The Providence news. (Providence [R.I.]) 1891-1906, 1899-04-21
DUST AND ITS VALUE.
The fertility Of ihs Soil largeb Due 10 I, Pro-
tessor Wey Says.

"If IL wasn't for dust" said Professor
Wiley. tho chief chemist OF the Agri-
cultural Department at Washington,
man would have TO devise new plan
OF existence: he would be compelled to
provide himself with food by some
other means than agriculture You
could not have a farm or garden
without dust. II would not be possible
for "A crop To grow unless the soil con-
tanned an organism capable OF convert
ing nitroeenOus matter into nitric acld.
Nitrogen is indispensable as plant food.
and plants can assimllate only when
presented I'm the form Of nitro acid,
commonly known as aqua-fortis.That is
incapable of auto-lOcomotion, ana can
DE distributed only through the dust
which falls upon the soil and upon the
leaves Of trees and riants.. ffrf't-es dust
is essential to the pursuit Of agriculture
and If it wasn't being carried obout
constantly or the breeZes of the air,
we would simply have TO quit farming
animals would have nothing to feed up
on. and We would have neither meat
nor bread nor vegetables.
II have been spending some years
continued Professor Wiley. 'in the In
yestigation of the agricultural value of
dust, and IL Is a very important subject.
The soil is continually being revived
and enriched from the particles that
are floating about i'm the atmosphere.
They came from two scources; first,
atoms of the earth's surface caught up
by the wind and distributed elsewhere,
and. second. what we call cosmic dust
that Is, mineral matter of meteoric or
igin.
I'VE are getting gradually TO under
stand its quantity, it's value and the
important part " plays in agriculture.
The heavenly bodies are constantly
shedding fragments OF iron and other
mineral substances which fall with
great velocity, and when they reach the
atmosphere that surrounds the earth
are heated by friction and catch fire
by contact with the oxygen. They are
then burned toHashes and scattered in
minute and invisible atoms. Some of the
larger pieces that become detached
from the stars reach the earth without
being entirely consumed. We call them
meteors. but the little particles that
permeate the air, because of this per-
petual and violent bombardment from
the stars, are composed OF phosphoric
acid. potash and other chemicals, which
are absolutely essential i'm renewing the
fertility OF the soil.
What we c.sl terrestrial dust is al
so of great Importance To agriculture.
trely composed of particles that have
been left there by the winds. This is
particularly true OF soils that are made
up OF volcanic ashes. which are carrie l
immense distances from the craters. \
considerable percentage of the soil
on the earth's surface was orig
inally volcanic dust. which has been
distributed by that good friend of man
we call the wind. Pompeii and Her
culaneum illustrate the great depth to
which volcanic dust may reach. These
are called Aeolian soils.
"The dust from the streets of cities Is
OF a composite nature and carries all
sorts of fragments and atoms in Vari-
Gus sorts of decay. 1t has a high de
gree of agricultural significance, be
cause IL Is loaded with germs Of all
kinds. Some of them are very useful
and some are injurious. The effect up
on the public health is not injurious eX-
cept where the dust carries pathogenic
germs-that is. the germs Of disease.
AS ban Illustration. the sputum OF a con-
sumptive, If elected on the sidewalk. Is
reduced 10 dust when IL dries. and ls
then distributed throught the air i'm the
form OF germs. II they find lodgment
I'm the lungs OF a human being whose
physical condition allows them 10 re-
vive and grow. tho disease gets a foot
hold and can be conveyed from one 10
another