The Donaldsonville chief. [volume] (Donaldsonville, La.) 1871-current, 1882-07-29
SCIENTIFIC MISCELLANY.

by the waters of the ocean is rouehl,
estimated at two million tons.
Transitory color blindness has beer
produced by few hours stay in snow
fields Illuminated by the sun, all artificial
lights appearing green for short time.
1t has been estimated that there are
about 6OOO species Of birds, of which
tive-sixths are known. The Cones list o1
North American birds now embraces 88e
species, 12O new species having been
added during the last eight years.
Before an English committee of inquiry,
DR.. John Hopkinson has expressed the
belief that the whole of the electricity
generated by one horsepower would not
do more than boil a gallon and half of
water an hour. This opinion was given
as evidence that electricity is not likely
to ever become economically useful for
heating purposes.
The electrical exhibition soon to be
held at Munich will be Of especial in
terest, as it is proposed to use the 5000
horsepower Of the river Isar to drive the
dynamo-electric machines, and to show
the possibility of employing it to light
streets and houses at distance of some
miles as well as to distribute the force to
the various workshops.
The total amount of gold in the aurif.
erous sand of the Rhine has been
estimated at $50, 900, 900 but it is mostly
covered by soil under cultivation. The
richest portions of this sand contain only
about one part of gold in two millions,
yet sands have been worked when con-
tanning much smaller proportion. Gold
in small quantities also occurs in the
sands Of the Rhone, the Aar, the Danube
aud several other European rivers.
The annual report of the Greenwich
Observatory for 1881 calls attention TO a
remarkable change in the motion of
Sirius, the dog star. During 1877 and
1873 this star was travelling through
space at the rate Of about TWENTY-FIVE
miles second, but last year this rate
seems to have been diminished to about
seven miles o second. This apparent
decrease of speed is supposed to he due
to the movement of Sirius, in its orbit.
A curious fact in connection with
instantaneous photography has lately
been noticed. In the photography of a
vehicle drawn by trotting horse, all
the parts are very distinctly shown
except the wheels, which are less dis
tinct in their upper part than in the
lower. The reason is the mathematical
one that the spokes of the wheel have a
much greater velocity when at the upper
part than when their extremities are
near the ground.
A prize of $4,000 has been offered by
the French Government for the most
useful application of voltaic electricity
made during the five years ending July
l, 1877, the competition to be open to all
persons. Several of these So called
:" Volta prizes" have at different times
been awarded, the first having been
offered by Napoleon just after Volta
invented his celebrated "pils." The last |
award was made to Prof. A. Graham Bell |
in recognition of his telephone achieve
ments.
Prof. William Ramsay suggests that |
the vibration theory be applied to ac-
count for the sense of smell, as he deems
it probable that smell is excited by
Of a lower period than those |
which give rise to the sense of light or /
heat. These vibrations are conveyed to
The network Of nerves in the nasal cavity
by gaseous molecules from the substance
giving the odor. The difference of smells
s caused by the nature and rate of such
just as difference in tone of
musical sounds depends on the natnre
and rate of vibrations.
One of the objections urged against
the proposed tunnel across the English
Channel is that it would open highway
for the invasion of Great Britain in case
If war with Continental powers. DR..
siemens suggests novel plan of defense
rom such invasion should the tunnel be
constructed. He would arrange chambers
If chalk, in communication with the
hore ends of the tunnel, in such a man.
Ter that the chalk might be readily
looded with dilute muriatic acid. The
esult of turning on the acid would be
he rapid filing of half mile or more of
he tunnel with carbonic acid gas,
through which no human beings could
,ass alive.
DR.. Berenger-F6raud has described a
curious people-the itinerant musicians
Who travel in every part of Central
africa, from the Atlantic to the Indian
ocean. They are known as Griots, and
constitute distinct confederation, under
he authority of a chief, whose influence
8 very powerful among it's scattered
members, and who leyies u heavy tax
rom their general receipts. They are
'egarded with fear and repugnanoe by
;he Negro natives of the lands which
hey traverse, and are looked upon as
of an impure caste, whose dead
ire capable of bringing sterility aud
perpetual drought to the ground in
which they are buried. They are skillfnl
n improvising and reciting some play
,ha vinlin and Onitar whilo nfhora HAT |