The new North-west. [volume] (Deer Lodge, Mont.) 1869-1897, 1889-12-06

a Little Mirror Disk That Has Made Oph-
= thaimic SCIENCE What 1t Is-lt IL Quite
New Invention-Near Sieltetlncss Conn
mon Amcns the Ancients.
II would like to examine the interior of the
eye" said the oculist. But, when he per-
ceived slight shrinking on the part Of the
reporter, who assumed for the time the role
OF patient, he smilingly added: sYou need
not be alarmed; it will not hurt you a parti-
cle"
Then picking up little disk SHAPED mirror
with hole through the center he led the pa
tient into q dark closet, aud after lighting
bright gas jet told him to sit down on the
chair Immediately beneath it. Next, he him
self sat down opposite, SO that the knees n
the two touched, and held the small round
looking glass in front of his own eve, like an
eyeglass, with the mirror side outward, in
such manner that it reflected raw from
the gas jet straight into the patients eve
through the pupil. He could direct the raw
easily enough, inasmuch as he was looking
along it through the small hole that pierced
the center Of the disk. If you will hold u big,
hat button mold up to your eye and look
through it at the eye of person seated in
front of you you will get notion of the way
i'll which the oculist operated. Suppose the
button mold las quicksivered glass on the
surface turned toward the object, and you
will perceive how easy it would be to throw
Il ray reflected from II light above the other
persons head directly into that other per-
sons eye, and to watch, through the hole in
the button mold.
WHATEVER THAT RAY REVEALED
This was what the oculist was doing with
the mirror disk. The ray it reflected entered
the patients eye, through the pupil, and
lryl,tG l1yt, into,
room is lighted up by bulls-eye lantern
shining through doorway from outside
Just as the lantern might be turned about
this way and that, to illuminate various parts
of the darkened chamber beyond tho door,
way, SO the little looking glass was manipu-
lated between the foreinger and thumb of
the physician, as he held it before his own
eye, i'll such Il manner as to reveal to his view
every portion Of the inside of the ocular
camera obscura-for such the eye is; very
much like the camera Of the photographer in
its construction and mode Of working; and,
by gravy! it has been found out quite re-
Gently that the so-called ocular purpen in
the eye actually produces the pictures Of OBJ
lects seen on the nerve screen that lines the
organ, by chemical process very much like
that employed by the photographer to bring
ont the lines Of his negatives. Possibly some
day by studying natures method, the sun
print artist may learn how to photograph
colors rs the eye does. Who knowsa
The patient was very much relieved at
length to hear the ocuist say that there was
nothing serious the matter. .."~..3.m4. -. ..u
81 observe slight inflammation of the III
ner coat of the left eye" remarked the ply
sicifl, as we'll as q mildly hypera,mic con
diiion Of tile lids, both Of which little troubles
have undoubtedly been occasoned by tho
fri;.sSas yt1 Irnnr y ."@o 8%lII E0.
What is the little round mirror called
with which YOU examined my ewes iuside2n
asked the patient while the oculist was en-
gagged in fitting glasses Of various strengths
into il hugo nose frame for trial
To that little instrument y RESPONDED the
Surgeon '.is due nearly all Of tic progress
made in ouhtL,luic science since thn dave ~
the ancient Egyptians, 5000 Years ago. And
yet, as yo,l see, it is nothing but d small.
round mirror with a hole through II IL is
called The ophthalmoscope. and was invented
hy Helmholtz in 1862. So few Years ara os
that VERY little was known about the eve ht.-
yo,lel what the old Egyptian physicians were
acquainted with However, as to the oph
thamoscope | wa, roiup to saw that If af-
fortied the first means ever discovered for
studying the interior of the livingev From
that point modern ophthalmic science really
took its rise, anil there is not much about The
cy. today TINT is not understood
NEAR SlGITEDSEsS AMONG THE AScIESTs
''Werp people afflicted with nrur sighted
t.~s in ancient tilnes;"
t>OA, ves: though probably not 10 the
same extent. We read, write and study
mere than the ancients did, and for this rel-
SON near SIGHT is more common with MS for
i, is tic excessive use of the eyes MT Tho
near point that propagates the trouble. In
old times troubles with the eyes were regard
| cd as Affections sent by heaven, for which
| there was no er1e. Nero, who tiddleii while
| Rome was burning, was so near sighted thut
| although he had the very best seat in tho am
| phi;heatr1 ut the gladiator shows. he
| could not SEQ what was going on Ono {ny
| lie discovered that Il certain concavn emerald
| il his collection of jewels aided his vision
| materially, and from that time he always
| carried lEe emerald about with him nul
| ,vI,n., hu ,,,,ttpI Ia vnn =ourtl,;,fr at :, d;