The Sedalia weekly bazoo. [volume] (Sedalia, Mo.) 187?-1904, 1885-07-07
COLOR BLINDNESS

/ Why should We hook one common faith ts
find
When one in every scoreis color blind7
II here on earth they know not red from
green,
VIII they see better into things unseeni
Allowing little for poetical license.
DIR. Holmes states very nearly the
truth when he says that one man out Of
every twenty is color blind. The aver
age is usually not quite so high as this.
although many scientists give it even
higher. 1t is safe to say that out of
every hundred persons, from three to
five will be found afflicted with that de-
feet of vision called color blindness.
Many persons have lingering sus-
picion that most of the diseases so
prevalent to-day, but uuheard of few
years ago, owe their existence to the
inventive faculties of physicians who
are supposed to spend as much time in
discovering new ailments as they do in
seeking remedies for the old. There is
nothing people in general are so much
afraid of as new disease or an old one
with a new name. People attacked
with what our grandmothers used TO
call lung fever and think of little more
account than case of measles, have
given up the ghost straightway when
told by the physician that they had
pneumonia. 1t was the name that
killed them more than the disease. So
when scientists first told men that
color blindness was among them, they
received as much gratitude as if they
had awakened a destructive agent,
which before was dormant if not dead.
"Where ignorance is bliss, It's folly
to be wise"
And yet color blindness has probably
existed since the time of Adam, al
though only lately known to science.
To Prof. Firthlof Holmgren, Professor
of Physiology in the University of Up
sala, Sweden, may justly be given the
credit of formulating the correct theory
of color blindness and also of devising
the simple tests by which it may be dis
covered. This was about the year
1870. His tests, or a very slight modi-
fication of them, are now in use wher-
ever it is necessary to examine men
with a view of discovering whether
they can clearly distinguish colors or
not. The King of Sweden carefully
read Holmgren's treatise on this sub
jest. and was so much impressed with
the facts therein contained. showing
the danger of having color blind men,
who, "a pilots or captains of ships or
engineers and conductors on railroads,
were obliged to Use colored signals,
that he ordered all the railroad en-
,loyes and sailors under his Govern
lent to be examined by HOlmgren's
tests for color blindness. The value
of these tests became known in other
countries and now throughout the civil
lied world itis almost universal custom
to examine all men for color blindness
who in their business should be able
clearly 10 distinguish colOrs- Railroads
especially have recognized the import
ance of the matter, as many accidents
are fairly well proved to have happened
through the color blindness of en-
ployes. The United States Govern
ment has also passed law compelling
all pilots TO submit to and pass an ex-
animation for color blindness before
they are given certificate qualifying
them to act
Color blind persons are divided into
two general classes-those totally color
blind or capable of distinguishing only
darkness and light, and those partially
color blind or able to distinguish some
colors and not others. The latter per-
sons may be totally red blind, green
blind. or violet blind, and they may
also be defective in one or all.
The totally color blind are very few
in number. and, of course, are aware
of their infirmity. The partially color
blind are more numerous and very
often ignorant of their defect. Color
blindness may be hereditary or it may
be the result of injury and disease. 1t
is very difficult disease to treat, and
when congenital is incurable. Cases
have been known where color blindness
has been inherited in several families
for as many is four generations, and
there Is no reason To think that it will
not exist in the blood Of these families
for al time to come ItdOeS not attack
every member of The family. but Ike
many other hereditary diseases. is un-
certain in its time of reappearing.
Some very curious mistakes have
been made by the color blind. An
architect had 10 release an apprentice
in consequence of finding him copy a
brown house in bluish-green paint, the
sky, rose color. and roses. blue.
A tradesman had a hired boy who
offered TO a customer pink and pale
green paper Is good matches, and who
kept getting his master in trouble by
binding books in wrong colOrs.
Many ladies report that when work
ing with colOred wOrsteds they must
have the Skeins marked.
A post-oilice clerk in Prussia was
found to be constantly in trouble with
the stamps. Sometimes he had more
money than the stamps sold for were
worth. at other times less. 1t was at
length discovered that he could not tell
raI - from, erraan