The citizen. (Frederick City, Md.) 1895-1923, 1897-01-22

have tested no less than $50 different
forms of vacuum tubes in order to find
out which was the most efficacious in
producing those rays and he also tried
a great variety of chemicals in order to
ascertain which would be most service
able in direct visual Investigations. II
will be remembered that X rays are ca
pable of producing two effects. One is
to impress a Photographic sensitive
plate, the other is to make certain sub
stances emit faint blush glow. Sum
light also excites these substances in
the same manner, and the phenomenon
has long been known as huorescence,
because "fluor spar" is mineral having
this quality to some extent. But fluor-
escence has been only a scientific curl
osity until recently. 1t was not useful
for any practical purpose. Therefore
no one has had much incentive to hunt
for the material possessing the proper
ty to great degree. Prof. Roentgen
in some of his experiments used paper
that had been coated with what chem
lists call platinc-cyanide of barium, this
being as susceptible as anything he
knew and could readily obtain. But
Mr.. Edison discovers that salt
known as tungstate of calcium is
six times as sensitive, and no doubt
every one who makes the new observ-
ing instrument, the microscope, or
crytoscope, or skotoscope, as it is
called, will be glad to take advantage
of this fact
A convenient form of this device Is
a light box, about eight inches long,
five inches wide at one end and trifle
more at the other, and varying in depth
from three to four inches at the mar
row end to five at the wide end. The
sides, top and bottom are of opaque
material, wood or cardboard. The
small end is left open, and is shaped so
that when one looks into it the edges
will fit snugly against the forehead and
exclude all ordinary light. The fur
Their, larger end, is covered with a sheet
of stout paper coated heavily with flu
crescent material. A convenient ham
die underneath enables one to manage
1t easily, but if the user wishes to have
both hands free he can attach to the
sides of the instrument a band which
will encircle his head and hold the de-
vice firmly in place.
Now let a man stand with his fluoro-
scope at his eyes and face the end OF
a vacuum tube from which X rays are
being projected. The distance between
the two pieces of apparatus should be
as short as convenient, say foot. And
let another person interpose plate of
aluminium a quarter of an inch thick,
Or piece of wood two or three inches
thick, and also his hand, between the
vacuum tube and the fuorescentscreen.
The first person will then see, from
the inside, the faint illumination on
the coated paper and shadow of the
hand. If the apparatus is all in good
condition the center line of each finger,
the bone, will look darker than the
fleshy covering. A gold ring will give
very dense and noticeable shadow.
Similarly if there are buckshot in the
flesh, their position can be detected,
as can any motion of the hand or u
single finger. OF course, if the alumni
mum plate be removed one sees much
better, and in practical service this and
other needless barriers will be discard
ed 1t is only to exhibit to curious and
skeptical people the wonderful pene-
trating powers of the X rays that the
Snowman uses them. Mr.. Edison and
other scientists are hopeful that with
powerful vacuum tube and very
sensitive Horoscope it will be possible
to explore almost every part OF the hui
man body. Mr.. Tesla has photographed
a man through his chest so as to show
the ribs. The bones were not clearly
defined, but nevertheless were appar-
ent. In time much better pictures will
be possible; and the Horoscope, it is
believed, will enable one to see every
thing that can be photographed. and
more. You can't photograph heart
beat, but you may be able to see one.
No wonder that the whole scientific
world has gone half crazy over Roent-
gems astonishing discovery N. Y
Tribune.
chocolate Caramels.
One can on condensed milk, half
pint of sweet cream; mix and reserve
one-fourth pint of the mixture. To
the rest add one and half pounds OF
sugar, three-fourths pounds of glucose.
and cook over slow fire until half
done, then set off the stove. Break up
two and half ounces of the chocolate
used for frosting and put it into q
basin with little water; put on the
fire and when hot add the reserved
cream. little at time, until the choco-
late is dissolved; strain into the candy
which has been cooling, and set on the
fire nnain and nnnls 20 ssr.rRA n..n..l. -