Sacramento daily record-union. [volume] (Sacramento [Calif.]) 1875-1891, 1880-04-17
SCIENCE FARMLAND.
HOME EXPERIMENTS FOR OUR YOUNGER
READERS.
NUMBER FoUR.l

NUMBER FoUR.l
TWENTY EIGHTH EXPERIMENT. The ad-
hesion between air and water is great and
may be illustrated by pouring water down
long tube which rests upon block of
wood. Allow the water to flow down the
tube and escape SO as to leave a space
above the water, and just as that space be-
gins to be created make a smoke at the
top of the tube, and as the water
declines, and as smoke is heavy and tends
TO sink, it will be seen to follow the air
down the tube, showing that the air is fol
lowing the water also.
TWENTY. NINTH EXPERIMENT The crys-
Utilization of salts form the basis Of many
an interesting experiment. There are
four great orders of salts, the oxy-salts,
the hydro-salts, the sulphur salts, and the
haloid salts To cause substance to crys-
tallize its particles must be first set free.
Dissolve powdered alum in water-its par
ticles are set free thereby and the solvent
power of the water opposes gravitation and
every part of the solution is equally I'M
pregnated with the alum. How shall you
proceed to bring the alum to % solid state
again? BY evaporating the excess of water
by heat or long atmospheric exposure III a
shallow vessel. A thin film first forms and
this is made up of crystals. Take drop of
the solution and put it on a bit of glass
and it viii rapidly fill with minute
crystals, If the evaporation has been car
ried sufficiently far Place the solution in
shallow dish after being well evaporated
by heat, and as it cools the crystals of
alum will form and take on beautiful
shapes of the utmost regularity, denoted
by geometrical term called octohedral,
or eght-sided crystals. If bismuth is
melted in crucible, and when cooling
and Just as the skin or crust is forming, if
two small holes are instantly made by
rod of iron, and the liquid metal poured
out from the inside 1.-THE one hole for the
metal, the other for the ingress of airy, on
breaking the crucible the bismuth is found
to be crystallized in the most lovely
cubes. Sulphur by similar plan may
be crystallized in prismatic crystals.
Saturate boiling water with Glauber's salt,
of which one ounce. and half of water
will usually dissolve about two ounces.
Pour while boiling hot into clean oil-fasks,
or walls of any kind, previously heated in
the oven, and Immediately cork them or
tie strips of wetted bladder. No crystal
lization will take place when cold until
atmospheric air is admitted, which, being
let in by hole in the cover. the crystals.
almost instantly form. Ii qualification
does not take place rapidly, drop in a
minute crystal of Glauber's salt, and the
whole mass will crystalline.
THIRTIETH EXPERIMENT. con-
sists of three parts-the outer film, which
has little or no luminosity, a second film
where carbon is deposited and produces
light, and an interior space containing I'M
burnt gas. This can be seen by close ex-
animation of the flame of a candle, and
the hollow space can be shown by pressing
piece of smooth-sized paper down upon
candle flame for moment when it will be
found that the paper will be blackened ex-
cept in the center.
THIRTY FIRST EXPERIMENT. set in
motion produces waves of sound. The
theoretical ether pervading all matter like
wise set in motion produces light. You
may illustrate vibration by using finger
glass. Hang a small ebony ball by silk
thread to bent brass wire directly over it,
so that the ball may touch either the out
side or inside of the glass. Attention must
be given to the quiescence of the ball when
violin bow is lightly moved over
the edge of the glass without pro-
ducing sound, and to the contrary
effect obtained by so moving and
pressing the bow that sharp
sound is emitted, when Immediately
the little ball is thrown off from the edge,
the repulsive action being continued as
long as the sound is produced by the vi
bration of the glass. The vibrations being
first set up in the glass and communicated
TO the surrounding air, sound is pro-
duced. If the glass be vibrated or bell
rung in a vacuum no sound will be pro-
duced, because the glass will not
be surrounded with air Compare the sun
to the 6nger-glass, suppose it to be en-
dowed with a vibratory motion, and that
it sets the ether in motion in place of the
air, throwing it into waves which travel
through space, and you will see how the
impressions of light may be conveyed from
a luminous object Throw a stone into
pool of water and note the rings of waves
produced as the surrounding molecules of
water are helped up above their level,
descending again by the force OF gravita- !
ton, and again throwing up other waves,
each subsiding one raising another until
the force of the original wave dies, or is
lost upon the edge OF the pool in faint |
ripples. But remember the water does not |
really travel at all, but that the force is
propagated by the rising and falling of |
each separate particle of water as it is dis |
turbed by the momentum of the descend |
ing wave before it. These experiments |
will serve to illustrate the theory of vi |
bratory mediums and progressive action,
and the undulatory theory with regard to |
light, and its propagation through space,
by which it is assumed that the |
whole universe is filled with high |
" elastic race medium of most atten-
uated nature called ether, possessing the |
property of inertia, but not of gravitation.
Light is thrown out on all sides from |
luminous body, like the spokes OF wheel,
and in the absence of airy obstruction, the /
rays are distributed equally on all sides. |
As natural consequence arising from the |
divergence of each ray from the other, the
intensity of light decreases as the distance
from the luminous source increases, and vice |
versa. To illustrate, take folding fan
and open it, and let the rods or Stats repre-
sent the diverging rays. At the pivot they
are all united and are thickly placed, but
toward the outer edge of the fan they are
wide apart. Place the finger at the outer
edge; it viii touch but one rod or slat
lone ray of lightL, but place it near the
pivot and it will intercept many rods Tor
rays) This will give you some idea of
how the intensity of light is measured by
the photOmeter, which We shall explain in
the next experiment.