The Washington times., 1920-07-25
Experiments That Seem
TO ShOU Our Visual
impressions of the World
About Us Are Only a Series
Z of Little Electric
By DR.. w. II. Ballou.
LTHoUGH the sense Of sight is o

nevertheless, in essence one OF the
great mysteries OF life. What is IT that
enables us by means of the small sphere
of the eyeball and the optic nerve leading
Z from II into the brain actually to see?
| What is 1t that draws within our brains
pictures of all the movements and all the
colors OF what is going on around us?
This mystery, in the light Of the newest
discoveries by science. appears to be on
the verge Of being solved, if. indeed, 1t is
not already solved Science now puts
. :. forth the theory that the sense OF sight is
: = an electrical phenomenon; that the retinas
:. of. our eyes upon which the rays OF light
-. which carry the pictures we see impinge
d are in reality collectors Of electrical i'm
.'tipulses, and that these impulses are carried
rhy the wires of the optic nerve into the
brain, and thereby a most cunningly ar
ranged mechanism converted into the fig
lures and colors which we call sight.
This theory has, curiously enough, been
built up from number of different
sources Of investigation working sepa-
orately ana independently. The English
~, body Of scientists whose experiments and
cal Magazine and Journal Of Science of
- London, Edinburgh and Dublin, were car
a ried to their conclusions by study OF
what it is that produces color vision.
They found to their own satisfaction that
color is the result of electrical discharges
p in the molecular structure Of the retina
set free by the impact Of waves Of light
Of varying intensities upon these struc-
lures. These electrical impulses carried
.4 on to the brain produce in the brain cells
which receive them the sensations which
we call red, blue. green, etc.
..,., It has of course long been known that
70 color is the result Of varying wave lengths
of the electromagnetic disturbance called
light. Slow waves of certain length pro-
duce what we call red. Extremely rapid
waves Of short length produce what we
call violet. The new point is that these
waves electrical in nature produce their
effect upon our visual organs electrically.
II. Winfield Secor membe, of the Amer
e.. ican Institute of Electrical Engineers and
an internationally distinguished expert
,r npon such matters, points out in the cur
rent number of Science and Invention,
formerly the Electrical Experimenter,
some other surprising discoveries on the
Bubject
'~~ In its simplest possible terms the mech.
ansm by which we see consists Of two
globes fitted with lenses through which
the light waves pass to strike upon a cur
tain at the back Of these globes which is
called the retns. The retina is an ex.
traordinarly complex structure composed
Of pigment cells, layer Of curiously
shaped microscopically small bodies called
=. from their shapes the rods and cones lay
n ers Of nerve cells and the flaments that
3" connect these rods and cones with the
cells.
Into the retina the optic nerve pene.
trates to about an eighth Of an inch, pre-
sentng at this point a small rounded ele-
vation perforated in its centre for the
passage Of the central artery Of the retina
'' There are, Of course, other elements in
d" the retinal curtain, but those mentioned
seem to be the only factors that are di-
:" rettly concerned with the reception OF
optical impressions-that is, they are the
mechanism that is the first step toward
cur seeing.
'''. The LAYER Of rods and cones is COM
posed OF small cylinders extending through
its entire thickness, closely packed and
tiving to the external surface the appear.
ance Of mosaic; between these is greater
or less number Of fask-shaped bodies
the cones This layer is about 1880 of an
inch in thickness at the middle OF the
retina 400 Of an inch about midway be.
tween the centre and the edge and near
the edge about 1880 Of an inch thick. The
ytds have diameter Of 1890 OF an inch.
ThAv a,n@cfcor, of rather fattened lustre.
soft and pliabie and somewhat brittle
II is a curious thing that shortly after
death each Of these rods shows under the
s microscope to become divided by deli
cate line into an outer and an inner seq
inent. The cones are OF the same consti-
tuition as the rods and about half their
length.
Upon this curtain fails the image that
. we see This image we do not see upon
The eve itself. II Is carried back by the
"wires' Of the optic nerve into the centre
In the brain where the image actually
comes to our consciousness.