in the Office of the Librarian of Congress at
Washington, D. C.
How to Become a Scientist.
Chemistry, optics, pneumatics, mechanics, and mathematics, all
contribute their share towards furnishing recreation and sport for the
social gathering, or the family fireside. The magical combinations
and effects of chemistry have furnished an almost infinite variety of
pleasant experiments, which may be performed by our youthful friends
with great success if a little care be taken; and the other branches of
natural science are nearly as replete with interest.
The following _repertoire_ of such tricks and illusions will be found
exceedingly complete, although pains have been taken to select only
the best and most startling of them. A large number are entirely new,
but are described with sufficient clearness to enable any person of
ordinary intelligence to become expert in them, with a little practice.
Chemical Amusements.
Chemistry is one of the most attractive sciences. From the beginning to
the end the student is surprised and delighted with the developments of
the exact discrimination, as well as the power and capacity, which are
displayed in various forms of chemical action. Dissolve two substances
in the same fluid, and then, by evaporation or otherwise, cause them to
reassume a solid form, and each particle will unite with its own kind,
to the entire exclusion of all others. Thus, if sulphate of copper and
carbonate of soda are dissolved in boiling water, and then the water
is evaporated, each salt will be reformed as before. This phenomenon
is the result of one of the first principles of the science, and as
such is passed over without thought; but it is a wonderful phenomenon,
and made of no account, only by the fact that it is so common and so
familiar.
It is by the action of this same principle, “chemical affinity,” that
we produce the curious experiments with
Sympathetic Inks.
By means of these, we may carry on a correspondence which is beyond the
discovery of all not in the secret. With one class of these inks, the
writing becomes visible only when moistened with a particular solution.
Thus, if we write to you with a solution of the sulphate of iron, the
letters are invisible. On the receipt of our letter, you rub over the
sheet a feather or sponge, wet with a solution of nut-galls, and the
letters burst forth into sensible being at once, and are permanent.
2. If we write with a solution of sugar of lead, and you moisten with
a sponge or pencil, dipped in water impregnated with sulphureted
hydrogen, the letters will appear with metallic brilliancy.
3. If we write with a weak solution of sulphate of copper, and you
apply ammonia, the letters assume a beautiful blue. When the ammonia
evaporates, as it does on exposure to the sun, the writing disappears,
but may be revived again as before.
4. If you write with the oil of vitriol very much diluted, so as to
prevent its destroying the paper, the manuscript will be invisible
except when held to the fire, when the letters will appear black.
5. Write with cobalt dissolved in diluted muriatic acid; the letters
will be invisible when cold, but when warmed they will appear a bluish
green.
We are almost sure that our secrets thus written will not be brought
to the knowledge of a stranger, because he does not know the solution
which was used in writing, and, therefore, does not know what to apply
to bring out the letters.
To Light a Candle Without Touching the Wick.
Let the candle burn until it has a good long snuff; then blow it out
with a sudden puff, a bright wreath of white smoke will curl up from
the hot wick. Now, if a flame be applied to this smoke, even at a
distance of two or three inches from the candle, the flame will run
down the smoke and rekindle the wick in a very fantastic manner. To
perform this experiment nicely, there must be no draught or “banging”
doors while the mystic spell is rising.
Magic Milk.
Lime-water is quite transparent, and clear as common spring water; but
if we breathe or blow into it, the bright liquid becomes opalescent and
as white as milk.
The best way to try this simple experiment is to put some powdered
quicklime into a wine bottle full of cold water; shake them well
together, now and then, for a day; then allow the bottle to remain
quiet till the next day, when the clear lime-water may be poured off
from the sediment. Now fill a wine-glass or tumbler with the lime-water
thus made, and blow through the liquid with a glass tube, a piece of
new tobacco-pipe, or a clean straw, and in the course of a minute or
so--as the magicians say--“the water will be turned into milk.” By
means of this pastime “Wise Men” can ascertain which young ladies are
in love and which young gentlemen are not. With a shrewd guess they
present, as a test, a glass of lime-water to the one and of pure water
to the other, with unerring effect.
