The daily Cairo bulletin. (Cairo, Ill.) 1878-1???, 1881-03-17
SCIENTIFIC.

The tea plants grown by Count
d'Amigo on his estate near Messina, pro-
duce leaves which are said TO be rs good
MS those of the plants raised in China.
There is to be n systematic attempt now
made TO grow the tea on n commercial
scale.
A Mr.. St George Lane Fox has been
working on an electric lamp on the
same principle rs Mr.. Edison's, and it
would seem from a report OF private
exhibition of the efficiency of this lamp
that Mr.. Fox has been very successful.
The tests were made, at the Office of the
British Electric Light company, Lon
don. 1t is claimed that the Fox in
candescent lamp will last for years if
subjected "to ordinary average use"
The largest torpedo-boat in existence
has lately been launched at Copen-
hagen, She is called the Nordenskjold,
and measures 2l5 feet in length and AZ
feet in breadth. Her displacement is
estimated at 200 tons With engines
OF 2,500-horse power, it is expected she
will sail at the rate of fifteen miles an
hour. Her armor is of steel, and is
four inches thick. She is to carry the
heaviest breech-loading Krupp gun ever
borne by any ship of war in the Baltic.
A material which has been proposed
Tor the fltering and decolorizing of
sugar and other substances consists of
d led or baked graduated clay mixed
with blood in the proportion of three
parts of clay to four of blood Some
times vegetable charcoal is added. The
mixture is nodded into Jumps of any con-
venient form, dlied, broken into small
pieces, mixed with an equal bulk of
graduated clay and after having been
carbonized in q retort, carefully
screened. The screenings are said to
answer admirably the purpose for which
they are designed.
Some French physicists contend that
the musical notes produced by Prof.
Bell in disks of mica, india-rubber,
metal, and wood, by holding them in
the path of rapidly interrupted beam
of light, are really due TO heat and not
to light. Even plate of copper heated
to bright red produced very distinct
musical notes, which died gradually
away as the plate cooled To a dull red.
Disks coated with silver on the side en-
posed to the ray gave very feeble sounds,
but when coated with lamp-black the
sounds were strong.
Mr. Covers form of the Bell tele-
phone has been adopted by the British
postoilice authorities. who have given
an order for twenty thousand of the in
struments. 1t has been tried on the
Southwestern railway, England, with
much satisfaction in communicating
with the signal cabins on different sec
tons of the line, The telephones were
simply connected between the existing
wire for working the block" system
and the "earth." Conversation was
then distinctly carried on without inter-
fering in the least with the ordinary
signals 1t was interesting to hear
through the telephone the sound of the
train itself leaving the distant station at
the same time as the strokes of the sig
nal bell announced the departure.
An interesting analysis of the various
modes of sensiblity of the visual APP
paratus, the London Times reports, has
been made by Mr.. Chambers. He has
been experimenting by looking in dark
ness at an Opaque screen in which was
perforated three or four minute holes,
quite near each other, but distinguishes
bic when medium light shone through.
Light was raised from zero on the other
side; ii was sometimes Colored. The
order Of phenomena was proved to be
this: The first action of light entering
the eye in very small quantity is in all
cases merely to produce difuse lumn-
GUS sensation not differentiated either
rs to color or As to form; with agreater
quantity one gets the notion OF color,
ii there be color in the light; and still
more light is required to he able to
resolve the luminous object into its
different elements. Luminous sensible
ity is the most simple reaction; then
comes chromatc sensiblity, by which
we distinguish color, and lastly, what
the author terms visual sensibility, by
which we distinguish form.