Chapter I: Part 1

_To the_
LOVERS OF HOME
_THIS_
Little Manual
OF
AMUSING PHENOMENA
FOR
Family Recreation
IS
RESPECTFULLY
_Dedicated_]

REVISED AND IMPROVED.

PHILADELPHIA: H. PERKINS, 134 CHESTNUT STREET.
MDCCCXXXVIII.

ENTERED, according to Act of Congress, in the year 1838, by HENRY PERKINS, in the Clerk’s office of the District Court for the Eastern District of Pennsylvania.

Printed by Haswell, Barrington, and Haswell.

To furnish the ingenious youth with the means of relieving the tediousness of a long winter’s or a wet summer’s evening,—to enable him to provide for a party of juvenile friends, instructive as well as recreative entertainment, without having recourse to any of the vulgar modes of killing time,—to qualify the hero of his little circle to divert and astonish his friends, and, at the same time, to improve himself, are the principal objects of the following little Work.

The boy whose wonder and curiosity have been excited by the experiments of the scientific lecturer, or the illusions of the ventriloquist, will here find many of these mysteries unveiled, and plain directions for performing them, divested, as far as possible, of scientific or technical language. Many of the descriptions are strictly original, and now, for the first time, appear in print; and especial care has been taken to introduce only such Experiments as are adapted for performance at the parlour or drawing-room table, or fire-side, and such as are practicable without expensive chemical or mechanical apparatus, and require no implements beyond those which any ingenious youth may readily furnish from his own resources, or at a trifling expense.

Another object of these pages is to inform, without being dryly scientific,—by imparting interesting facts, to stimulate the young experimentalist to inquire into the laws that regulate them,—by aiding him to acquire dexterity of practice, to smooth the road to the development of principles,—and, above all, to enable him to escape an imputation which every boy of spirit would consider the depth of disgrace,—that of being “No Conjuror!”

Transmutations.
_Page_
The Spectral Lamp 1
Curious Change of Colours 2
The Protean Light 2
The Chameleon Flowers 3
To change the Colours of Flowers 3
Changes of the Poppy 3
To change the Colour of a Rose 4
Light changing White into Black 4
The Visibly growing Acorn 4
Changes in Sap-Green 5
To revive apparently dead Plants 5
Singular effect of Tears 5
Beauties of Crystallization 5
To crystallize Camphor 7
Crystallized Tin 7
Crystals in hard Water 7
Varieties of Crystals 7
Heat from Crystallization 8
Splendid Sublimation 8
Artificial Ice 8
Magic Inks 8
Chameleon Liquids 9
The Magic Dyes 9
Wine changed into Water 10
Two colourless transparent Liquids become black and opaque 10
Two colourless Fluids make a coloured one 10
Change of colour by colourless Fluids 10
To change a Blue Liquid to White 11
Veritable “Black” Tea 11
Restoration of Colour by Water 11
The Magic Writing 12
Two Liquids make a Solid 12
Two Solids make a Liquid 12
A solid opaque mass made a transparent Liquid 12
Two cold Liquids make a hot one 12
Quadruple Transmutation 13
Quintuple Transmutation 13
Combination of Colours 13
Union of two Metals without Heat 13
Magic Breath 13
Two Bitters make a Sweet 14
Visible and Invisible 14

Sight and Sound.
Artificial Mirage 17
Motion of the Eye 18
Single Vision with two Eyes 19
Two objects seen as one 19
Only one object can be seen at a time 20
Straight objects seen crooked 20
Optical Illusion 21
Pin-hole Focus 21
Optical Deceptions 22
Accuracy of Sight 22
Visual Deception 23
Handwriting upon the Wall 23
Imitative Haloes 23
To read a Coin in the dark 24
To make a Prism 24
Optical Augmentation 25
Gold Fish in a glass Globe 26
Colours produced by the unequal action of Light upon the Eyes 26
Optical Deception 27
Coloured Shadows 27
Colours of Scratches 27
Ocular Spectra 28
Beautiful Colours of Mother of Pearl 28
White Letters seen further than Black 29
Artificial Rainbow 29
Fringe about a Candle 29
The Double Coloured Reflection 30
Luminous Cross 30
Ring of Colours round a Candle 30
Simple and Cheap Opera-glass 31
Multiplying Theatres 31
Apparatus for Writing in the Dark 32
Portable Microscope 33
The Phenakistiscope or Stroboscope 34
To look at the Sun without injury 35
Brilliant Water Mirror 35
Optical Illusion under Water 35
The Magic Wheels 36
Acoustic Rainbow 37
Transmission of Sound 37
Progress of Sound 39
Sound turning Corners 39
To tell the distance of Thunder 40
Hearing by the Touch 40
Conversation for the Deaf 40
Glass broken by the Voice 41
Figures produced by Sound 41
Transmitted Vibration 42
Double Vibration 42
Champagne and Sound 42
Music from Palisades 43
Theory of the Jew’s Harp 43
Music of the Snail 44
To tune a Guitar without the assistance of the Ear 44
Music from Glass or Metal Rods 44
The Tuning-fork a Flute-player 45
Musical Bottles 46
Theory of Whispering 46
Theory of the Voice 46
Sound along a Wall 47
Sounds more audible by Night than by Day 47
Musical Echo 47
Ventriloquism 48

