New-York tribune., 1911-01-29
Microscope Reveal the Life

"nlfier il il be provided with two convex
surfaces, by putTing 1t part way into q
small hole drilled in a thin plate OF metal.
The first compound microscope differed
from the simple microscope In that the
former possessed two convex lenses in such
| relative positions that one magnlfed m
| enlarged image Of Q small near object
| formed by the otheT. It's invention fol
lowed closely upon the invention Of the
! telescope The idea seems To have oc-
, Cured originally 10 Hans Zansz, or to his
soa Zacharias. spectacle makers at Mid
dleburg, IN Holland about 1890 Then for
more than two centuries the compound
microscope of Zansz was little improved; /;
for it was found that all attempts to in
crease. beyond certain point, its power
OF application augmented at the same
| time the chromaiic and spherical aberra-
ton Of its lenses. and these two seemingly
| inevitable effects so blurred the retinal
picture that the gain in magnifcation
of the instrument.
| Spherical and chromatic alteration were
| long the pet bughears of the microscopists.
TIE first term { presses an irregularity or
| confusion i'm tho passage Of the light ravS
through the lens. due 10 slight inperfec-
| tons in tho curves OF its surfaces. Tie
second refers 80 the differing r-frangihlity
or bending OF light OF different colors,
white light consisting. as every one knows,
OF many colors.
And Just here simple explanation may
also be given as TO why different colored
rays are refracted. or bent differently. All
light vibrates. the amplitude of its viera-
tion, or wave length. varying with its
color Yellow light has the longest wave
length; ultraviolet the shortest. Now. the
longer waves in passing through lens
are less bothered-opposed the mole
cules OF the glass than are the shorter
waves and hence the former, travelling
faster through the lens. are less refracted
by it than are the shorter waves. So, In
asmuch as every color in the spectrum
has a different wave length, il follows
from the foregoing principle that every
color is refracted differently.
Perhaps concrete comparison will make
this fact of the more rapid passage of the
longer waves through transparent me-
dunn perfectly clear. Imagine n tall man
and very small boy walking side by side
along a smooth road; they keep together,
But suppose now that they encounter a
ploughed field. In their progress over this
the man, with his long strides. will forge
ahead OF the little boy. who. with his short
legs. must climb up and then down the
miniature hills that the man steps over.
Just so Is the little light wave checked BY
molecules that the big light wave never
touches
Not until the frst half Of the nineteenth
century was way discovered TO correct
the chromatic alteration Of It's 'ob-
)ectives" by combining concave lenses Of
mint with convex lenses Of crown glass.
AND shortly afterward their spherical
aoerration was also done away with by
certain combinations Of convex and con-
cave surfaces OF different curvatures. After
the successful surmounting OF those two
most serious difficulties the Improvement
OF the compound miscroscope was very
RAPID As space would not permit. how
ever even did general interest warrant,