The Baltimore County union. [volume] (Towsontown, Md.) 1865-1909, 1902-03-22
Correspondence Baltimore County Union.
SCIENTIFIC MIS- CELLANY.

Correspondence Baltimore County Union.
SCIENTIFIC MIS- CELLANY.
Sound Failures--The Atmosphere's Cold
Chemical Weeding-Speaking Pictures
-Celulose Hair--A Surgical Warning
-Calmettes Snake-Bite Specifc-An
Alarm for Ships-Comfort for Ocean
Tourists.
About sound we have much to learn. De-
scribing some late trials of horns, Lord Ray
leigh stated that those having elliptical instead
of circular cones best spread the sound hori-
zontally 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 mystery. 1t
has been thought to be due to interference be-
tween waves of sound reaching the spot direct
and thus reflected by the sea. but failure to re-
cover the sound by climbing tall mast throws
doubt on the theory. One fog-horn at station
may be better than several. as two or more
sounds may tend to neutralize one another.
Air soundings of the last few years have given
very unexpected temperature results. The up
per air is colder than was supposed, the average
being about 13o below zero f. at 10000 feet and
$50 below at 5000 feet; and the decrease of
temperature gains in rate instead of becoming
slower as the altitude increases. The fall of 80
for each LOCO feet in the lower strata becomes
nearly twice as much at the greatest height
reached. The influence of seasons at high alti-
tudes is surprisingly great, and at 10000 feet
the average March temperature is about 60 be-
low zero, while that of August is only Az below.
s*s
The chemical destruction of weeds is advo-
Gated by learned French horticulturists. One
application of mineral oil and water keeps down
the grass in walks for two years. sea-salt kills
thistles, and spray of sulphate of iron is eff
fective against injurious plants Of all kinds.
~
Porcelain violins and mandolins, shaped ex-
actly like the wooden ones. are claimed to have
greatly improved tones. Their weight and IL
ability to breakage are disadvantages
sc
Moving pictures OF the electric arc have given
RUNNER, a German experimenter, some inter
esting results. In the circuit were placed
an induction coil and microphone. with liquid
interruptor to be used as desired and slit in
front of the horizontal arc caused the image of
the two carbons to fall upon the ground glass of
the kinematograph. The moving Photographic
film recorded the steady arc as a bright. con-
tinuous 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. Be-
fore talking into the arc, the image was reduced
by lens to fine point upon the film, which
was moved ten feet 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 a sensitive
selenium cell. The varying brightness of the
picture varied the electric resistance of the
unIo amin ofpn
through it that two telephones in the circuit re-
produced the speech with surprising clearness.
Artificial hair has been difficult material to
make. Cocoanut and agave fibers have been
much used for stuffing furniture, and chemi-
cal treatment is claimed to make them imper-
Yious to wet. odorless elastic, unreliable and
unbreakable. But their short length limits
their use in fabrics. The success of silk from
cellulose has led some manufacturers at Frank
fort-on-tbe-Main to make further trials. with
the same substance, and they seem to have pro-
duced not only a very satisfactory imitation
horse hair but very good substitute for hui
man hair for wigs. Brittleness of the cellulose
the troublesome difficulty, was overcome by
spinning several threads together.
-
Carbolic acid as dressing for wounds seems
to be attended by risk little understood Dr. J.
G.. Sheldon reports recent amputation of the
leg made necessary by splitting weak carbolic So
luton on the foot, and a Massachusetts, physi-
clan some years ago found records of more than
100 cases of gangrene due to free use of car
bolic acid much diluted for slight wounds and
bruises.
In his ten years of experiment at Paris and
Lille, DIR. Calmette has made his autonomous
serum an effective remedy for snake-bites
when injected within four or five hours and it
is now supplied to such countries as India Aus
tralia and tropical South America, where the
victims number tens of thousands yearly The
preparation of this antidote requires the venom
of many serpents. Cobras and others are kept
alike in a special hot-house. and once fort
night the doctor and an assistant extract the
venom from each by holding its head in the
hands and COMPRISING the poison glands. The
snake, which seldom eats in captivity, is then
forcibly fed by pouring two or three raw eggs
through glass funnel into the stomach The
poison, dried for keeping, is used in solution
for inocuating horses or dogs, and at the end of
sixteen months horse is made capable of re-
ceiving safely dose that would kill 200 nnvac-
cinated 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 Sjostrand, Swedish in
ventor, is novel shoal-water Indicator, con-
sisting of an aluminium plate, held by two wires,
and 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.
20
A long and vigorous breath at frequent inter
walls is the preventive of sea-sickness that Prof.
Heinz, of Erlingen, regards as infallible as sim
pie. The explanation is that the extra oxygen
added to the blood lessons the sensitiveness of
the brain that produces a-sickness by react
ing on the stomach.
Such quantities of shingle are being deposit
ted by the sea at Dungeness, on the English
Channel that in sixty years lighthouse has
been left half mile inland.
Mrs. MARY P. FREEMAN