Light and Heat.
Flashes of Light upon revolving Wheels 53
Decomposition of Light 54
Solar Refraction 54
Incantations 55
To imitate the Light of the Sea 55
Instantaneous Lights 56
To colour the Flame of a Candle 57
To divide the Flame of a Candle 57
Cane Wick Lamp 58
Camphor and Platinum Lamp 58
Platinum and Ether Lamp 58
Floating Light 59
Substitute for a Wax Taper 59
Phosphorescent Fish 59
The Luminous Spectre 59
Light, a Painter 60
Effect of Light upon Crystallization 60
Effect of Light on Plants 60
Instantaneous Light upon Ice 61
White Light from Zinc 61
Brilliant Light from two Metals 61
Brilliant Light from Steel 61
Lighted Tin 62
Light from Gilt Buttons 62
Light from a Flower 62
Light from Sugar 62
Light from the Potato 63
Light from the Oyster 63
Light from Derbyshire Spar 63
Light from Oyster-shells 64
Rings of Light in Crystal 64
To strike Light with Cane 64
Cause of Transparency 64
Transparency of Gold 65
Tint changed by Thickness 65
Shadows made darker by increased Light 65
Miniature Thunder and Lightning 66
The Burning Glass 66
Magic of Heat 66
Repulsion by Heat 67
Heat passing through Glass 68
Metals unequally influenced by Heat 68
Spontaneous Combustion 69
Inequality of Heat in Fire irons 69
Expansion of Metal by Heat 69
Evaporation of a Metal 69
A Floating Metal on Fire 70
Heat and Cold from Flannel 70
Ice melted by Air 70
To hold a hot Tea-kettle on the Hand 70
Incombustible Linen 71
The Burning Circle 71
Water of different Temperatures in the same Vessel 71
Warmth of different Colours 71
Substitute for Fire 72

Gas and Steam.
Laughing Gas 75
The Luminous Wand 76
To make Carbonic Acid Gas 76
Carbonic Acid Gas in Wine or Beer Vessels 76
To extinguish Flame with Gas 77
Effect of Hydrogen on the Voice 77
Magic Taper 78
The Gas Candle 78
Gas Bubbles 78
Gas-light in the day-time 79
Miniature Balloons 79
Miniature Gas-lighting 79
Musical Gas 80
Miniature Will o’-the-wisp 81
Phosphoric Illumination 81
Combustion of Iron in Oxygen Gas 81
Glow-worm in Oxygen Gas 82
Luminous Charcoal 82
Brilliant Combustion in Oxygen 82
Flame from Cold Metals 83
Phosphorus in Chlorine 83
Caoutchouc Balloons 84
To increase the Light of Coal Gas 84
Gas from Indian Rubber 84
Ether Gas 85
Magic Vapour 85
Gas from the union of Metals 85
Invisible Gases made Visible 86
Light under Water 86
Gaseous Evanescence 86
Violet-coloured Gas 86
To collect Gases 87
The Deflagrating Spoon 87
What is Steam? 87
The Steam Engine simplified 88
To boil Water by Steam 88
Distillation in Miniature 89
Candle or Fire Crackers 89
Steam from the Kettle 89

