The Democratic press. [volume] (Ravenna, O. [Ohio]) 1868-1901, 1881-01-13
SCIENTIFIC.

Alum and plaster of Paris. well mixed
in water and used as thick cream,
form a hard composition and also a use
full cement.
DR.. Ernmerick, German physicist,
declares that polluted water does not
injure the health. He purposely drank
a quantity of it himself. and the only
result was that it cured him of a gastric
catarrh.
a recent course of experiments made
shows that one cubic foot of ordinary
sixteen-candle coal gas will develop 318
heat units, while water gas will give
only about 1877 heat units per cubic foot.
The habit of fish to return to the same
place in a river to swarm is well known.
1t is asserted that on going up they keep
their return they take the opposite side.
Fishermen, take advantage of this fact.
Oyster-spawn when thrown off by the
mother soon seeks some clean shell or
gravel on which to fasten or ''set."
This is why new ground for oysters
needs to be covered with clean shells or
stones. Oyster-spawn will not ''set"
on mud or muddy, dirty, or greasy mat
ter, even if on shells. Hence shells are
much in demand for preparing new
ground.
A very successful experiment with a
compressed air locomotive was lately
made in Woolwich, England. The en-
gine was provided with reservoir of
one hundred cubic feet capacity. With
air filling this chamber at one thousand
pounds pressure on starting, a run of
sixteen miles was made at a fair rate OF
speed. So great are the advantages of
the ''bottled air'' for street railways,
tunnels, etc, that an early adoption OF
this class of motors in many Localities
is sanguinely expected.
A new and apparently most valuable
method of preserving raw meat. discov-
cred by Professor Artimini of Florence,
and patented in this country, promises
to haye a great effect. on our markets
According to report By Professors
Barff and Mills of tho Glasgow Univer-
sity, and DIR. Stevenson of Guys Hospi-
tai, meat six months old was found to
be perfectly sound and good, the mus
| cular fibre unchanged. and the nItritive
properties unimpaired. The material
| employed is said to- he less expensive
| than salt, and not only wholesome but
| pleasant to the taste.
For the brilliant white enamel often
applied To cards. etc, the following for
mnla is given in 1.-The Engineer: For
white and for all pale and delicate
shades take twenty-four parts by weight
| Of parratiue and add thereto one hum
dred parts of pure kaolin China clay).
very dry, and reduced TO a fine powder.
| Before mixing with the kaolin the par
affine must be heated to a fusing point.
let the mixture cool, and it will form a
| homogeneous mass, which is to be re-
duced to powder and worked into q
paste in paint-mill with warm water.
This is the enamel ready for applica-
ton. 1t can be tinted according to
fancy.
A very slight declevity suffices to give
the running motion to water. Thres
inches per mile in a smooth, straight
channel gives a velocity of about three
miles an hour. The Ganges, which
! gathers the waters of the Himalaya
mountains, the loftiest in the world, is,
100 miles from its mouth, only 800 feet
above the level of the sea. and to fall
800 feet in its long course the Water re-
| quires more than a month. The great
river Magdalena, in South America,
running for 1000 miles between two
ridges Of the Andes, falls only 500 feet
in all that distance; above the distance
| of 1000 miles it is seen descending in
rapids and cataracts from the noun
tains. The gigantic Rio de la Plata has
SO gentle descent to the ocean tb<t in
Paraguay, 1,50O miles from its mouth,
large ships are seen which have sailed
against the current all the way by the
force of the wind alone-that is to say,
which, on the beautiful inclined plane
of the stream, have been gradually lift
ed by the soft wind, and even against
the current. to an elevation greater than
our loftiest pines.