The Wallace miner. [volume] (Wallace, Idaho) 1907-current, 1914-03-19
SIMPLE WAY TO TEST
RAD|UM BEARING ORE
PHOTOGRAPHIC PLATE. WILL RE.
CORD MOST MINUTE PAR.
TiCLE IN ORE.

A Big creek prospector has found
substance which he believes is pitch
blende and which is therefore sus-
pected of carrying radium. In order
to satisfy his curiosity he has sent a
sample to Denver for analysis. He
might have saved time and expense
by calling to his aid photographer.
or If he CHANGED to be an amateur
photographer he might have solved
the question himself in a manner re-
commended by the United States bur-
eau of mines:
A Simple Process.
Take a Photographic plate and wrap
1t in two thicknesses Of black paper.
This. Of course is to be done In a
dark room. On top Of the wrapped up
plate lay key, or coin, or any me-
tallic object possessing characteris-
tic outline--the key is usually en-
ployed Then suspend directly over
the key specimen Of the suspected
rock or ore, weighing at least two or
three ounces. Do not let it press up
on the key or the plate.
Finally put the entire apparatus in
side a light-tig box. OF course, the
whole proceeding must take place in
the dark room, with no more illumin-
alton than that furnished by photo
grapher's red light, and as little as
possible of that. Leave the box UNI
touched for three or four days; then
unwrap the plate and develop in the
ordinary way If your rock contains
an appreciable amount of radium you
will find on the plate an outline pic
ture or profile of the key or whatever
metallic object you may have used. 1t
will be more or less sharply Impress
ed according to the quantity of radi-
UNI present.
Outline on Plate.
If no metallic object were used the
effect Of suspending the ore above the
plate, or letting it lie upon it would
be to produce a general darkening of
the plate when it was developed. Such
a darkening might be produced by an
accidental exposure to light. The rea-
son for using the key is that the rays
from the radium are mostly intercept
ed by the metal, so that underneath
1t the plate is unaffected, and when
developed, shows the form of the key
printed light upon dark background.
If you get such picture after per-
forming the experiment just describ-
ed. with proper precautions, you may
be sure that there is radium in your
ore.
But to extract the radium-that is
quite another question! Until recently
all the radium ore found in the United
States has been sent to Europe to be
treated. Now a method of extraction
has been invented here. and we may
henceforth extract our radium at
home. At best the processes are long,
complicated, tedious and costly.
Per Cent Radium.
If you should discover an ore con-
tanning less than one ten-millionth
per cent Of gold you would hardly ex-
peet to make fortune out of It! You
would let 1t alone and look for some.
thing more profitable But that lis
about the percentage of radium found
in pitchblende, one Of the most pro-
ductive radium ores known. A ton Of
pitchblende contains about one milli-
gram (say, one thirty thousandth Of
an ounce) Of radium. 1t has been esti-
mated by sober reasoners that the to-
tai quantity Of radium In all the
known radium ore deposits in this
country does not exceed six ounces!
On the other hand. certain enthusiast
tic calculators have asserted that Col
orado alone contains far more than
that But what do you think that
their top estimate for the Colorado to-
tai is? Ten ounces.
You would have to tear down, grind
up, dissolve, precipitate, crystalline,
recrystallize, ..fractionate." and re-
fractionate a mountain as big as
Pixies peak, composed all of radium
bearing rock, in order to get enough
of the precious mystery to fill your
hat.