Eaton weekly Democrat. [volume] (Eaton, Ohio) 1866-1875, 1872-05-30
CuriOsities Of Vision.

the power for estimating the distance OF
one object from another under water,
the magnifying lens of the eye of aquatic
| animals must necessarily be much more
| convex than inland animals.
A fish sees in the air just as we do in
| opening our eyes under water, indis.
tinctly. Submarine explorers are pro-
vided with glasses which meet the
| emergency.
Seals, frogs, terrapin, crocodiles, and
water birds, that seek prey alternately
in air and water, possess marvellous
mechanical provision for varying the
optic axis in passing from one medium
to another. Human eyes, having no
emergency by lens outside, as in wear
ing glasses.
No individual organ has been more
profoundly studied, nor is any depart
ment of science better understood than
optics, yet the sense of vision is not in
the eye, but far back in the brain. The
eye is simply a receiving instrument,
like a spyglass, directed by the will,
through which the conscious soul con-
templates what is beyond. Through
those organs the mind holds intercourse
with the world. Yet with such facts for
guidance, based on positive demonstra-
tions, philosophers have not been able
to explain how the mind operates on the
optic mechanism to see.
Insects are abundantly provided with
motionless eyes-but they see without
brains. They have ganglionic nervous
centers, and SO have we; but vision has
its location in certain white tubercles-
tubercula q,tadrigenaini. Spiders, flies, bugs,
even mosquitoes, with the incest kind
of distinct vision, both microscopic and
telescope, have nothing like brain.
Hair.
There are more applications than one
for the familiar metaphor about hu-
man life hanging on a single hair-at
least, very few hairs recently caused a
man in England to lose bis life upon the
scaffold. A doctor, who was somewhat
of an enthusiast on the subject of tho
microscope, had made special study of
all kinds of capillary teguments, and at
| upon the inspection of tuft he conld
tell from what animal it was taken, and
| from what part of the animal. Not
long ago he received a number of hairs,
| which he was requested to examine. He
| did so, and the result of his inspection
| was report that they were from hui
| man eyebrow, and that they had suffer
ed confusion. Soon after he was required
to attend the trial of man who was &C
| cused of murder. The victim of the
| crime had been killed by heavy blow
| upon the eyebrow with a blunt instru-
ment, and there had been found in the
possession of the prisoner a hammer
to which there clung the hairs which
| the doctor had examined under his mi
| croscope. Upon his testimony the man
was convicted-forming a notable in
stance of science assisting justice. But
one of the jurors, though agreeing in
the verdict, was haunted by doubts as
| to the reliability of the process by which
it had been reached. TO test the doc
| tors skill, he called on him one day
with lock of hair, and asked the sci
entist's opinion as to the original wearer.
The doctor replied after brief inspec
ton that it had been taken from the
back of a Norway rat. And such was
the fact Probably there are few ladies
| who would care to submit their supple
mental locks to the examination of this
unpleasantly accurate microscopist.