The Mimic Vesuvius.
This experiment is a demonstration of the heat and light which are
evolved during chemical combination. The substance phosphorus has a
great affinity for oxygen gas, and wherever it can get it from it
will, especially when aided by the application of heat. To perform
this experiment, put half a drachm of solid phosphorus into a Florence
oil-flask, holding the glass slantingly, that the phosphorus may not
take fire and break the glass; pour upon it a gill and a half of
water, and place the whole over a tea-kettle lamp, or any common lamp
filled with spirits of wine; light the wick, which should be about
half an inch from the flask; and as soon as the water is boiling hot,
streams of fire, resembling sky-rockets, will burst at intervals
from the water; some particles will also adhere to the sides of the
glass, immediately displaying brilliant rays, and thus continue until
the water begins to simmer, when a beautiful imitation of the aurora
borealis will commence and gradually ascend until it collects into a
pointed cone at the mouth of the flask; after a half a minute, blow
out the flame of the lamp, and the apex of fire that was formed at
the mouth of the flask will rush down, forming beautiful illumined
clouds of fire, rolling over each other for some time; and when these
disappear, a splendid hemisphere of stars will present itself. After
waiting a minute or two, light the lamp again, and nearly the same
phenomena will be displayed as at the beginning. Let a repetition of
lighting and blowing out the lamp be made for three or four times,
so that the number of stars may be increased; and after the third or
fourth act of blowing out the lamp, the internal surface of the flask
will be dry. Many of the stars will shoot with great splendor from side
to side, while others will appear and burst at the mouth of the flask.
What liquid remains in the flask will serve for the same experiment
three or four times, without adding any water. Care should be taken,
after the operation is over, to put the flask in a cool and secure
place.
The Real Will-o’-the-Wisp.
Into a small retort place about an ounce of strong liquor of potash;
that is, pure potash dissolved in water, together with about a drachm
of phosphorus. Let the neck or beak of the retort dip into a saucer of
water, say half an inch deep; now very gently heat the liquid in the
retort with a spirit-lamp until it boils. In a few minutes the retort
will be filled with a white cloud; then the gas generated will begin
to bubble at the end of the saucer; a minute more, each bubble, as it
issues from the boiling fluid, will _spontaneously take fire_ as it
comes into the air, forming at the same time the philosopher’s ring of
phosphoric acid. Care is required in handling phosphorus; but our young
chemical readers will, we think, not forego this wonderful experiment
for the want of due attention; for, without proper care on their part,
we must give up showing them wonders even greater than these.
The Paper Oracle.
Some amusement may be obtained among young people by writing, with
common ink, a variety of questions, on different bits of paper, and
adding a pertinent reply to each, written with nitro-muriate of gold.
The collection should be suffered to dry, and put aside, until an
opportunity offers for using them. When produced, the answers will be
invisible; desire different persons to select such questions as they
may fancy, and take them home with them; then promise, if they are
placed near the fire during the night, answers will appear written
beneath the questions in the morning; and such will be the fact, if the
paper be put in any dry, warm situation.
The Mimic Gas-House.
This shows a simple way of making illuminating gas, by means of a
tobacco-pipe. Bituminous coal contains a number of chemical compounds,
nearly all of which can, by distillation, be converted into an
illuminating gas; as with this gas nearly all our cities are now
lighted in the dark hours of night. To make it, obtain some coal-dust
(or walnut or butternut meats will answer), and fill the bowl of a pipe
with it; then cement the top over with some clay; place the bowl in the
fire, and soon smoke will be seen issuing from the end of the stem;
when that has ceased coming apply a light and it will burn brilliantly
for several minutes; after it has ceased, take the pipe from the fire
and let it cool, then remove the clay, and a piece of coke will be
found inside: this is the excess of carbon over the hydrogen contained
in the coal, for all the hydrogen will combine with carbon at a high
temperature, and make what are called hydrocarbons--a series of
substances containing both these elemental forms of matter.
