The Saint Paul globe., 1902-02-25
SCIENTIFIC MISCELLANY.

SCIENTIFIC MISCELLANY.
About sound we have much to learn.
Describing some late trials Of fog horns,
Lord Rayleigh stated that those having
elliptical instead of circular cones best
spread the sound horizontally when the
long aXis-Which was four times the
length of the shorter-Was vertical The
anomaly of the silent zone, on both sides
of which the sound is heard, is still a
mystery. 1t has been thought to be due
to interference between waves Of sound
reaching the spot direct and those re-
fected by the sea, but failure to recover
the sound by climbing a tall mast throws
doubt on the theory. One fog-horn at a
station may be better than several, as
two or more sounds may tend to neu-
tralize one another.
Air soundings of the last few years have
given very unexpected temperature re-
suits. The upper air is colder than was
supposed the average being about IS
degrees below zero +. at 20,0O0 feet and
So degrees below at 25,000 feet; and the
decrease of temperature gains in
late instead of becoming slower
as the altitude increases. The
fall OF degrees for each LOCO
feet in the lower strata becomes
nearly twice as much at the greatest
4AOlo4AI AOoCiISu 1 IlS 1llHQGICS VI S6dSO1lS
at high attitudes IS surprisingly great,
and at $4,000 feet the average March tenn
perature is about 65 degrees below zero,
While that of August is only A degrees
below.
The chemical destruction of weeds is
advocated by learned French horticulture
lists. One application of mineral Oil and
water keeps down the grass in walks for
two years, sea salt kills thistles, and a
Of 4I,,1,- r. 0f to offr
against injurious plants Of all kinds.
Porcelain vioIins and mandolins, shaped
exactly like the wooden ones, are claimed
to have greatly improved tones. Their
weight and liability to breakage are dis
advantages.
Moving pictures of the electric arc have
given Ruhmer a German experimenter
some interesting results. In the arc cir
cult were placed an induction coil and a
microphone, with a liquid interrupter to
be used as desired; and a slit in front of
the horizontal arc caused the image of
the two carbons to fall upon the ground
glass of the acknowledgement. The moving
Photographic film recorded the steady are
as a bright, continuous band. When the
arc missed the band became WaVy, the
liquid interrupter cut it into rectangles
of varying lengths, and whistling caused
hundreds of vibrations to appear. Before
talking into the arc, the image was re-
Guced by a lens to a fine point upon the
film, which was moved ten feet a second.
After the speech photograph was taken,
the film was again passed through the
camera box at the same. rate, and the
picture was thrown by the arc upon
sensitive Selenium cell. The varying
brightness of the picture varied the cleo
trio resistance of the seleniUm, SO af-
fecting the current passing through it
that two telephones in the circuit repro
duced the speech with surprising clear
ness.
Artificial hair has been a difficult ma
to ixo
have been much used for stufiing fur
nlture, and chemical treatment is claim
ed to make them imperViouS to wet odor-
less, elastic, unreliable and unbeatable.
But their short length limits their use
In fabrics. The success of silk from cell
lulose has led some manufacturers at
Frankfort ont Main to make further
trials with the same substance, and they
seem to have produced not only a very
satisfactory imitation horse hair, but a
very good substitute for human hair for
wigs. Brittleness of the celiulose, the
Troublesome difficulty, was overcome by
spinning several threads together.
Carbolic acid as a dressing for wounds
seems to be attended by risk llttle un-
derstood. DR.. J. G. Sheldon rep .rts a
recent amputation of the leg, made nee
eSSary by spilling weak carbolic solutiJ IN
on the foot, and Massachusetts, physi-
clan, some years ago. found records Of
more than 100 cases of gangrene due to
the free use of earbolic acid much dilut-
ed for slight wounds and bruises.
In his ten years of experiment at Paris
and Lille, DR.. Calnette has made his
antivenomous serum an effective remedy
for snake bites when injected within
four or five hours; and it is now supplied
to such countries as India, Australia and
tropical South America. where the VIC
tins number tens of thousands yearly
The preparation of this antidote requires
the venom of many Serpents. Cobras
and others are kept alive in a special
hot house, and once a fortnight the doc
tor and an assistant extract the venom
from each by holding it's head in the
hands and compreSsing the poison glands.
The snake, which seldom eats in captiv-
ity, is then forcibly fed by pouring two
or three raw eggs through a glass funnel
into the stomach The poison, dried for
keeping, is used in solution for inocufat-
ing horses or dogs, and at the end of six
teen months a horse is made capable of
receiving safely a dose that would kill
200 unyaccinat ted horses. From each horse
may then be taken every two or three
weeks from six to eight quarts of blood
containing two or three quarts of active
serum. The serum is bottled in single
doses-abOut third of an ounce.
The water kite of Sjorstrand. a SWe-
dish inventor, IS a novel shoaI-Water IN
dicator consisting of an aluminium plate
held by two wires, and is so balanced by
weights as to swim beneath the vessel at
a practically uniform depth with speeds
of five to fifteen knots. If an obstacle is
struck, one wire is detached, causing an
alarm bell to ring.
A long and vigorous breath at freqeutn
intervals is the preventive of sea sick
ness that Prof. Heinz, of Erlingen re-
CARDS as infallible as simple The ex-
planatien is that the extra oxygen added
to the blood lessons the sensitiveness of
the lobe of the brain that produces sea-
sickness by reacting on the Stomach
Such quantities of Single are being de-
posted by the sea at Dungeness on the
1English channel, that in sixty years a
| lighthouse has been left half a mile in
| land