The record-union., 1896-04-30
EDISON'S FLUOROSCOPE.
The Wizard Happy Over the Perfection
Of His Apparatus.
Through an Inch and Quarter Plank
the Reporter Saw His Bones
Clearly.

Thomas A. Edison, who has har-
messed electricity and made it the serv-
ant of his will, was in a peculiarly
happy frame of mind when I saw him
at his laboratory, in Orange, N. j., yes
terday afternoon. He was putting the
finishing touches to an apparatus on
which he had been working for some
time, and which he designed to be a
valuable aid to surgeons in connection
with the mysterious X rays-that sub
tie something which has the power to
reveal hidden and invisible objects.
1T is all very nice" said Mr.. Edison,
i'll his chatty way, ito get the X rays
and to photograph the invisible, but the
thing is to turn this wonderful discov-
cry to practical account to make a use
of 1t that will be a benefit and a bless
ing to mankind. This, of course, will
be done when we make it useful ad-
Junct OF the surgeons profession.
When the news of Professor Roent-
gems marvellous discovery reached US
we all began experimenting with the
rays, and were enabled to picture the
bones in the hand, the bones of the
arm and the bones Of the leg. And it
was thus early determined that if any
the bones they could be promptly locat-
ed and revealed, thus helping the sur
geon in his work of removing them
But this had to be done with the aid of
highly sensitized Photographic plates,
and in that process a good deal of time
was lost. The person whose arm or
hand, for example, was to be photo
graphed had to sit under the X rays
fa, ,1,i1
even an hour and a half. Then the
Photographic plate had to be devel-
oped, and that also consumed time
My aim has been to devise means
whereby the surgeon could see in an in
slant the nature of a fracture of a
bone or the location of foreign sub
stance. And all my experiments of
late have been to that end.
''As is well known Mr.. Edison went
on, ''the chemical compounds used in
the makeup Of sensitized photograp phic
plates turn the x rays into light, and
it struck me there ought to be some
chemical that would do the work quick
er and better than the chemicals now
generally used.
PURSUIT OF A CHEMICAL.
I'VE started out to get a chemical
that would, to be technical, fluoresce
quickly and satisfactorily, because, as
is well known, it is the fluoresence of
the x rays that reveals the hidden OBJ
jects. We tried eighteen hundred chem
icals and found that seventy-two would
fiuoresce readily with the X rays, but
the one we found best of ALL and which
produced perfectly marvellous results,
was tungstate of calcium crystals.
These we found f1uoresced Immediate
lN We stopped photographing, be-
cause, in the course of a few expert
ments, we found we could see with the
naked eye in a moment what had pre-
viously taken a long time to show by
means of the Photographic plates"
Mr. Edison went ON to describe the
practical application that he made of
his discovery. He had a box on the
principle Of a Photographic camera,
wide at one end and narrow at the
other. At the smaller end he attached
pieces of cardboard to fit over the eyes
and exclude all light. On the larger end
of the box, which, by the way, he has
called "the microscope" he placed a
piece of cardboard, and on the inner
side of the cardboard pasted a piece Of
white cloth which had been coated with
tungstate of calcium crystals. His lab
oratory, as everybody knows, is prob
ably the best equipped in the world,
and it does not take him long to get
apparatus ready for any experiment
LOOKING AT HIS BONES.
He placed a vacuum tube of his own
make on the mercury pump, and. after
it had been exhausted of air, turned the
current of electricity into it from an in
duction coil. The tube fluoreSced in a
moment Mr.. Edison put his hand in
front of it, placed the Horoscope over
his eyes and saw at a glance that on
the white cloth there were distinctly
pictured the bones of his hand. Not
vestige of flesh was visible, SO that it
was clearly demonstrated that with the
use of the Horoscope and Crookes tube
a surgeon could determine in a moment
the nature of a fracture in the limb of
O patient or the location of a foreign
substance, like bullet, in the bones.
"You see,'' said Mr.. Edison TO me,
"the x rays, in going through the hand
and outlining the bones in it, are turned
into light when they strike the cloth
coated with the tungstate Of calcium
crystals; that is why we see the bones
SO clearly.
Here" he said quickly, as he turned