Idaho semi-weekly world. [volume] (Idaho City, Idaho Territory) 1875-1908, 1888-02-28
ooLoR.BLihoNEss.
-. .f Vision which IL Said % he
Osi rarreiy Hereditary.


r.. defect Of vision known as color
Sne.s Is very curious one. Ii
a'' 'is,s Of either total or partial lack
'op .h,llty to distinguish color. while
o. .trht may BIS fauiu.ss In every
lns sassoect When total. the sensa-
e aa # color is absolutely wanting.
u0a ,bs individual sees only different
'na ~. 81 white and black. These
'' however. are extremely rare.
eies common is partial color blind
A"' ,rbere the sen alton Is defective
n''N .t,on TO Ger ain colors. but not
~ This is of three kinds-red-
s,adness. green-blindness and violet
l u," Cases Of the last variety
H'" sel ,om met with that the term
blindness. as commonly used,
gnu. ,arence 10 either red-blindness
- creen- blindness.
D ,.ons wh1 are red-blind see all
i ohi4cts ~ a shade of gray. aud the
'.me i true of the green blind as to
'1 A mixture Of white and black
: nr,oer prop .rtions will give to the
ir.. h,ind the same sensation rs the
p "a ,.pt shades Of red and green 1t
!. .orswhat singular that while there
..son TO doubt that color blind
4. "a old az man, 1t was not dis
.'n.tlv recognized and accurately de-
''.;hsd until a little more than hum
dred years ago.
..oemaker named Harris. who lived in
W,vport England. 1t is said that his
e,.t suspicion Of any popularity Of
yi,jon on his part arose when he was
liant four years old Having by acci-
Amt found a child's stocking in the
.,,set he carried it to house near by
,oiuorire for the owner. He noticed
that other people called it red stock
,oo hut could not understand why
,hsv did so. as it seemed to him COM
nle;sly described by calling it a
.ocking. He observed, also. that
while the children with whom
/, bs played could distinguish
bs cherries on tree by some pre-
tended difference OF color. he could
ouly tell them from the leaves by their
difference in size and shape. He found,
Do that by means of this difference in
olor, or In some way which he could
not understand. they could see the
cherries at a greater distance than he
could. though in cases where their
,leht was not assisted by the color.
be could see objects at as great dis
lance as any Of them.
This case was described in 1777.
Seventeen years later the celebr ated
English chemist, Dalton. described his
own case 50 accurately and minutely
that color blindness in general. and
especially the form of it with which he
sas afflicted = namely. red blindness
Ia; since been known as Daltonism.
He says that he was never convinced
Of any popularity of his vision until he
accidentally observed the color of the
lower geraniuai zonale by candlelight.
The flower was pink. but appeared 10
him almost an exact sky-blue by day.
BIZ The light of the candle, however, it
seemed to him not to have any blue in
il being what he called red-a color
which forms a striking contrast to
bue. His friends, to whom he re-
iercd the matter, agreed that the
color was not materially different from
What it wis by daylight except his
BROTHER who was subject to the same
defect a. himself Two years after
ward he began to investigate the sub
ct Of colors. or color blindness. He
found that he could distinguish but
two or at most three. colors in the
rainbow. These were yellow and
blue, or yellow, blue and purple. His
yellow included the green, yellow.
orange and red Of others. This was
the same Dr. Dalton who afterwards,
though Quaker and conscientiously
opposed 10 wearing bright colors. when
be had received the scarlet gown
Of doctor of laws for presenta-
hon at court not only donned it with
Oal objection, but also wore it for sew
efai days upon the street. in happy
consciousness of the effect which he
produced.
COl.r-bindness is largely hereditary.
IND Affects males much more frequent
lyman females. 1t exis from birth,
.u taere Is no means known by which
can be remedied. A temporary
"aalton OF color-blindinss Is occa-
Aonally met with, due to disease OF
INJURY, which passes away with the
'OaaIion which produced it. The
'n''ence of color-blindness in persons
~gupylng responsible positions IN the
I1road and marine services is q
Surce Of great danger to the travel
Mspuoiic' and in most countries er-
4nauana ate provided by law, FIR
-sPurpose of testing the color-per-
sslOa OF all applicants for these
F''''na-Goiden Days.