Alum Basket.
Make a small basket, about the size of the hand, of iron wire or split
willow; then take some lamp-cotton, untwist it, and wind it around
every portion of the basket. Then mix alum, in the proportion of one
pound with a quart of water, and boil it until the alum is dissolved.
Pour the solution into a deep pan, and in the liquor suspend the
basket, so that no part of it touch the vessel or be exposed to the
air. Let the whole remain perfectly at rest for twenty-four hours;
when, if you take out the basket, the alum will be found prettily
crystallized over all the limbs of the cottoned frame.
In like manner, a cinder, a piece of coke, the sprig of a plant, or
any other object, suspended in the solution by a thread, will become
covered with beautiful crystals.
If powdered tumeric be added to the hot solution, the crystals will be
of a bright yellow; if litmus be used instead, they will be of a bright
red; logwood will yield them of a purple, and common writing-ink, of
a black tint; or, if sulphate of copper be used instead of alum, the
crystals will be of fine blue.
But the colored alum crystals are much more brittle than those of pure
alum, and the colors fly; the best way of preserving them is to place
them under a glass shade, with a saucer containing water. This keeps
the atmosphere constantly saturated with moisture, the crystals never
become too dry, and their texture and color undergo but little change.
The Magic Bottle.
This trick, if well managed, is one of the most wonderful that can
be performed in a drawing-room without apparatus; but it requires
dexterity at the conclusion.
The person performing the trick offers to pour from a common
wine-bottle, port-wine, sherry, milk, and champagne, in succession, and
in any order.
To accomplish the trick, you must make solutions of the following
chemicals, and label the bottles with numbers, thus:
No. 1. A mixture of two parts perchloride of iron, and one part
sulphuric acid (vitriol).
No. 2. A strong solution of the sulphocyanate of potash.
No. 3. A strong solution of acetate of lead.
No. 4. A solution of bicarbonate of soda, or potash.
No. 5. A clear solution of gum arabic.
Procure a champagne-bottle, and wash it out well; then pour three
teaspoonfuls of No. 1 into it. As the quantity is very small, it will
not be observed, especially if you are quick in your movements. Pour
some distilled or rain water into a common water-bottle, or jug, and
add a tablespoonful of No. 5 to it; then set it aside, ready for use.
Provide some wine-glasses, of four different patterns, and into one
pattern put one drop of solution No. 2; into another, three drops of
solution No. 2; rinse the third with solution No. 3, and the fourth
with solution No. 4.
Arrange the glasses on a small tray, remembering the solutions that
were poured into each pattern.
Everything being ready, take the champagne bottle that you have
prepared, from two or three others, and holding it up, to show the
company that it is clear and empty; you must desire some person to hand
you the water-bottle or jug, and then fill up the bottle with the water.
Pour some of the contents of the bottle into an unprepared glass, in
order to show that it is water; then say: “Change to champagne,” and
pour the liquid from the bottle into one of the glasses rinsed with No.
4; then pour into the glass containing _three drops_ of No. 2, and it
will change to port wine; but if poured into the glass rinsed with No.
3, it will change to milk; and if into the glass with one drop of No.
2, it will produce sherry.
Be careful in pouring the fluid from the bottle, not to hold it high
above the glasses, but to keep the mouth of it close to the edges,
otherwise persons will observe that it undergoes change of color after
it is poured into them; and, on this account, the glasses should be
held rather high.
As all the solutions used in the above trick are deleterious, they
should not be left about in the way of children, and, of course, the
fluid in the wine-glasses must not even be tasted; but if any of the
company wish to drink the wines you have made, then the tray must be
adroitly exchanged for another with the proper wines placed on it.
The Faded Rose Restored.
Take a rose that is quite faded, and throw some sulphur on a
chafing-dish of hot coals; then hold the rose over the fumes of the
sulphur, and it will become quite white; in this state dip it into
water, put it into a box, or drawer, for three or four hours, and when
taken out it will be quite red again.