Fire, Water, and Air.
Coloured Flames 93
Yellow Flame 94
Orange-coloured Flame 94
Emerald Green Flame 94
Instantaneous Flame 94
The Cup of Flame 95
To cool Flame by Metal 95
Proof that Flame is Hollow 95
Camphor sublimed by Flame 95
Green Fire 96
Brilliant Red Fire 96
Purple Fire 96
Silver Fire 97
The Fiery Fountain 97
The Artificial Conflagration 97
Inflammable Powder 97
Combustion without Flame 98
Combustion of Three Metals 98
To make Paper Incombustible 98
Singular Experiments with Glass Tubes 98
Aquatic Bomb 99
Heat not to be estimated by Touch 99
Flame upon Water 100
Rose-coloured Flame on Water 100
To set a Mixture on Fire with Water 100
Waves of Fire on Water 100
Explosion in Water 101
Water from the Flame of a Candle 101
Formation of Water by Fire 101
Boiling upon Cold Water 101
Currents in Boiling Water 102
Hot Water lighter than Cold 102
Expansion of Water by Cold 102
The Cup of Tantalus 103
Imitative Diving Bell 103
The Water-proof Sieve 104
More than full 104
To cause Wine and Water to change places 104
Pyramid of Alum 104
Visible Vibration 105
Charcoal in Sugar 106
Floating Needles 106
Water in a Sling 106
Attraction in a Glass of Water 106
To prevent Cork floating in Water 107
Instantaneous Freezing 107
To freeze Water with Ether 107
Production of Nitre 108
Curious Transposition 108
Animal Barometer 108
Magic Soap 108
Equal Pressure of Water 109
To empty a Glass under Water 109
To empty a Glass of Water without touching it 109
Decomposition of Water 110
Water heavier than Wine 110
To inflate a Bladder without Air 110
Air and Water Balloon 110
Heated Air Balloon 111
The Pneumatic Tinder-box 111
The Bacchus Experiment 111
The Mysterious Circles 112
Prince Rupert’s Drops 114
Vegetable Hygrometer 114
The Pneumatic Dancer 115
The Ascending Snake 116
The Pneumatic Phial 116
Resin Bubbles 117
Moisture of the Atmosphere 117
Climates of a Room 117
Bubbles in Champagne 118
Proofs that Air is a heavy Fluid 118
To support a Pea on Air 119
Pyrophorus, or Air-tinder 119
Beauty of a Soap-bubble 120
Why a Guinea falls more quickly than a Feather through the Air 121
Solidity of Air 122
Breathing and Smelling 122

Sleights and Subtleties.
The Ring and the Handkerchief 127
The Knotted Handkerchief 128
The Invisible Springs 130
The Miraculous Apple 131
The Self-balanced Pail 132
The Phantom at command 132
The Miraculous Shilling 134
The Locomotive Shilling 135
The Penetrative Sixpence 136
The Vanishing Sixpence 136
To make a Sixpence balance and spin on its edge on the
point of a Needle 137
The Multiplying Coin 137
The Magic Rat Trap 137
The Velocity of Motion 138
The Exploding Bubble 139
The Magic Picture 139
Artificial Lightning 140
Three objects discernible only with both Eyes 140
To tell by a Watch Dial the Hour when a Person intends to rise 140
To make a Ring suspend by a Thread, after the Thread has
been burned 141
To melt a piece of Money in a Walnut-shell without injuring
the Shell 141
The Magical Mirrors 142
The Enchanted Bottle 143
The Armed Apparition 143
To extract the Silver out of a Ring that is thickly Gilded,
so that the Gold may remain entire 144
Curious Experiment with a Glass of Water 144
A Luminous Bottle, which will show the Hour on a Watch in
the Dark 144
The Wonderful Hat 145
To bring a Person down upon a Feather 145
The Apparent Impossibility 146
An Omelet cooked in a Hat over the Flame of a Candle 146
The Impossible Omelet 147
Go if you can 147
The Figure Puzzle 147
The Visible Invisible 147
The Double Meaning 148
Quite tired out 148
Something out of the Common 148
To rub one Sixpence into two 149
Magic Circle 149

Melange.
Illusions of Touch 153
Illusion of the Taste 154
The General Bleacher 154
Influence of coloured Glass on bulbous Roots 155
The Spinning-top “asleep” 155
To judge of Weights 156
Quicksilver and Oil united 156
To dissolve the Soda in Glass 156
Waterproof Paper 157
To Dissolve Gold or Platinum 157
Colder than Ice 157
Contra-crystallization 157
One and one do not make two 158
To copy Writing instantly 158
The Rival Dials 158
To spin Indian Rubber 158
Indelible Writing 159
Vegetable Anatomy 159
To tell what o’Clock it is by the Moon 160
The Physiognotype 161
Infinite Divisibility of Matter 161
Holding the Breath 162
Sand in the Hour-Glass 162
Resistance of Sand 163
Glass broken by Sand 164
To bleach Ivory 164
Vanishing Shells 164
The Magic Egg 164
The Magic Whirlpool 165
Magic Porcelain 167
A Galvanic Tongue 168
Drinking Porter out of Pewter 168
Electric or Galvanic Preservation 168
Light from the Diamond 169
To break a Stone with a blow of the Fist 169
Mimic Frost-work 169
To melt Lead in a piece of Paper 170
Hydrostatic Balance 170
Metallic Reduction 171
Electrical Attraction and Repulsion 171
Alchemical Electricity 172
The Electric Balls 173
The Electric Dance 173
Electric Light 173
Electric Light from Brown Paper 174
Sudden Production of Light 174
Electricity of the Cat 174

TRANSMUTATIONS.

