Eagle River review. [volume] (Eagle River, Wis.) 1890-1927, 1896-03-05

pace with the interest OF the subject, and
Prof. Whitman, of the high school at
Buda Pesth, has reduced the time neces-
sary to obtain a Well-defined Roentgen
photograph to three minutes under ordi-
nary circumstances, and thirty seconds
under perfect conditions.
No substance is impervious to this new
form of radiant energy. Matter against
which ordinary light rays beat helplessly,
and from which they are thrown with 4
power apparently greater than their strik-
ing force, are as open gates for the X
rays. On this point Roentgen, the pioneer.
says:
The most striking feature of this phenom-
enon is that an influence capable Of exciting
brilliant duorescence is able to pass through
none of the ultra violet rays of the sun or
OF the electric arc, and one Immediately in
quires whether other bodies possess this
property 1t is soon discovered that all bodies
are transparent to this influence, but in
very different degrees. A few examples will
suffice. Paper is very. transparent. The
ume of 1000 pages still lighted up brightly
the printers ink offered no perceptble OBJ
stacle. Fluorescence was also noted behind
two packs of cards; a few cards held be-
ceptible difference. A single sheet of tin
foil is scarcely noticeable; only after several
is a shadow clearly visible on the screen.
Thick blocks of wood are. also transparent;
fir planks two or three centimeters thick
are but slightly opaque \, lin moi aluminium
effect very considerably, though it does not
entirely destroy the fuorescence Several
centimeters of vulcaniZed India rubber let
the rays through. Glass plates of the same
thickness behave in a different way, accord
ing as they contain lead (fint glass; or not;
the former are much less transparent than
ha Ia hp IA is
discharge tube and the screen the dark
shadow of the bones is visible within the
bisulphide of carbon and various other
liquids behave in this respect as if they were
very transparent | was not able to deter
mine whether, water was more transparent
than air. Behind plates of copper, silver,
lead, gold, platinum, fiuorescence is still
clearly visible, but only when the plates are
not too thick Platinum or mllimeters
sheets may be decidedly thicker Lead 10
millimeters thick is as good as Opaque, and
was on this account often made use of. A
wooden rod of 2Ox2O millimeters cross sec
ton, painted white, with lead paint or one
side, behaves In peculiar manner. When
it is interposed between apparatus and
screen it has almost no effect when the X
rays go through the rod parallel to the
painted side, but 1t throws a dark shadow
similar one rays to the metals are their
SALTS whether solid or In solution.
The reports of Prof. Roentgens ex-
periments produced great activity
among students everywhere. Newspa-
pers and scientific journals were filled
with reports of the labors and new dscov-
cries made. There is not an institution
of learning or laboratory worthy the
name in America where the Roentgen
method of photography has not been put
to practical test. One remarkable die
covery was made incidental to some ex-
perirnents in New York. Prof Max Os-
tenberg. of Columbia College, desiring to