The Portland daily press., 1896-01-18
HIDDEN SOLIDS REVEALED.
Prof. Rontgen's Experiments with
CrOOkes's Vacuum Tabe.
BULLETS FOUND BY USING
LIGHT
USING

Opaque Bodies Covered by Other Bodie
Photographed-vlews of Profs. o. N
Rood and Halleck of Columbia.
IN. Y. Times.)
Men of science in this city are awaiting
with the utmost impatience the arrival of
European technical journals, which Will
give them the full particulars of Prof.
Routgen's great discovery of method of
photograrhing opaque bodies covered by
other bodies, hitherto regarded as
wholly impenetrable by light rays OF any
kind.
Prof. Routgen of Wursburg Univer-
sity has recently discovered light which
for purposes of photography, will pene-
trate wood, paper, flesh, and nearly all
other organic substances. Thus, the
bones of the human frame can be photo
graphed in relief without the flesh which
cover them, or metals inclosed in a box
covered with a wooden cloth can be photo
graphed as if the cloth and the wood did
not exist.
In one sense, 1t is misnomer to call
the process photography, as now under
stood, because no lens is employed to pro-
ject the image. 1t also seems, from the
brief accounts of the process which have
already been sent Ky cable, that the new
images of concealed bodies resemble
rather the old-fashioned daguerreotypes
than the modern finished photographs,
inasmuoh as they appear only in outline.
Briefly, the new images are obtained
by the energy given out in .Crookes's vac
uum tube. The object to be photographed
Is placed behind the tube, and dry plate
is placed behind the object. If the object
be, say, hand, the image on the dry
plate will be the bones in it, without
any flesh covering whatever. !
Prof. Routgen has already used his
process to detect the exact location of bull
let's in gunshot wounds, and one of its
first practical uses is expected to be a
transformation Of modern surgery by en-
abling the surgeon to detect the presence
of fureigu bodies of whatever kind in any
part Of the huamn body.
The germ of Prof. Routgen's discovery
is to be found in an experiment made a
few years ago by Prof. William Crookss.
He found that when a glass bulb from
which all the air possible has been OK
traoted has current of electricity passed
though it.a beautiful light in the interior
of the bulb is the result. 1t now body.
whether transparent or opaque. is placed
bet9 cen the polos between which the cur
rer ;ssssa in the vacuum, sharply defined
Sis Hs of these bodies are projected on
the wall of the bulb behind the negative
pole.
cit seems" says Prof. Sylvanus Thorn
If the transparent or opaque bodies
stopped the way for some of the flying
molecules and prevented them from strik
ing the opposite wall.
Hertz, the great electrician, better
known in connection with the Panama
scandals, discovered that while these rays
will not pass through glass, mica, or any
transparent substance, they will pass
through thin sheet of metal foil.
Lenard, by using a window of alumni
mum foil at one end of the bulb, succeed
ed in making the rays pass out into the
atmosphere, where they excited phosphor-
essence. Hertz made the shadows appear
In ordinary air by covering the negative
pole of an electrical machine with silk,
on which the shadows werp thrown.
Prof. o. N. Rood, who occupies the
Chair Of Physics in Columbia College.
was asked yesterday by q reporter for
The New York Times IL this discovery
was in line with the previous anticipa-
lions OF men of science. Although the in
formation which the reporter was able to
give Prof. Rood was of the briefest char
acter, he kindly consented to explain the
analogies which occurred to him as hav-
ing any bearing on the new discovery.
"The phenomenon which we call light, >
said the professor, lis peculiar mani
festation of energy in the ether which
pervades ALL substances. 1t consists of
short vertical waves, roughly speaking,
for one-forty -thousandth to one-sixty-
housandth of an inch in length. These
waves are visible to our eyes only for the
length of the spectrum, which displays
the component parts of white Ii ght, from
red to violet.
The most familiar example of the spec
trum which we have is the rainbow. Men
of science have been long aware that
there are rays of light imperceptiple to
the senses. For example, in that part of
the spectrum beyond the violet rays there
are rays which. though imperoeptible to
our eyes, can be seized by the sensitive
plate of Photographic apparatus 1t SO
happens that the violet and the ultra
violet rays are those which are chemi-
DAILY the NEST active. At the red end of
the spectrum we have every reason to be-
lieve that there are other rays imperoepti-