THE SPECTRAL LAMP.

MIX some common salt with spirit of wine in a platinum or metallic cup; set the cup upon a wire frame over a spirit-lamp, which should be inclosed on each side, or in a dark-lantern: when the cup becomes heated, and the spirit ignited, it will burn with a strong yellow flame; if, however, it should not be perfectly yellow, throw more salt into the cup. The lamp being thus prepared, all other lights should be extinguished, and the yellow lamp introduced, when an appalling change will be exhibited; all the objects in the room will be but of one colour, and the complexions of the several persons, whether old or young, fair or brunette, will be metamorphosed to a ghastly, death-like yellow; whilst the gayest dresses, as the brightest crimson, the choicest lilac, the most vivid blue or green—all will be changed into one monotony of yellow: each person will be inclined to laugh at his neighbour, himself insensible of being one of the spectral company.

Their astonishment may be heightened by removing the yellow light to one end of the room, and restoring the usual or white light at the other; when one side of each person’s dress will resume its original colour, while the other will remain yellow; one cheek may bear the bloom of health, and the other, the yellow of jaundice. Or if, when the yellow light only is burning, the white light be introduced within a wire sieve, the company and the objects in the apartment will appear yellow, mottled with white.

Red light may be produced by mixing with the spirit in the cup over the lamp, salt of strontian instead of common salt; and the effect of the white or yellow lights, if introduced through a sieve upon the red light, will be even more striking than the white upon the yellow light.

CURIOUS CHANGE OF COLOURS.

Let there be no other light than a taper in the room; then put on a pair of dark green spectacles, and having closed one eye, view the taper with the other. Suddenly remove the spectacles, and the taper will assume a bright red appearance; but, if the spectacles be instantly replaced, the eye will be unable to distinguish any thing for a second or two. The order of colours will, therefore, be as follows:—green, red, green, black.

THE PROTEAN LIGHT.

Soak a cotton wick in a strong solution of salt and water, dry it, place it in a spirit lamp, and, when lit, it will give a bright yellow light for a long time. If you look through a piece of blue glass at the flame, it will lose all its yellow light, and you will only perceive feeble violet rays. If, before the blue glass, you place a pale yellow glass, the lamp will be absolutely invisible, though a candle may be distinctly seen through the same glasses.

THE CHAMELEON FLOWERS.

Trim a spirit-lamp, add a little salt to the wick, and light it. Set near it, a scarlet geranium, and the flower will appear yellow. Purple colours, in the same light, appear blue.

TO CHANGE THE COLOURS OF FLOWERS.

Hold over a lighted match, a purple columbine, or a blue larkspur, and it will change first to pink, and then to black. The yellow of other flowers, held as above, will continue unchanged. Thus, the purple tint will instantly disappear from a heart’s-ease, but the yellow will remain; and the yellow of a wall-flower will continue the same, though the brown streak will be discharged. If a scarlet, crimson, or maroon dahlia be tried, the colour will change to yellow; a fact known to gardeners, who by this mode, variegate their growing dahlias.

CHANGES OF THE POPPY.

Some flowers which are red, become blue by merely bruising them. Thus, if the petals of the common corn-poppy be rubbed upon white paper, they will stain it purple, which may be made green by washing it over with a strong solution of potash in water. Put poppy petals into very dilute muriatic acid, and the infusion will be of a florid red colour; by adding a little chalk, it will become the colour of port wine; and this tint, by the addition of potash, may be changed to green or yellow.

TO CHANGE THE COLOUR OF A ROSE.

Hold a red rose over the blue flame of a common match, and the colour will be discharged wherever the fume touches the leaves of the flower, so as to render it beautifully variegated, or entirely white. If it be then dipped into water, the redness, after a time, will be restored.

LIGHT CHANGING WHITE INTO BLACK.

Write upon linen with permanent ink, (which is a strong solution of nitrate of silver,) and the characters will be scarcely visible; remove the linen into a dark room, and they will not change; but expose them to a strong light, and they will be indelibly black.

THE VISIBLY GROWING ACORN.

