Watertown republican. [volume] (Watertown, Wis.) 1860-1906, 1885-10-07

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 devisno
the simple tests by which it may be dis
covered. This was about the year
1870. His tests, or very slight modi-
hcation of them, are now in use wher-
ever it is necessary to examine men
with view of discovering whether
they can clearly distinguish colors or
not The King of Sweden carefully
read Holmgren's treatise on this sub
iect, and was SO much impressed with
the facts therein contained showing
the danger of having color blind men,
who, as pilots or captains of ships or
engineers and conductors on railroads.
were obliged to use colored signals,
that he ordered all the railroad en-
plOyes and sailors under his Govern
ment 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 tits almost universal custom
10 examine all men for color blindness
who in their business should be able
clearly to 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 soma
colors and not others. The latter per-
sons may be totally red blind, greer
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 infrmity. 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 in Jury and disease. It
is q 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 as four generations, anG
there is no reason to think that it will.
not exist in the blood of these families
for all time to come Itdoes not attack
every member of the family. but like
many other hereditary diseases, is un.
certain in its time of reappearng.
Some very curious mistakes have
been made by the color blind. An
architect had to 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 hired boy who
offered to a customer pink and pale
green paper as 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-office 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
red stamps from green.
A sea captain who used no work en-
broidery when time lay heavy on his
hands lost all appreciation for colors
by everlasting his eyes and was after
wards unable to distinguish red worsted
from green.
An amusing story is told of Dalton,
the celebrated English chemist He
was a Quaker, and although about to
be presented at court, was unwilling to
wear the scarlet robe of a doctor of
civil laws, as scarlet is forbidden to
Quakers. But Dalton was color blind,
and when offered the scarlet robe he
was unable to see anything strange in
it, and not only wore it at court but
also on the street for three or four
days, until his Quaker brothers in con-
versation expressed their horror at see
ing him so attired. Dalton was so
! chagrined that it is said he burned the
robe.
Color blindness has been found very
cOuluOu dLuOuS SdllOIS anu sea cap
tains. Prof. Holmgren found, out of
1000 Swedish sailors, ninety-four color
! blind, and this is about an average of
this disease, found in the examinations
of pilots in this country. The increase
Of collisions at sea is an indisputable
eact. How many remain unexplained
Or are referred to another cause which
are no doubt due to the color blindness
of a single man. If good color per-
ception is necessary anywhere, it is On
sea. After the loss Of the French YES
sci Vile du Havre, the newspapers
stated positively that the green light
was not recognized in time. The
English, Admiralty decided that the
English sailing vessel was free from
blame in the collision, and the French
Admiralty exonerated the officers of
the French ship. Many scientists, how
ever, believe that the cause of the acci-
dent was color blindness in the officer
of the watch of either of the vessels.
Mapu other axamo1aS 1niUht ha CrivaO