The Protean Liquid.
A red liquor, which, when poured into different glasses, will become
yellow, blue, black, and violet, may be thus made: Infuse a few
shavings of logwood in common water, and when the liquor is red, pour
it into a bottle; then take three drinking-glasses, rinse one of them
with strong vinegar, throw into the second a small quantity of pounded
alum, which will not be observed if the glass has been newly washed,
and leave the third without any preparation. If the red liquor in the
bottle be poured into the first glass it will assume a straw color;
if into the second, it will pass gradually from bluish-gray to black,
provided it be stirred with a bit of iron, which has been privately
immersed in good vinegar; in the third glass the red liquor will assume
a violet tint.
The Changeable Ribbon.
Dip a rose-colored ribbon into nitric acid, diluted with eight or ten
parts of water, and as soon as the color disappears, which it will
do in a short time, take out the ribbon and put it into a very weak
alkaline solution, when the alkali will quickly neutralize the acid,
and the color will reappear.
The Chemical Chameleon.
Put a drachm of powdered nitrate of cobalt into a vial, containing an
ounce of the solution of caustic potash, when the decomposition of the
salt, and precipitation of a blue oxide of cobalt will take place. Cork
the vial, and the liquid will assume a blue color, from which it will
pass to a lilac, afterward to a peach tint, and finally to a light red.
Musical Flame.
Fit a good cork into a wine-bottle; burn a hole through the cork with a
round iron skewer, and into it fix a piece of tobacco pipe about eight
inches long. Put into the bottle about two or three ounces of zinc, in
slips, such as the waste cuttings from a zinc-worker; now pour water
on to the zinc until the bottle is more than half full; then add about
three parts of a wine-glassful of sulphuric acid (oil of vitriol);
this causes a rapid effervescence at first, but which subsides to a
moderate and continuous boiling for a lengthened period; as soon as the
boiling is regular, the cork with the pipe through it may be inserted
into the bottle. If a light be placed to the end of the pipe, a flame
will be produced, which will continue to burn so long as there is any
visible action in the bottle. This flame is the ignited hydrogen gas
(water gas), resulting from the decomposition of water by the acid and
zinc, and as such is an exceedingly interesting experiment. Now, to
be musical, procure a glass or metal pipe, about sixteen or eighteen
inches long, and from half to three-quarters of an inch in diameter;
place the tube over the flame, and allow the pipe to be about three to
five inches up the tube, which will act as a kind of high chimney; it
must be held perfectly steady and upright, at a particular distance up
the tube, which varies according to the size of the flame. A beautiful
sound is thus produced, similar to an organ-pipe. This sound, or
“musical flame,” varies in note according to the diameter of the tube,
being deeper or more bass as the tube is increased in size. By using
various-sized tubes, different sounds are thus readily produced. The
true explanation of this singular experiment remains yet to be solved.
Optical Amusements.
The science of optics affords an infinite variety of amusements, which
cannot fail to instruct the mind, as well as delight the eye. By the
aid of optical instruments we are enabled to lessen the distance to
our visual organs between the globe we inhabit and “the wonders of the
heavens above us;” to watch “the stars in their courses,” and survey
at leisure the magnificence of “comets importing change of times and
states;” to observe the exquisite finish and propriety of construction
which are to be found in the most minute productions of the earth;--to
trace the path of the planet, in its course around the magnificent orb
of day, and to detect the pulsation of the blood, as it flows through
the veins of an insect. These are but a few of the powers which this
science offers to man; to enumerate them all would require a space
equal to the body of our work; neither do we propose to notice the
various instruments and experiments which are devoted to purposes
merely scientific; it being our desire only to call the attention of
our juvenile readers to such things as combine a vast deal of amusement
with much instruction, to inform them as to the construction of the
various popular instruments; to show the manner of using them, and
to explain some of the most attractive experiments which the science
affords. By doing thus much, we hope to offer a sufficient inducement
to extend inquiry much further than the information which a work of
this nature will enable us to afford.
