The star. (Reynoldsville, Pa.) 1892-1946, 1903-05-20

Acurdingl TO Sir William Thistle
tonDyer. diIector Of Kew Gardens.
some ezpctimentS undertaken It
Chelsea, q 4uburb Of London, during
fog went y prove that in one week
no less than vsix tons Of deposit to the
square mile IEere deposited. Not only
did this conSist Of SCOT, but a consid-
cradle variety Of tarry hydrocarbons
were also deposited. which had very
injurious effdcts upon plant and ami.
NAL life.
Professor bngley of the Smithson-
ian institution has discovered by ex-
pertinent tha II tho air in long
telescope be a(eitated perfectly quiet
image of sdar or Of any other OBJ
ject may be obtained. Astronomers
have been bothered by the unsteadi-
ness of the air ever since the tele-
scope was invented. and for that rea-
son observatories have been built on
elevated ground wherever practicable.
The result obtained by Professor
Langley may bd due to the fact that
the agitation on the air inside the
telescope Offsets the unsteadiness Of
the outer air. $hd thus equalizes the
conditions.
A paper pointing out the many i'm
perfections of Photographic shutters
was read beforeI the American Society
for the Advancement Of Science at its
recent meetingl Investigation has
shown that the better grade Of shut
tiers are fairly constant in operation.
but the actual duration of exposure
is often not oven approximately that
indicated by tho maker Different
shutters Of the same make and form
give different exposures when set for
the same time. Some of the cheaper
makes, designed to give long. medium
and short exposures, give equal ex.
posures in the three cases. All this
may account for the difficulties that
many amateurs haye In their work.
-4
Objects too small or distant to be
seen-like fixed stars--are made per-
ceptible by their light. Taking advan-
tage Of this fact. Sfehentopf and Zsig-
mondy have magniheh strongly illum-
mated particles, and IN this way have
made visible the dif4raction discs of
specks of matter approaching mole.
cules In minuteness. I Their observa-
tions were made urtpn particles Of
gold embedded in ruv " glass. From
the known quantity Il gold and tho
number Of discs, 1t wak calculated that
each particle, with an apparent diam
eter of 50,000th OF e millimeter, and
1t was further shown at the limit of
magnifcation would be 100000 dame
ters. The greatest powers of this
method would show a particle having
10 times the diameter bf a molecule.
In the body changer IS hat take place
RS we grow old, Metc bnkoff and other
psychologists suppos E that an i'm
portant part Is takeiI ~ the phago-
cytes, or devouring cvelb. Some years
ago 1t was made to ayppsar that some
of these cells are cdlo, eaters, and
that they whiten the Ihair by seizing
the pigment grains land conveying
them into the skin or dut of the organ
ism. On further study the theory has
been evolved that old age itself is due
to phagocytes that destroy the nerve
cells. The nerve-eatihg( cells have
been found in the brains ,of many old
people and old mammals Rs well as in
persons suffering from nervous dis
ease, but in no case have they been
known to reach such devdlopment--or
to have so nearly taken the place Of
the nerve vells-as in tho brain of a
parroquet that died at THE great age
of 81, after some years or feebleness
and senility.