Elmore bulletin. [volume] (Rocky Bar, Idaho) 1889-1906, 1897-09-22
MINING MATTERS.
FINDING GOLD WITH x-RAYs.
They Also Reveal the Presence of silvss
Copper and Lead.

xhey Also Reveal the Presence of silvss
Copper and Lead.
Making assays Of ore supposed 10
contain precious metals by means OF
the x ray is the latest phase of tho
development of the wonderful devics
discovered by Professor Roentgen. Not
only has this been demonstrated to be
possible, but is Is also practical,
which Is of a great deal more import
ance. This discovery opens tie
@ay to rich gold finds in places where
gold would not, under ordinary cir
eumstances be supposed to exist.
DIR. ID. n. Hennessey of Napa. Califor-
mia, who Is we'll known as a scientific
investigator, Is the discoverer of the
unique scheme just referred to. He has
been at work on it for a long time
and all who make scientific research
es must but he Is now ready to give
the results of his discoveries to the
world, that all may profit by them.
DR.. Hennessey makes no attempt to
keep his methods secret, but is willing
that they be utilized where they do
the most good.
Gold quartz was the rock with
which he first had any success. In
making his experiments he pivoted In
his results. At one time he would be
successful, and at another he would
be very far off. Different exposures
seemed to have very little to do with
u, for with the same piece of ore on
the same kind of plates the results
varied to the widest degree. The doc
tor then began making records of the
exact condition of his tube during the
different experiments. 1t so happened
In 10 ,I,n,n h
tube was very "low' and was surpris-
ed to get good Indication of ore In
a piece OF quartz. A little longer ex-
posure and the result was better. And
so 1t went on until the proper time OF
exposure was found. He had demon
strate6 tnat low tube, or one that
does not produce many X-rays was
the best for the purpose. 1t has long
been known that tube of this kind
always give the strongest contrasts,
but 1t is undesirable for surgical work
on account of the time required to
make the exposure. In making assays
this Is, of course, a matter of no I'm.
portance.
Why the low tube should produce
better results than the high tube Is
easily understood by anybody acquaint-
ed with photography. A dim light in
a room will make stronger shadows
In photograph than strong one in
a given length of time. In the case
OF the X-ray, the high tube creates a
radiance that has a tendency to pass
through everything, and so 1t happens
that by the time a certain part of the
plate is exposed enough the other
parts are over-exposed, and conse-
quently show no contrast. The results
! lN 1a1. f1,A thA LAT
had been logged.
After DR.. Hennessey had reached per-
fection In making X-ray pictures of
gold ore he tried different kinds of
other ore, and the results were most
surprising. The difference between
gold and silver is of the widest de-
scription, and copper and lead are very
different from either. Gold looks like
frost markings on a window pane
while silver looks like tiny specks,
Different ores in the same piece of rock
are all plainly distingulshable. And
not only does the X-ray show that
there Is gold in certain rock, but 1t
also approXimates how much of the
metal there is. DR. Hennessey has
tested this, and found that it Is quite
reliable. Certainly enough to tell
whether the ore Is worth making a
series OF tests or.
The most surprising discovery made
by DR.. Hennessey, though, is the fact
that the X-ray will show gold In rock
that has no outward sign of its exist
ence. Several pieces found in the Napa
hills, of such character that no miner
would look at them for more than a
moment before throwing them aside
as worthless, under the X-ray proved
to contain layer of thin gold; small
in quantity, but nevertheless gold. The
accompanying drawings show the out
side views of bits of quartz. Many OF
the pieces of quartz examined did moi
show any signs Of gold on the outside
even when put under a strong magni
flying glass.
, OF course the great advantage of the
X-ray In assaylng is its cheapness. Ex
aminations of thirty small pieces car
be made on one plate at cast of aboui
, 81 at the most. The same work done
) In the usual manner would cost a.
least $50. 1t will now be an easy mat
ter for miners to take a number o.
: specimens, cave them put through th,
d X-ray process and determine whethe,
d they contain gold or not. Oftentime
miners will throw away good specl
: mems because there are no outward In
4 dications of gold. To get these piece
?, tested at 81 apiece Is more than mos
3 miners can afford. The time has nov
come when the work can most easil,
3 be done by X-ray operators for abou
r 10 cents apiece In large lots. Th
e really means a revolution In prospect
n ing, and the ground of the state i
;, sure to be more thoroughly workes
than ever before.
le