St. Landry democrat. (Opelousas, La.) 1878-1894, 1883-03-24
SCIENTIFIC MISCELLANY.

Prof. DufOur states, us aii osellooh0u
fact, that hail-preventers of the nature
of lightning-rods were set up I'D seye-
raj VINEYARDS Of the Canton de Vaud IN
1895: the object being to hinder the
formation of hail by Withdrawing cleo
tricity from the clouds. Some OF the
yineyards thus protected were des-
froyed by hail the next year, and the
.s,xperiment was declared a failure.
while doubling the influence OF such
apparatus on hail-clouds, Prof. Dufour
thinks the matter deserving OF fresh
inyesti cation, inasmuch as it has re-
Gently been shown that the presence o1
a forest-which may be regarded as
collection of lightning-rods-may great
sy lessen the frequency of hail-shoW- how
.serS.
When long heating has driven all
air from the water in steam-boller,
boiling sometime ceases, and super
heating may occur with danger OF S ex-
nlosion. Clean pieces of zinc ~ the
aiquid, by uniting with some OF It's oxy-
gen and liberating hydrogen, should
theoretically maintain boiling. As a
anore reliable plan in practice, however,
Mons. Treve advises the injection at
che bottom of the boiler of hot air, or,
still better, of a non -oxidizing gas such
as carbonic acid-the injection to De
snoderate but continuous. Superheat-
Ing. which may be conceived as sleep
of the LIQUID, would thus be rendered
impossible, and rapid evaporation, say
5ng of fuel and freedom from rlsk
gFould be secured.
When tile spectroscope is turned 20
the sky in daylight the presence OF wa
4ery yapor in the atmosphere produces
in the instrument CHARACTERISTIC lines
known as the rain-band. Sangulne
British metereologists expect to oase
weather predictions on observations OF
this band, and the probability that the
spectroscope may be thus used is mat
ter Of much interest.
Some idea Of what is becoming OF the
forests may be had from . consldera-
tinn of the amount Of wood that Is
s,eing used by railroads. A recently
nubished, report shows that IN the
maintenance and repair of French
railways since 1877 more than seven
hundred fine trees must have been usea
daily for sleepers alone and some
r 600 600 cubic feet of timber have been
required yearly for rolling stock. ana
vet the mileage of the railways OF
France is less than one sixth as great az
chat Of the United States.
a female performer in a Partisan cir
ems remains under water two minutes
and ahalt at a time. 10 appreciate
saws Mons. Kerlus, what ls I'm.
plied in passing two minutes and
half without taking breath let anyone
make a small experiment, holding his
breath as long as possible while watch.
sna the second hand of a watch. Few
nersons reach one minute /; the major.
ity are obliged to take breath before
A5 seconds have elapsed. Sponge ane
r,earl fishes seldom remain under watel
two minutes, and voluntary INNER.
sion of more than three minutes hal
never been observed.
Prof. Ludwig, in Germany, has beer
aed by his Investigations to conclude
that, contrary to the assertion OF Son
4,enschein, arsenic may be readily de
fected in the bones after poisoning bJ
4hat substance. He even found the
x,oison in the bones of dog twenty.
seven days after the last of q series o.
doses had been given the animal.
Observations in France by Mons
Rafford show that flies quickly disap'
near from room after the introduction
of castor roll plant (Ricinus coaensu,,is
Dead flies are found near the plant
from which it appears that the leaves
are highly poisonous to these insects
Mons. d'Abbadie reports to the Frenci
Academy that immunity from marsl
feyers is often secured in unhealthy
Ethiopian regions by exposing the ma
ked body to sulphur fumes. In Sicily
the workmen in sulphur mines on Low
ground suffer much less from inter
1uittent fever than che rest Of the pop
nlation while Mon. Fourqu ha'
shown that in Greece once fourishins
town of 10000 inhabitants Zephyria-
has been almost utterly depopulatet
through marsh fever, the decadenc,
having corresponded to gradual re