Staunton spectator. [volume] (Staunton, Va.) 1849-1896, 1886-04-07
SCIENTIFIC MISCELLANY.
lCompiled for the SPECTATOR. ]

PERCEPTION OF COLORS.-SensatlOns OF
vision require definite time of exposure of
the retina, which time Mr.. j. NJ. Cattell, of
the University of Lepsic, finds to be con-
siderably dependent on the nature of the
object and the intensity of the light. 1t
varies with the several colors. Orange gives
the quickest impression on the eye, and yell
low closely follows it; then come blue, red,
and green, while the retina is least sensitive
to violet light, the time for which is from
two to three times as long as for orange
By lamp-light the eye works more slowly
than by daylight, and the order of perceiv-
ing colors is changed to orange, red, gel
low, violet and blue.
AN OVERLOOKED MATERIAL.-A German
writer remarks that the compound known
as ''zeiodelite," discovered by Simon, has
not been used SO much as its peculiar ad
vantages would seem to suggest. 1t is pre-
pared by mixing % to 80 parts of powdered
glass with &c parts of melted sulphur. This
may be shaped into any design; and it cools
into stony hardness, resisting boiling
water and the strongest acids. 1t can be
united at heat of 400 degrees.
A workshop of the stone age has been
discovered near the gates of Paris, and has
3 yielded nearly 900 hand. worked flints, in
Guiding pieces of polished hatcbets, scrapers,
blades, points, and two or three little polish
ers.
An electric-light dynamo in London is
driven by a steam engine which is said to
make IL, 600 revolutions per minute, and is
claimed to be the first motor ever made to
work at the actual velocity of the steam as
it escapes from the boiler.
A spiny African caterpillar, seven inches
long and of steel gray color, was exhibited
at recent meeting of the Linnean Society
of London.
RESULTS OF ENGLISH SANITATIoN.-Im-
proved health laws appear to have produced
remarkable results in England and Wales,
a decided reduction in the death rate having
now been maintained for ten years and been
much greater during the second half of that
period than in the first. So great has been
the recent reduction that, as the registrar
general points out, more than 281, 900 per-
sons survived the last five years whose
deaths would have been recorded had the
mean rate of morality been equal to that
prevailing in the ten years 1S71-S0. The
effect on longevity has been indicated by
Mr.. Noel Humphrey, who states that the
reduction in the death-rate from 22.5 in
183854 to 90 s in 1076-90 has added two
years to the life of every male born, and
three years and a half to that of every fe-
male.
INSECT sMELL.-In an extensive series OF
experiments by Prof. GRADER, insects and
many other invertebrates perceived odors
much more quickly and acutely than the
vertebrates tested (birds and reptiles The
antennae proved to be not the only organs
of smell in insects, although these appear to
be essential to the perception of some fine
odors. In some cases the palpi of the mouth
organs are more sensitive than the auten-
nae, but perception Of smell through the
stigmate or respiratory organs is not rapid
nor important
Penkert has determined that in the Swan
electric lamp the proportion of the energy
transformed solely into light is 2S1 per
cent; in the Siemens, 27.9; in the Edison,
265; and in the arc lamp, 1873.
Instantaneous photographs of the hearts
and intestnes of various animals have en-
abled DR.. W. G. Thompson to determine
the action of the organs more clearly and
accurately than is possible by other methods.
Such photographs may prove of great value
in showing changes effected by drugs, as
well as i'll their physiological teachings.
AN INTERESTING PET-The Beaked
Chaetodon of the Indian and Polynesian
seas is fish of eccentric form and beauti-
full tints, but its most remarkable feature
is its curiously elongated muzzle or beak,
which is employed as gun, with drop of
water for a bullet. Unlike other fishes,
this creature does not wait for its prey to
fall into the water, but shoots it down like
a true sportsman. Seeing fly or other in
>sect on twig over the water, the Chaeto-
dan quietly approaches and, with its nose
iust>above the surface, accurately projects
a dro1>Qf water at the unsuspecting insect,
which is thus knocked from its perch and
is quickly snapped up by the fish. The
finny archer is highly priced as household
pet by the japanese, who keep it in bowls
and amuse themselves by watching it
"shoot" flies held up before it.
WORK OF oBsBRvAToRlEs.-Pro in
astronomy no longer depends upon chance
observation, but is now effected by divi-
sion of labor and concentration st certain
points upon some one particular object of
research. The leading observatories>> all
work at specialties. At Harvard the reia,
tive magnitude of the stars receives chief
attention; at Princeton, spectroscopy; at
Allegheny Observatory, the dark part of
the solar spectrum and the effect of the in
visible heat rays on the earth; at the Ma
tional Observatory, positions and orbits of
satellites; at Cincinnati, double stars: at
Chicago, the surface of Jupiter; and at
Albany and Yale, the perfecting of maps of
the heavens
German chemist Prof. G. Winkler,
has discovered a new element-"Germani-
um"-in mineral named Argyrodite
which consists chiefly of sulphur, silver and
mercury.
Primrose seeds from height of II, 900 to
$4,000 feet in the Himalayas have been re-
ceived at Calcutta, and some are co be
planted in England.