The Camera Obscura.
This is a very pleasing and instructive optical apparatus, and may
be purchased for a small sum. But it may be easily made by the young
optician. Procure an oblong box, about two feet long, twelve inches
wide, and eight high. In one end of this a tube must be fitted
containing a lens, and be made to slide backward and forward, so as to
suit the focus. Within the box should be a plain mirror, reclining
backward from the tube at an angle of forty-five degrees. At the top
of the box is a square of unpolished glass, upon which, from beneath,
the picture will be thrown, and may be seen by raising the lid. To use
the camera, place the tube with the lens on it opposite to the object,
and having adjusted the focus, the image will be thrown upon the ground
glass, as above stated, where it may be easily copied by a pencil or in
colors.
The Magic Lantern.
The object of this ingenious instrument is to represent, in a dark
room, on a white wall or cloth, a succession of enlarged figures of
remarkable, natural, or grotesque objects. It consists of a tin box,
with a funnel on the top, and a door on one side of it. This funnel,
by being bent, serves the double purpose of letting out the smoke and
keeping in the light. In the middle of the bottom of the box is placed
a movable lamp, which must have two or three good lights, at the height
of the center of the polished tin reflector. In the front of the box,
opposite the reflector, is fixed a tin tube, in which there slides
another tube. The sliding tube has, at its outer extremity, a convex
lens fixed in it, of three inches in diameter. The focus of the smaller
of these lenses may be about five inches. Between the stationary tube
and the lamp, there must be a split or opening to admit of the passage
of glass sliders, mounted in paper or wooden frames, upon which sliders
it is that the miniature figures are painted, which are intended to be
shown upon the wall. The distinctness of the enlarged figures depends
not only upon the goodness of the magnifying glass, but upon the
clearness of the light yielded by the lamp. It may be purchased ready
made of any optician.
_To Paint the Glasses._--The slides containing the objects usually
shown in a magic lantern are to be bought of opticians with the
lantern, and can be procured cheaper and better in this way than by any
attempt at manufacturing them. Should, however, the young optician wish
to make a few slides, of objects of particular interest to himself,
he may proceed as follows: Draw on a paper the subject you desire to
paint. Lay it on a table or any flat surface, and place the glass over
it; then draw the outlines with a very fine pencil, in varnish mixed
with black paint, and, when dry, fill up the other parts in their
proper colors. Transparent colors must be used for this purpose, such
as carmine, lake, Prussian blue, verdigris, sulphate of iron, tincture
of Brazil wood, gamboge, etc.; and these must be tempered with a strong
white varnish, to prevent their peeling off. Then shade them with
black, or with bistre, mixed with the same varnish.
_To Exhibit the Magic Lantern._--The room for the exhibition ought to
be large, and of an oblong shape. At one end of it suspend a large
sheet, so as to cover the whole of the wall. The company being all
seated, darken the room, and placing the lantern with its tube in
the direction of the sheet, introduce one of the slides into the
slit, taking care to invert the figures; then adjust the focus of
the glasses in the tube, by drawing it in or out, as required, and a
perfect representation of the object will appear.
_Effects of the Magic Lantern._--Most extraordinary effects may be
produced by means of the magic lantern; one of the most effective of
which is a tempest at sea.
This is effected by having two slides painted, one with the tempest as
approaching on one side, and continuing in intensity till it reaches
the other. Another slide has ships painted on it, and while the lantern
is in use, that containing the ships is dexterously drawn before the
other, and represents ships in the storm.
The effects of sunrise, moonlight, starlight, etc., may be imitated
also, by means of double sliders; and figures may be introduced
sometimes of fearful proportions.
Heads may be made to nod, faces to laugh; eyes may be made to roll,
teeth to gnash; crocodiles may be made to swallow tigers; combats may
be represented; but one of the most instructive uses of the slides is
to make them illustrative of astronomy, and to show the ratio of the
seasons, the cause of the eclipses, the mountains in the moon, spots
on the sun, and the various motions of the planetary bodies and their
satellites.
