it to have our engine drivers with perfect color perception, where
one man alone watches the signal of safety or danger.

The growth of our railway system is constantly increasing. We have
to-day probably 150,000 men employed in this service. The boys
attending public schools to-day in a few years will have to fill the
ranks of these men. How important for these boys to know that they
have not this defect. If the forty boys in every 1,000 are found, what
is to be done with them? The engraver, the wood cut engraver, the
etcher, all wish apprentices. I am also informed that these
occupations pay well. It requires talent to fill them, and here is an
opening for the color blind. Hear what a color blind writes:[4] "I beg
to offer some particulars of my own case, trusting it may be of use to
you. I am an engraver, and strange as it may appear, my defective
vision is, to a certain extent, a useful and valuable quality. Thus,
an engraver has two negative colors to deal with, i.e., white and
black. Now, when I look at a picture, I see it only in white and
black, or light and shade, and any want of harmony in the coloring of
a picture is immediately made manifest by a corresponding discord in
the arrangement of its light and shade or, as artists term it, the
_effect_. I find at times many of my brother engravers in doubt how to
translate certain colors of pictures which to me are matters of
decided certainty and ease. Thus, to me it is valuable." Having
already spoken about the importance of having all boys undergo an
examination for color blindness once in their school lives, we have
two very good reasons for making this suggestion.

[Footnote 4: Wilson, p. 27.]

First, prevent a boy following a trade or occupation where he is
incapacitated, and, secondly, let him be trained for a certain trade
or occupation when the defect exists. The savage races possess the
perception of color to a greater degree than do civilized races. I
have just concluded an examination of 250 Indian children; 100 were
boys. Had I selected 100 white boys from various parts of the United
States I would have found at least five color blinds; among the Indian
boys I did not find a single one. Some years ago I examined 250 Indian
boys and found two color blind, a very low percentage when compared
with the whites. Among the Indian girls I did not find any. When we
know that only two females in every 1,000 among whites are color
blind, it is not surprising