of
dazzling sunlight) lost her sight completely, but recovered it again at
the age of seventeen years after being treated with electricity. She had
to begin absolutely anew to learn to name colors like a child; all
measure of distance, perspective, size, had been lost for her _by lack
of practice_ (as O. Heyfelder relates in his work "Die Kindheit des
Menschen," second edition, Erlangen, 1858, pp. 12-15). He says, p. 12,
that the patient had been eight years blind; p. 13, that she had been
ten years so. Such cases prove the great influence of experience upon
vision in space, and show how little of this vision is inborn in
mankind.

When we compare the acquirement of sight by the normal newly-born
child and the infant with that of those born blind, we should, above
all, bear in mind that the latter in general could make use of only
_one_ eye, and also that on account of the long inactivity of the
retina and the absence of the crystalline lens, as well as in
consequence of the numerous experiences of touch, essential
differences exist. Notwithstanding this, there appears an agreement
in the manner in which in both cases vision is learned, the eye is
practiced, and the association of sight and touch is acquired. The
seventh case in particular shows plainly how strong the analogies are.

These cases are sufficient to refute some singular assertions, e. g.,
that all the newly-born must see objects reversed, as even a Buffon
("Oeuvres completes," iv, 136; Paris, 1844) thought to be the fact. My
boy, when I had him write, in his fifth year, the ordinary figures after
a copy that I set for him, imitated the most of them, to my surprise,
always in a reversed hand (Spiegelschrift, "mirror-hand"); the 1 and the
4 he continued longest to write thus, though he often made the 4 the
other way, too, whereas he always wrote the 5 correctly. This, however,
was, of course, not owing to imperfect sight, but to incomplete
transformation of the visual idea into the motor idea required for
writing. Other boys, as I am given to understand, do the same thing. For
myself, I found the distinction between "right" and "left" so difficult
in my childhood, that I remember vividly the trouble I had with it.

Singularly enough, Buffon assumed, in 1749, that the neglect of the
double images does not yet take place at the beginning of life.
Johannes Mueller, in 1826, expresses the same view. But, inasmuch as in
the first two or three weeks after the