Daily globe. [volume] (St. Paul, Minn.) 1878-1884, 1879-11-09
COlOr.BIfndneSS.

C0l0r.BIfndness.
From q review in Scrih7aer Of DR..
Jefries' book on this subject, we take
these interesting facts =
Holmgren's plan for the determine
tion of color blindness does not con-
tain anything original either as regards
the materials (colored Berlin wools), or
the method comparison of colors and
shades independent of their names).
Seebeck had used the materials and the
method years before What Holmgren
did was to shorten the method without
!essening its accuracy, and thus make
it practical for extensive examinations.
BY Seebeck's method more than twen-
ty-tive persons could not be examined
IN an hour, whereas, according to Holm
green's plan, hundred or more can be
examined in that time. Holmgren's
method is as follows: A large assert
ment of Berlin woods of all colors and
shades of color Q50 to 200 skeins) is
spread before the person to be exam
med, and bright green skein (not in
Ginning to either yellow or blue) is laid
aside as sample" He is then tod to
select from the pile those skeins which
appear to him Of the same color but of
different shades, I. e., lighter or darker.
If he can make this selection properly
he is not color-blind. If, however, he
lays by the sample" other colors, par
ticularly brown or gray, he is color
blind. This examination, when the
person examined is one of ordinary in
telligence, is made in a minute, or even
less time, and the question of color
blindness is settled. Practically, this is
sufficient, but, if it is desired to know
the particular color to which the indi-
vidual is blind. another examination
must be made. At present three kinds
of color blindness are recognized-cor-
responding to the three so-called pri-
mary colors, red, green, and violet or
blue. As violet, or blue blind
ness, is exceedingly rare, an ex-
animation as to the first two
is sufficient, particularly as they are the
two colors most important in practical
life. In this second examination, a
pure purple is laid aside as sample
and the person examined is told to Sc
lect shades appearing to him like it. If
he selects grays or green's he is green
blind; if violet or blue he is red blind !;
if orange or yellow he is violet-blind.
The results of examinations
made in various parts of the world to
this time, aggregating over 100000,
show that one male in about every
twenty-five whites a per cent)i is color
blind in greater or less degree. It
would seem from limited number of
examinations of Jews by COIN and
Magnus, in Breslau, that this race is
more subject to color-blindness than
Christians, and from some examina-
tions by DR.. Swan M. Burnett, of Wash
ington, of the negroes in the public
schools of that city $3.50 in number),
it appears that that race is less affected
with the color-blindness than the white
race. The female sex is rarely affected
only about one in 400. As rule the
defect is congenital, though it is some
times acquired through disease, and it
is frequently hereditary.
The Importance of true sense of
color to railway and marine employees,
where the lives of many persons depend
on proper discrimination between a
red (danger) and green (safety) signal
is apparent, and it is evident that law
should be passed requiring an examina-
ton of such employees in respect to
their color-sense. DR.. Jeffries sue
ceeded in having such q law passed bv
the Massachusetts, Legislature, and it is
to be hoped. in the interest of humani-
ty, that the matter will be pressed to
the same result in all the States, or in
our national Congress.
Suffering.
Mr.. Edgar 8. Werner recently read
before the Albany Institute paper on
this subject. MI. Werner himself was,
at one time, afflicted with this terrible
disease, and he says that parents almost
invariably treat a suffering child with
much severity, and thus, by frightening
him, increase his malady, or spoil him
utterly by too much leniency. The
proper manner in which to treat such
children is thus described: In nothing
is the adage, IAN ounce of prevention
is worth pound of cure" more appli-
cable than in suffering. Indeed, in
this instance, an ounce of the one is
more effective than hundredweight of
the other. Children with suffering
tendencies should be especially well
nourished; they should take a great
deal of physical and outdoor exercise;
care should be taken that their lungs
are fully developed and that their nerves
are not irritated. Late hours and
bighly-seasoned food, and everything
tending to derange, weaken or unduly
excite, mentally or physically, should be
avoided. The child should not be al
lowed to talk too rapidly or when out
of breath. If he has trouble with a
word he should be asked to repeat the
whole sentence and not merely the
offending word. Oftentimes a serious
mistake is made here. The child is
drilled upon his most difficult words,
and he comes to fear them, and, as a
result, his ability to articulate them is
continually lessened. He should not
bepermitted to associate with another
suffering child; indeed, no child
should. Inveterate suffering may be
caused by mimicking others. Through
out, the child should be subjected to
kind but firm treatment.
A Texan Abroad.
A Texas penflannan nonood G,oc,o1