The morning news. [volume] (Savannah, Ga.) 1887-1900, 1896-12-07
smaller gangalia in the fingers direct the

smaller gangalia in the fingers direct the
forming of the o.
For certain novel experiments which
have to do with ma alters of this kind Prof
Gates has newly constructed a room,
which is beyond question the darkest place
in the world Ordinarily when one
speaks of darkness, it is in a comparative
sense. The darkest night is not very dark
out of doors. The depths of cavern or
coal mine are darker but not so dark as
the so-called dark room" of a photo
grapher. Yet a very sensitive plate ex-
posed in Photographic dark room is
quickly spoiled. because some light is
present. On the other hand the darkness
obtained by Prof. Gates is absolute. Com
pared with 1t, the darkest darkness hith-
erto known might be bottled up and sold
for Tyrian dyes" The vatican at Rome
actually possesses a bottle full of the
darkness which afflicted Egypt when the
lsraelites wanted to get away, but it is a
rainbow when contrasted with the scien-
tific brand of darkness. Unlike the Eyp-
tian darkness, this darkness cannot be
felt; it is too dark for that.
Prof. Gates dark room is con-
structed like a box, the walls of which
are of wood saturated with paraffine, to
fill the pores. There is a lining of tar
paper, and then come layers of orange
colored paper. gray felt paper, and lead
foil. The purpose of these Innings, of
course. is to exclude all light rays. In
side of the box described is another
box similarly made and lined, and within
the second box is a third box, which has
walls of sheet lead and of wood painted
black. But lead is not wholly opaque to
X-rays, and so a microscope screen is
placed beneath the sheets of that metal
Such x-rays as get through the lead are
stopped by the screen and turned into
1s~-1.t I-kk ~
black painted wood. The wood is covered
with twelve layers of paper saturated
with chemical substances that are Opaque
to light of various colors. These are
oVerlaid by three additional layers con-
tanning salts Opaque to the invisible rays
of the spectrum beyond the violet, and
finally there is coat of lead foil. The
innermost room rests on rubber cush-
ions; the second room is similarly sup
ported. and the third or outermost is in
sulated and rests on posts which go deep
into the ground. Electricity is conveyed
into the nnermost box by wire cable
from a friction machine outside. Thus
the whole affair is a great Leyden jar,
within a Leyden jar, within Leyden Jar.
The innermost box, which is the dark
room. is so absolutely dark that the most
sensitive Photographic plates, exposed
there for forty-eight hours, have not I'M
dergone the slightest alteration. 1t is
likewise impenatrable to x-rays, to the
dark heat rays below the red of the
spectrum, and TO the invisible rays above
the violet. 1t is proof even against
sound waves of certain classes, such as
musical tones. The dark room is entered
by sort of labyrinthine passage, which
winds around the nest of boxes until the
entrance to the innermost one is reached.
1t is brilliantly llumined by electricity,
but touch on a button brings instanta-
neous blackness. After getting used to it,
you are able to distinguish finger before
your face. very family. This is due to
phosphorescence in the eye; after a while
it fades out and you can see nothing what
ever.
Certain sense perceptions seem to be
more delicate in the dark than in the light,
and Prof. Gates wants to measure them.
This is one of the purposes for which his
black room is built; but its construction
renders practicable the solution of other
important psychological problems. AS has
been said, the room is actually a big Ley
den jar; it can be charged with electricity.
Already it is more than suspected that the
mind works more quickly and better when
the electric potential of the surrounding
atmosphere is high, and contrariwise when
it is low. There is no difficulty in raising
the electric potential of the dark room as
high as may be desired. Then exact tests
may be applied for ascertaining if the
senses are rendered more keen and the
mental processes more rapid Science has
already devised dozens of machines for de-
termining such things-as, for example to
determine the threshold of feeling, hear
ing, etc. The threshold of hearing is the
least sound one can hear; that of feeling.
the least touch one can feel; and likewise
with the other senses