St. Landry democrat., 1882-05-20
SCIENTIFIC MISCELLANY.

SCIENTIFIC MISCELLANY.
A careful examination has convinced
a French chemist that wheat normally
contains copper to the extent Of eight
to ten parts per million.
Colladon long ago noticed incident
lily that distractions in the path of
y sound decidedly lesson the intensity
of the vibrations. These "sound sha-
dOws' are known to be much more dis
tinct in dense medium like water than
in air. Prof. John Leconte has recently
given results of some further expert
ments on the subject, in which he took
advantage of some dynamite blasts
being made under water. He immersed
vertical pile about a foot in dame
ter, at distance of about forty-tive
feet from the explosive cartridge. Bot
ties and glass tubes were shivered by
the conclusion of the explosions when
placed outside the geometrical shadow
of the pile, but protected when within
it. The sharp definition of these sound
shadows has led Prof. LeConte into an
exposition Of the theory of the effects.
Like shadows of light, the distiveness
of the sound shadow should depend on
shortness of wave-length, and the sud-
den defamation OF dynamite muse gen
crate very short and intense wave,
making very sharply defined shadow
whenever an object is met. 1t follows
that less sudden sounds, like the explo-
sion of gunpowder, must produce less
definite shadows.
Prof. Farchild thinks there are rea-
sons for believing that the common
house fly with it's numerous lenses, ca
pable of change OF focus like the human
eye, can avoid the difficulties we en-
counter in microscopes, and may dis
tinctly recognize objects only twenty
milliOnth of an inch in diameter.
A peculiar and newly observed prop
erty of tin is being investigated by a
Moscow scientist. Some tin cans kept
in one of the government buildings dur
ing the cold weather showed blisters,
then holes, and finally fell to powder.
Prof. Foote, of Philadelphia, has a
group of quartz crystals measuring
about four feet by three in superficial
area. A group in the University of Ma
Piles weighs nearly half a ton. A crys
tai at Milan is three and quarter feet
long and five and half in cir
conference, and weigh $40 pounds; and
another crystal, at Paris, is three feet
in diameter and the same in length,
weighing 800 pounds. Fifty tons OF
crystals were discovered in one cavity
at Zinken, more than century ago,
and were sold for $3OO,OO0,OOO.
DR.. Wollaston's observation that GER
tain sounds are inaudible to many ears
was recently illustrated by Prof. Tyn-
dali. During the lecture he blew a
whistle, the low, shrill note of which
instantly agitated the sensitive flame,
while full half of the audience failed to
hear the sound.
Insects. caterpillars and Larvae are
not destroyed-as is often believed-by
exposure to a temperature Of eleven de-
grees below zero the common CATER
pillar has revived on the return OF suf-
ticient warmth.
The path of destruction Of American
tonadoes has averaged 1,0085 feet in
in width, according to sergeant Finley.
The storm cloud moves at the rate OF
twelve to sixty miles an honr, while the
wind within the vortex sometimes
reaches the tremendous velocity OF
eight hundred miles an hour-392 miles
being the average.
In concluding a course of lectures up
on the ancient World and the APP
pearance Of Man." Prof. Boyd Daw-
kins said that study of the past had
shown that continued struggles with ma
til he had reached his present condi-
ton and it was his belief that in COM
ing ages man would be elevated as far
above the level of culture of to-day as
we are advanced from the state OF saw
apery of the Drimeyal man.
The theoretic work obtained from the
consumption of an ounce of various
substances thus stated by Prof. Sylvia
nus Thompson. One ounce of hydro
gen gives 2,925,0 900 foot pounds; of coal,
$4,000 otpounds zinc, 10000 pounds;
gunpowder, 100000 foot pounds and
copper, $4,000 thousand foot pounds.
A French journal recommends a fire
test sor determining the quality of seeds.
Samples arc placed one at a time upon
live Goals. IF the combustion is slow and
quiet, it may be safely decided that the
seed contained diseased germ but if
the seed turns and leaps about, pro-
ducing dry sound, it may be inferred
to have good germinative qualities.
The good quality of larger seeds such
as acorns and chestnuts, will be indi-
Gated by denotation Of the seed soon
after being thrown into the fire.
The frog, toad, salamander, newt, ETC.,
are found to secrete special poisons.
From the CLANS on the neck Of frog
NJ. Paul Bert has obtained liquid
which caused the death Of sparrow to
which it was administered.
A transparent leather, said to possess
great strength, is now made in Ger
many by new process.
That lady, married or single, who has
become irregular each month, who is
n,ofaI xx,ha is