Chicago eagle. [volume] (Chicago, Ill.) 1889-19??, 1893-01-21
POPULAR SCIENCE NOTES.

August, 1885. and has been an object of
study by NJ. Valiant. This is a south
American boa Boa mHrilbtSl. at least
20 feet long. Up to the end of 1891
the serpent had taken food in this place
81 times, an average of five times wear.
the interval between its meals ranging
from IS to POI DAYS. 1t calls for its
meals by characteristic uncasiness. Its
usual food has been small goats. with
| rabbits on three occasions and goose on
one, and the largest animal it has swal-
lowed has been Kid of Is pounds, or
about one-tenth of its own weight Such
prey is not OF remarkable size. as ser
| penis are capable of swallowing animals
nearly as large as themselves. A few
years age, indeed, horned viper was
caught in the act of swallowing French
viper little larger than itself. and no
Ill effects followed this enormous meal
POSSIBILITIES OF SUGGESTION -
Hypnotism formed subject of con
siderable Importance at the late Congress
of Psychology in London Aside from
Its scientific interest, it was shown to
have practical bearing upon criminal
aifairS-aS in crime believed to have been
committed under the influence of hypnotic
uggestion-and upon medicine and edu-
cation. The case was described of
woman who had been afflicted with a
suicidal mania for eleven months, which
was cured by suggestion during hypnotic
sleep. DR.. Bcrillou mentioned educational
applications. In experiments upon ESQ
children of both sexes. he had found
that eight out Of ten children from six
to fifteen years old could be put into
profound sleep, the ones most susceptible
being. contrary to general belief. those
most free from hereditary nervous de
fects. In these subjects it is easy to
obtain automatic accomplishment of acts
suggested during sleep This has been
verified by many authors, and advantage
has been taken of it to treat habits of
nervousness, filthincss and immortality
that concern pcdagogics as much as
medicine. Suggestion also offers means
of Analysing the different Intellectual
faculties of children
The OPTICAL THEATRE. Apparatus
for combining pictures of successive
phases Of action to produce a moving
figure have been mostly limited to the
representation of a single motion or very
simple action. A French optician. NJ.
Reynaud, has greatly extended the idea.
He has devised q so-callcd optical
theatre, the object of which is to repro
duce a large series of actions, even
whole scene lasting fifteen or twenty
minutes, by the use Of very long band
carrying great number of poses. The
pictures are enlarged by lantern proicc
ton. To give the illusion Of life, the
posturcs must succeed each other without
any extinction or eclipse between and
this has not been before attained bv any
projection apparatus The construction
of the optical theatre provides that the
succession Of the postures may be inter
rupted at every instant without causing
the disappearance of the image from the
screen. The long band, upon which the
images are produced in colors by Il spc
cial process may be moved in either di-
rection before the lantern, when the inn
ages are projected through lens upon
an inclined mirror, which projects them
upon transparent screen. Another pro
lecting lantern causes the appearance on
the stage of the scenery amid which the
characters move.
FACTS ABOUT LGGHT AND SoUyD.-
Light falling on any ordinary substance
produces sound Throw a beam of it on
a glass vessel full of lampback and
sound may be detected. Or. pass the
light through a prism and form rain
bow; as the rainbow falls on the glass
vessel distinct sound will be caused.
Red and blue light makes a louder sound
than green. Fill the glass vessel with
red worsted aud throw the green light
from prism on it and the noise is very
loud. And so, one by one. we penetrate
the mysteries of nature. Stand mt one
end of a stone or brick wall, and have
some one strike the other end with
hammer You will detect two distinct
sounds from each blow Of the hammer.
One comes to your ear through the
medium Of the air; the otherthrough the
wall itself From particle to particle,
whether of air, stone Or any other sub
stance, the impulse Of sound travels. and
so it's that you hear two strokes instead
of one The discovery of the fact that
the fall of light creates sound is new
the double sounds from brick or stone
is old, and any one can test il
for himself. Explode frc-cracker
in an empty barrel. and it
sounds about as loud as gun; fire a gun
off on the top of a mountain. where the
air is very thin, and it will sound about
as loud as a firc-cracker. Sound travels
at the rate Of about T., 100 feet every sec
ond. Fire Il gun and any one at dis
lance will see the fash before he hears
the sound; light goes faster than sound, !
you see. | stood, the other day. on the |
platform Of IA railroad station in the |
country. As the cars got near they |
whistled, also while going by, and again
while going on past Us. | noticed a |
singular thing. and that was that four
hundred yards of the whistle sounded |
one note higher each way That is, at |
the station it was "B. four hundred |
yards before it got there the same whistle |
had been &C. aud after falling. directly |
opposite the station, to "3. 'whent train |
got four or five hundred ward. away again |
the sound went up 10 C again II was
owing 70 the puisatons az sound being |
4 VI IL