The Phantasmagoria.
Between the phantasmagoria and the magic lantern there is this
difference: in common magic lanterns the figures are painted on
transparent glass; consequently the image on the screen is a circle of
light, having figures upon it; but in the phantasmagoria all the glass
is opaque, except the figures, which, being painted in transparent
colors, the light shines through them, and no light can come upon the
screen except that which passes through the figure.
There is no sheet to receive the picture, but the representation
is thrown on a thin screen of silk or muslin, placed between _the
spectators and the lantern_. The images are made to appear approaching
and receding, by removing the lantern further from the screen,
or bringing it nearer to it. This is a great advantage over the
arrangements of the magic lantern, and by it the most astonishing
effects are often produced.
Dissolving Views.
The dissolving views, by which one landscape or scene appears to pass
into the other while the scene is changing, are produced by using two
magic lanterns, placed side by side, and that can be inclined towards
each other when necessary, so as to mix the rays of light, proceeding
from the lenses of each, together, which produces that confusion of
images, in which one view melts, as it were, into the other, which
gradually becomes clear and distinct.
How to Raise a Ghost.
The magic lantern or phantasmagoria may be used in a number of
marvelous ways, but in none more striking than in raising an apparent
specter. Let an open box, about three feet long, a foot and a half
broad, and two feet high, be prepared. At one end of this place a small
swing dressing-glass, and at the other let a magic lantern be fixed,
with the lenses in a direction towards the glass. A glass should now
be made to slide up and down in the groove to which a cord and pulley
should be attached, the end of the cord coming to the lower part of
the left hand side. On this glass the most hideous specter that can
be imagined may be painted, but in a squat or contracted position,
and when all is done, the lid of the box must be prepared by raising
a kind of gable at the end of the box, and in its lower part an oval
hole should be cut sufficiently large to suffer the rays reflected
from the glass to pass through them. On the top or the box place a
chafing-dish, upon which put some burning charcoal. Now light the lamp
in the lantern, sprinkle some powdered camphor or white incense on the
charcoal, adjust the slide on which the specter is painted, and the
image will be thrown upon the smoke. In performing the feat the room
must be darkened, and the box should be placed on a high table, that
the hole through which the light comes may not be noticed.
To Imitate a Mirage.
Provide a glass tumbler two-thirds full of water, and pour spirits of
wine upon it; or pour into a tumbler some syrup, and fill it up with
water; when mixed, the object seen through it will be inverted.
Two-fold Reflections.
Provide a circular piece of glass, and with a common awl, moistened
with spirits of turpentine, pierce the center of the glass; hold it
encircled with the fingers and thumb in the sunshine, or the strong
light of a lamp, when these striking effects will be produced: If
the glass be _red_, the hole pierced in the middle will be reflected
_green_; if the glass be _green_, the spot will be _red_; if _blue_,
_orange_; and if _yellow_, _indigo_.
The Thaumatrope.
Cut out a piece of card-board of circular form, and affix to it six
pieces of string, three on each side. Paint on one side of the card a
bird, and on the other a cage, taking care to paint the bird upside
down, or the desired effect will not be produced. When showing the toy,
take hold of the center strings, between the forefinger and thumb,
and twirl the card rapidly around, and the bird will appear snugly
ensconced in its cage. The principle on which this effect is produced
is, that the image of any object received on the retina or optic
nerve is retained on the mind about eight seconds after the object
causing the impression is withdrawn, being the memory of the object;
consequently, the impression of the painting on one side of the card is
not obliterated ere the painting on the other side is brought before
the eye. It is easy to understand from this fact how both are seen
at once. Many objects will suit the thaumatrope, such as a juggler
throwing up two balls on one side, and two balls on the other; and
according to the pairs of strings employed, he will appear to throw
up two, three, or four balls; the body and legs of a man on one side,
and the arms and head on another; a horse and his rider; a mouse and
trap. But we leave it to the ingenuity of our readers to devise for
themselves.