The Cecil Whig. [volume] (Elkton, Md.) 1841-current, 1880-05-08
THROUGH THE MAGIC GLASS.

Turn where we Will,
The Olplcr book of Nature opens still
This way and that: the two intintieS,
Sublime alike, in the Vast Spaces this,
That iii the Mnim Worlds, alike proclaim
With coSnic eloquence His awful Name
The telescope. the seer Of the far away,
makes us feel the insisnitcance OF man and
Of mans earth but that inSgnificance be-
comes sublime when we turn to the micro
scope. the seer of the infinitely small, the
fitting complement To the instrument which
gauges the star depths, and resolves nebulr
into systems of worlds Chalmers says
that as the one is constantly widening the
circle OF the Creators territory, so the other
is As constantly filling up its separate por-
tons with all that is rich, varied, and beau-
tiful.
The art Of grinding glass lens, made con-
veX on one or both Sides and used as mag
nifying glasses, was familiar to the ancentS
and in the Middle Ages. The lens, so called
from the Latin word for leWH Il plant
whose seed is round and Il little convex in
the middle, was early employed in the in
sl1ection of minute natural objects, and in
this connection soon received the name Of
microscope, meaning i'll Greek little, and to
see.
The principle on which the convex lens
helps the sight is very simple. All bodies
emit light whether original or reflected
and it is this light which makes them WISH
bic. Rays starting from every point Ill Il
body enter the pupil of an eye, and passing
through the crystalline lens behind it, con-
verge on the retina, thereon painting the
images of the outside world. The eye is the
most perfect possible optical instrument
those made by art taking its constructions
Tor their model, and only by so doing they
succeed in aiding its natural powers or
modifying its accidental defects. In the
case of most persons the object has to be AT
least five inches from the pupil before its
image can converge on the retina: and
When objects are so very minute that
they have to he held closer than this
To the eye, the rays diverge so that
they cannot be seen at all. Now =
lens placed between the object and the
eye causes the rays TO divcrge less, by
throwing what is called the focus farther
back. so that the image is enlarged and
seems more remote than it really is. If we
try to touch a piece of paper seen through a
lens with u needle. we are sure to thrust
with the needle some distance beyond the
paper, appearances being quite deceptive in
this case.
Simple microscopes, now called t0Hpc$,
ana still of much service to men of science,
gave a great deal of information to those
ancient wisearres who went about the world
with their eyes very wide open, and led
them to suspect that there We're more things
in earth and air and water than were
dreamed of in most philosophers, but it was
not until the compound microscope saw the
light that microscopy as Il science can claim
TO have had an existence
About 1870, toward the end of that Won
,lertul sixteenth century, when the spirit of
invention and discovery seemed fairly to be
let loose upon the restless earth, Zacharias
Jansen, a humble Dutch spectacle grinder
ol -hlttitluure, HTSt thought Vi improving
his magnifying glass for minute objects by
putting the lens. or object glass, ut the end
of Il tube, and ut the other end inserting
another lens, or eye-pece, the idea perhaps
suggested 10 him by the Italian Calico $
new tangled telescopes. In Il microscope
the object glass is smaller than the oculctr,
or eye piece, whereas in telescope the con-
vex lens at the far end is very much the
larger.
AS far as the increase in magnifying
power Went, the new instrument was a
great success, but in all other respects it
was a disappointment. The large images
seen through it We're distorted and ill-,le-
fined, their edges fringed with all the colurs
of the rainbow, and the stronger the glasses
We're made, the more apparent We're these
defects. For Il long time the thing was
nothing more than Il scientific toy Of really
10 practical value, for the makers did not
know how to correct this troublesome chro,
| matte and spherical alteration, as it was
called, which waS owing to the law in OPP
tics that caused the glass lenses TO separate
and distort the rays of light that passed