Savannah morning news. [volume] (Savannah) 1868-1887, 1884-11-30
BITS OF SCIENCE.

Water filtered through porous unglazed
| porcelain is absolutely free from micrObia.
| With a single such vessel, 0.20 metre long
| by OBS metre in diameter, Mr.. c. Cham
| berland obtained about 20 litres a day of
| physiologically pure water.
NJ. POIncaire contends that the attrac-
! tiOn of the moon mOdifes the intensity of
| gravitation. Hence at the equator the
| clock is retarded by half a second yearly
by the combined attraction of the sun
| and moon, and advanced a second at the
poles.
Experiments with the albumenized pa
per OF photographers show that light can
not penetrate water to a depth exceeding
| some 800 feet; traces of light were dis
tinctly lett on the plates at this depth, but
the plates employed were required to be
very sensitive.
In the Province of Viatka, Russia, there
are produced annually 100000 pounds
of tar, 5, 400, 900 pounds of pitch and 2160,-
600 pounds of turpentine oil. 1t is stated
that the annual product of birch oil
amounts to 144,000,000 pounds 100000
pools }, an indication that the demand for
it is now great.
A system of rails for street railways, in
troduced by NJ. Marsillon, is under trial
by the COmpagnie DIES Omnibus. of Paris.
1t consists of an ordinary bridge rail and
counter rail of the same section bOlted to
an iron longitudinal sleeper. The absence
of wood makes the system very durable
one, but it is very inelastic.
AS to the depth reached in sounding the
ocean, Lieut.. Bergman obtained bottom
at 1850 fathOms short distance south of
the Banks of Newfoundland. The depth
of the sea is commonly exaggerated. PeO-
pie used to think that it ranged from 1000
to 5000 fathoms. The average depth is
$500 fathOms in both the Atlantic and the
Pacific.
Cast iron if heated for several days to
about 900 to 1000 degrees neither melts
nor softens, but is converted into mallea-
Bile iron. Its surface is covered with a
grayIsh efiiorescence. The fracture is
sometimes of a uniform black, like that of
a lead pencil, and sometimes riddled with
large black points regularly distributed in
the metallic paste.
Until lately most of the supply Of sugar
in Denmark was imported. Now the ma
terial for sugar is provided within the
boundaries of the kingdom. Six years
ago the Danes made 100000 pounds OF
beet-rOOt sugar, and four years later the
figures rose to 100000 pounds. The pro-
ductIon of 1882 exceeded that Of 1881 by
fully 100000 pounds.
The effects of the inhalation of fumes of
strong ammonia on the system are deaf
ness and catarrh. In some instances the
troubles are very serious indeed. 1t will
induce lung disease if there is any ten
dency to weakness of the lungs. The most
valuable remedy is to inhale the fumes of
strong glacial acetic acid which reacts
upon the alkali ammonia.
Lead tanks which withstood sulphuric
acid perfectly, Mr.. S. p. Sharples reports,
were soon destroyed by hydrochloric acid.
In some recent experiments undertaken
to destroy cotton fibre by means of hot
hydrOchloric acid it was found that lead
lined vessels were soon rendered useless
! by it. Even the cold acid could not be
kept in wooden tanks lined with lead.
The skin or outer cover of the insect con-
sists of the cuticle, not comparable with
any part of the skin of a vertebrate and
underlying tissues. The cuticle consists
Of two very distinct layers-one thick and
transparent, the other, in which also pig
ment is developed, thin and Opaque. The
pigment is disposed in beautiful micro
scopic markings, differing in different
species.