. The winds that propel
our ships and wind motors are the prod
uet If solar energy also. The chief
and most economical means b. which
the heat generated in the combustion
of fuel can he converted into mechan-
zeal energy for the propulsion of ma
chinery is water. which this heat con
verts into steam.
The envelope of aqueous ID which
surrounds the globe. and forms a nota-
BILE part OF its atmosphere. is, as has
been well shown by Tyndall, the great
conservator Of terrestrial heat. Should
this aqueous envelope he removed BY
any cause the heat of the carth's sur
face would sc rapidly radiate into
space that every living thing would
shortly perish.
The ice cover which forms upon the
surfaces OF lakes and rivers protects the
life which exists in such waters. Were
it no. for this provision of nature these
water deposits would become solid
masses. is which all their teeming life
would be immovably imprisoned.
The snow blankets which have spread
this year over a large portion of our
land perform a similar service for the
vegetable life which lies dormant be-
low. Without this protection the
ground would be too deeply frozen,
the frost would be too late in leaving
the earth in the spring, the growing
season would be shortened, aud many
of the plants that nov thrive in the
temperate zones would cease To exist in
ATTITUDES where they now abound.
Air and water vapor are h great
difuserS of light. Were it not for our
atmosphere no solar light could pene-
tratc our houses where the suns RAYS
do not directly enter. except such as
might be reflected from solid objects.
Everything not directly illuminated by
the sun would lie in deep shadow. In
the midday many of our apartments
would require artificial illumination.
Out of the direct sunshine only the Low
est forms of life could exist. But the
enormous diifusing. transmitting and
rejecting power of our atmosphere
cOmrensates almost wholly for disad-
yantages of position, causing light TO
penetrate almost rs universally rs the
air itself.
Thus is illustrated the wonderful
character OF these common substances
air and water-so important TO al
animated existence, yet so heedlessly
regarded by the mass Of mankind
Scientific .American.