The herald., 1896-12-06

light, the picture is on the bottom of the
film next the glass, instead of on top.
so the plate must be developed for long
time.
1 will now attempt a very difficult ex-
pertinent; difficult only because the light
is so faint it won't carry to you all
fear, as it will be decreased in strength
or intensity. of course, as the square of
your distances from the object. YOU
| will please notice l have had placed On
| the lower table square wooden pox,
within the box is a smaller Dox, also OF
wood The smaller box contains a me-
| tallic object. | want you to look right
| through the wooden cover of the box
and see the object with the aid of the
| fiuorescent screen interpoSed in 'front.' OIL
| it. The screen is a piece of paper COW
| cred with the salts of the tungstate OF
| calcium that become luminous when
| the X-rays go through the box and fail
| on them. The body in the smaller box
| is very dense. and the rays pass through
| with great difficulty; they go through
| the box itself easier, SO you may see the
| object in the box by looking steadily at
| the screen until the eyes become accus-
| toned to the darkened room.
| 1t is stated the X-rays are not refract-
ed; that is, the rays do not bend from
| straight line in passing from one sub
stance to another of different density;
as for example, when we look into
pool OF water, Ifle ray OIL DSHL WHICH
comes to the eye from the object,
say a stone on the bottom does not come
straight to the eye; it is bent at the
surface of the water where 1t enters the
air, forming an angle of something like
forty-eight degrees. And perhaps the
rays are not polarized as sunlight Is
on being reflected by mirrors which
change its character, some of its rays
having been quenched. Yet it has been
lately reported that the X-rays are diff
ferently absorbed by a pair of tourma-
line plates when their axes are crossed
OF paralleled; the rays passing through
more easily when the axes are in the
latter position better photographs be .
ing produced then; which would indicate
polarization when the aXees are crossed.
We are not yet sure that this distinc-
ton of refraction and polarization Is
evidence of a difference of X-rays from
light 1t may depend only on the
lengths of the waves as we are led to be-
lieve. Shorter wave lengths require
polarizers of much finer structure. The
X-rays appear to penetrate bodies ac
cording to their density, entirely iHde-
pendent of their other qualities; lead
with great difficulty; glass with less;
iron, etc, with still less trouble; and in
photographing the human body the
same law applies; the bones being of
greater density than the flesh it goes
through them with more difficulty; 1t
dUeclS the sensitive plates DeHlnQ tne1n
less, and so we get their shadows. Prof.
Lodge has in this way seen through
| yard of wood. Two lamps are now used
| in photographing, and focal distance OBJ
tanned; so we can locate the distance
| from the eye, say of a needle or bullet
in the muscles of any part of the body.
Most interesting of all, when the rays
are thrown on non-conductor of cleo
tricity it becomes a conductor; and,
further, under their influence the salts
of the metals, either solid or in solution,
behave generally as the metals them
selves.
X-rays do not exert any apprecable
effects on the combination of hydrogen
and chlorine as sunlight does, and un-
fortunately, they do not exert any in.
furious effect on bacteria, SO far as IS
now known. The effects of the ray or
the tissues of the human body are inter-
esting. Prolonged or frequent expos
ure of the skin to their influences sets
up an inflammation, true dermatitis
think you physicians would call it;
subsequently the tissues break down
and ulcers are formed If applied to the
scalp for long time the hair dies and
falls out.
1t is stated that with the aid of the
fluorescent screen ones heart, lungs
and other of the internal organs can be
seen, enabling us to observe the perform.
ance of their normal or abnormal func-
tions. This is true only with very pow
erful apparatus giving sparks to 10
! inches long.