The workingman's advocate. [volume] (Chicago [Ill.]) 1864-1877, 1868-04-11
Scientific.

A NEw UsE FOR NAPTHALINE.-It has re-
rently been asceI tanned that a very small
quantity Of napthaline placed on rev
plant viii keep away insects injurious to
them, without affecting the plant itself
Should this b. the case . degree greater
than by ihc use Of its ally, benzine, We have
an indication of application of napthaline
for preserving biological collections, as well
as living plants Of much Importance.
ACQUIRED Gardener, in bis emusic of
Nature" asserts thai dogs in a state Of ma
ture never bark they simply whine. howl
and grow. The Australian dog never barks,
and Columbus found that the dogs he had
previously carried to America had lost their
propensity for barking. This peculiar ex-
rlosive seems to be an acquired faculty,
ubich the animal derives from bis assoeia-
ton with man.
BEwAgs ~ BENzISE.-From the facility
with which ii removes grease spots from
fabrics, this substance has come to be re-
earded almost az household indisper sable.
Bnt few persons, however, realize the explo-
., character Of benzine or tine dangers at
tending the careless handling Of the liquid.
Berg one Of the most volatile and infam-
mable products resulting from the distil-
lation Of petroleum, it yaporlzes with great
rapiditv, 90 that the contents OF iour-ounce
vial, il overturned, would render the air Of
moderate sized room highly explosive
The greatest care should be exercised in
handling this substance, 10 proximity to FIRE,
and it is important TO remember that the
vapor escaping from an uncorked bottle will
cause q fame TO leap over space OF several
feet.
Nrw ELECTRICAL BArrERIEs.-M BaIsamo
has presented to the French Academy bat
terry, both elements Of which consist Of IRON,
the ore being immersed in solution Of
chloride Of calcium, the other in diluted sui
phuric acid, the two solutions being seysra-
ted by a porous cell. The iron in the sui
phuric acid acted as the positive clement.
aud the other as negative. A constant and
quite an intense current is obtained by this
arrangement. Another novel battery, term
ed an Gelectric buoy" is nov being expert
mented upon at CherbouTg. Ii consists Of q
zinc plate and q cTlinder Of carbon, attach
ed to cross piece Of wood, having sea
water as . exciting liquid. Still another
variety is that Of NJ. Mlergue, of Bonfsrik,
consisting Of cylindrical cell Of porous
carbo-, containing nitic acid, and 40 ex-
terror cylinder Of amalga mated zinc in cell
full Of water.
MAMMOTH GLASS Piazza single plate Of
glass has just been impo ted from France
twenty feet long by sixteen feet eight inches
vide. 1t is used not az a window, but to
represent, under strong light, frozen lake
in a theatrical scene, where the professional
fairies have made q new sensation by dis
playing the "poetry Of motion" on glistening
lee. A natural inquiry is, how such brittle
material as glass can be cast and annealed
10 this extent; why it should not Fly in pieces
under the unequal changes Of temperature
to which portions OF it are nightly subjected.
The glass is made Of such thickness as to
resist a very powerful blow; but the effect
Of unequal beating, which often cracks iron
plates as well Is glass, ia not 90 great as
might be supposed; the number OF feet upon
il at one time does not exceed dozen, and
they are not there long enough to produce
any perceptible change in the temperature
OF the glass. There is secret connected
with the manufacture of large glass plates
known only in certain factories in France.
Il is, comparatively speaking, an easy task
to make plates Of enormous size. but 10 pro-
duce them free from cloudy spots, or, In
other words, perfectly transparent and
Homogeneous throughout has required
much time and many experiments; the sur
mounting Of difficulties yet encountered In
other countries where glass Is still too brit
tie, il probably the result Of expert manipu-
lation, IS well ~ the addition Of new inEre-
dients.