The Princeton union., 1914-09-10
ORIGIN OF Nj / AIS.
Varied Theories as to How the
Ores Are Formed.
NATURE HIDES THE SECRET

Science Has For Centuries Tried to
Wrest It From Her, but Biologists
and Mineralogists Are as Vet Unable
to Agree Upon the Process.
You have read of that legendary In
dian who while chasing game on a
Bolivian mountain side seized Il bush
to prevent himself from falling, and.
the bush being pulled loose from its
scanty hold on the rocks. he saw it's
crooked roots grasping masses of
cleaning white ore and thus became
the discoverer of the famous silver
mines Of Potosi.
You have also read, perhaps with
itching fingers, Of prospectors picking
up nuggets Of gold worth a thousand
dollars each or opening veins of quartz
all shot through with heavy threads
Of the yellow metal.
You know that ores Of gold and
silver or of any other precious or use
full metal are not to be found in every
body's back yard, but must be sought
for in certain favored parts of the
earth.
But has your intelligent curiosity ever
led you to inquire how those ores came
to be where they are and nowhere
else? Have you ever wondered what
makes gold nugget:
Possibly you think that gold and
other metals grow somewhat as fruits
do-in soils and climates that are spe-
cially suited to them. Well, there is
considerable truth in that idea, and
the word "grow" is, in one sense, sur
prisingly applicable to such deposits.
But there is great deal more in the
matter than you would imagine, and
on no subject has science fought more
battles royal than on this Of the origin
Of metallic ores. I think that there are
some geologists who would rather find
ont this secret to the very bottom than
discover the richest lode that the ribs
of the earth contain. II they could do
both that would be perfection, and we
must not forget that knowledge is
power.
Until about 400 years ago everybody
who thought about it at all believed
that veins of precious ore were dis
tributed under the influence of the
planets. At that time astrology held
the place Of science
Finally George Agricola, a German
mineralogist, who lived about the time
w thn
and Peru were making Spain the tenn
porary mistress Of the world, hit upon
a theory which came in substance very
near the truth. He taught that water.
penetrating into the earth and becom-
ing heated, took up scattered minerals
In solution and afterward deposited
them as ores in cavities in the rocks.
The mineral solutions he called the
earth's '.juices."
A couple Of hundred years later the
German geologist Werner set forth
view that became very famous under
the name Of the ''Neptunist theory"
from Neptune. the god OF the sea.
Werner's idea was that as the earth
cooled down from the primevaI nebula
out of which it was formed it was en-
veloped in universal hot ocean, hold
ing in solution all kinds of minerals,
and that when the rocky crust was
formed the water leaking down into
it deposited its metallic contents by
chemical precipitation in veins and
lodes wherever the circumstances were
favorable.
But a hundred years ago the Nep-
tunlst theory, which had swept every
thing before it in the minds of men
OF science, met its Waterloo at the
hands Of Hutton, the Scottish geolo-
g1sr, with his ''Plutonic" theory (from
Pluto, the god of the Internal regions).
Hutton's idea was that the materials
which fill the metallic veins were melt
ed by heat and forcibly injected into
the clefts and assures Of the strata
from below.
The 'Neptunists'' and ''Plutonists"
had a hard fight, with the latter hold
ing the upper hand, until their theory
had assumed a kind of compromise
form, with water again playing the
principal role. The American geolo-
gist, Van Hise, is the author Of one of
the latest theories, according to which
meteoric water CONDENSED atmospheric
vapor) penetrates deep into the earth's
crust, and, with steadily increasing
temperature, takes up mineral matter
into solution. Spreading, as it gets
fha
ings in the rocky crust, in which it
ascends, with decreasing temperature
and pressure.
There it deposits the ores, whose ma
terials it has collected in its wander.