The Anderson intelligencer. [volume] (Anderson Court House, S.C.) 1860-1914, 1900-05-09
The Uses OF Dust.

| 1AACCCut lutCESStIuS HOIuut, WuCTCIu
a prominent scientist recounts the
achievements Of this wonderful GEN.
tury, contains an entire chapter de-
voted to the discovery of "The I'M
portance of Dust-A source Of beauty
and an essential to life." The
chapter reads like fairy tale, and
leads one to exclaim with Addison,
"The hand that made US divine!"
To be sure, dust is very often a
great nuisance, as we'll as source Of
danger and disease; and much effort
Of man in enlightened countries has
been directed toward abolishing dust.
Science tells US, however, that we are
dependent upon dust for much Of the
beauty, perhaps even the habitability
of the earth.
Why arc the sky and the deep ocean
so blue? Once the scientist was con-
tent to say that this was the natural
color of great quantities of air and
water. The late Professor Tyndall,
however, performed an experiment
that led to another answer. Every
body has seen the floating dust in q
sunbeam in partially darkened ROOM
but it was not known that if there
were no dust in the air the path Of
the sunbeam would be totally black
and invisible, while if only very
little dust were present in very minute
particles it would be as blue as sum-
mer sky. Professor Tyndall proved
this By a simple experiment. He
passed ray of electric light through
a long glass cylinder. First the cyl
inder was filed with the ordinary air
of the room and was brilliantly illumi-
mated by the electric ray. Next the
cylinder was exhausted and filled with
air which had been passed through a
fine gs..e &C intensely heated plati-
mum wire, so as to burn up all ,Lc
floating dust particles; the electric
light failed to illuminate the cylinder,
which appeared as if filled with q
densely black cloud.
Next the experimenter passed air
into the cylinder through the gauze,
but SO rapidly as not to consume all
the dust PARTICLES; whereupon slight
blue blaze appeared, which became
more and more distinct as the dust
filed air increased. The explanation,
in the scientists words, is as follows:
"When all the larger dust PARTICLES
are wholly or partially burnt, 80 that
only the very smallest. fragments re-
main, blue light appears, because
these are so minute as to reflect
chiefly the more refrangible rays,
which are Of shorter wave-length-
those at the blue end Of the spectrum,
which are thus scattered in all direc-
tions, while the red and yellow rays
pass straight on as before"
High up in the atmosphere the par
ticles Of dust are necessarily smaller,
since the rare atmosphere will support
only light weights. Hence the tint
we call ''sky blue" Going up to the
top Of high mountain or ascending
in balloon, the sky looks even
deeper blue, because at these great
heights the observer escapes or yellow
light from the coarser dust of the
lower atmosphere.
Many poets have sung Of the blue
"1talian skies" but it has been left
for the scientist to tell us Why their
blue is 30 rich and deep. Italy being
situated between the Mediterranean
Sea on the one side and the snowy
Alps on the other, the lower strata Of
air have less quantity or atmospheric
dust, hence the upper strata suffer
less dilution by reflection. The bluest
Of all skies is that Of the Central
Pacific Ocean, where, owing to the
small area Of land, the lower atmos-
naere is more free from coarse dust
than in my other part Of the world.
All this unsurpassable glory of the
SUNSETS says the sober scientist:
we owe to-dust!' Tho same prin-
ciple is believed to explain the blue
color Of the deep seas. But the
scientist goes further and tells US that
it is even doubtful whether VIC could
live 10 the earth without dust.
Made Of the dust Of the earth, VIC
aro>still beholden it. To the pres
ence Of dust in tho higher atmosphere
we owo the formation Of mists, clouds,
and gentle, beneficial rains, instead Of
waterspouts and destructive torrents.
It has been proved by experiment