Cut a circular piece of card to fit the top of a hyacinth glass, so as to rest upon the ledge, and exclude the air. Pierce a hole through the centre of the card, and pass through it a strong thread, having a small piece of wood tied to one end, which, resting transversely on the card, prevents its being drawn through. To the other end of the thread attach an acorn; and, having half filled the glass with water, suspend the acorn at a short distance from the surface.

The glass must be kept in a warm room; and, in a few days, the steam which has generated in the glass will hang from the acorn in a large drop. Shortly afterwards, the acorn will burst, the root will protrude and thrust itself into the water; and, in a few days more, a stem will shoot out at the other end, and, rising upwards, will press against the card, in which an orifice must be made to allow it to pass through. From this stem, small leaves will soon be observed to sprout; and, in the course of a few weeks, you will have a handsome oak plant, several inches in height.

CHANGES IN SAP GREEN.

Sap green is the inspissated juice of the buckthorn berries: if a little carbonate of soda be dropped into it, the colour will be changed from green to yellow; it may be reddened by acids, and its green colour restored by chalk.

TO REVIVE APPARENTLY DEAD PLANTS.

Make a strong dilution of camphor in spirit of wine, which add to soft water, in the proportion of a dram to a pint. If withered, or apparently dead plants be put into this liquid, and allowed to remain therein from two to three hours, they will revive.

SINGULAR EFFECT OF TEARS.

If tears are dropped on a dry piece of paper, stained with the juice of the petals of mallows or violets, they will change the paper to a permanently green colour.

BEAUTIES OF CRYSTALLIZATION.

Dissolve alum in hot water until no more can be dissolved in it; place in it a smooth glass rod and a stick of the same size; next day, the stick will be found covered with crystals, but the glass rod will be free from them: in this case, the crystals cling to the rough surface of the stick, but have no hold upon the smooth surface of the glass rod. But, if the rod be roughened with a file at certain intervals, and then placed in the alum and water, the crystals will adhere to the rough surfaces, and leave the smooth bright and clear.

Tie some threads of lamp-cotton irregularly around a copper wire or glass rod; place it in a hot solution of blue vitriol, strong as above, and the threads will be covered with beautiful blue crystals, while the glass rod will be bare.

Bore a hole through a piece of coke, and suspend it by a string from a stick, placed across a hot solution of alum; it will float; but, as it becomes loaded with crystals, it will sink in the solution according to the length of the string. Gas-coke has mostly a smooth, shining, and almost metallic surface, which the crystals will avoid, while they will cling only to the most irregular and porous parts.

If powdered tumeric be added to the hot solution of alum, the crystals will be of a bright yellow; litmus will cause them to be of a bright red; logwood will yield purple; and common writing ink, black; and the more muddy the solution, the finer will be the crystals.

To keep coloured alumn crystals from breaking, or losing their colour, place them under a glass shade with a saucer of water; this will preserve the atmosphere moist, and prevent the crystals getting too dry.

If crystals be formed on wire, they will be liable to break off, from the expansion and contraction of the wire by changes of temperature.

TO CRYSTALLIZE CAMPHOR.

Dissolve camphor in spirit of wine, moderately heated, until the spirit will not dissolve any more; pour some of the solution into a cold glass, and the camphor will instantly crystallize in beautiful tree-like forms, such as we see in the show-glasses of camphor in druggists’ windows.

CRYSTALLIZED TIN.

Mix half an ounce of nitric acid, six drams of muriatic acid, and two ounces of water; pour the mixture upon a piece of tin plate previously made hot, and, after washing it in the mixture, it will bear a beautiful crystalline surface, in feathery forms. This is the celebrated _moirée metallique_, and, when varnished, is made into ornamental boxes, &c. The figures will vary according to the degree of heat previously given to the metal.

CRYSTALS IN HARD WATER.

Hold in a wine-glass of hard water, a crystal of oxalic acid, and white threads will instantly descend through the liquid, suspended from the crystal.

VARIETIES OF CRYSTALS.

Make distinct solutions of common salt, nitre, and alum; set them in three saucers in any warm place, and let part of the water dry away or evaporate; then remove them to a warm room. The particles of the salts in each saucer will begin to attract each other, and form crystals, but not all of the same figure: the common salt will yield crystals with six square and equal faces, or sides; the nitre, six-sided crystals; and the alum, eight-sided crystals; and if these crystals be dissolved over and over again, they will always appear in the same forms.

HEAT FROM CRYSTALLIZATION.

Make a strong solution of Epsom salts in hot water, and while warm, bottle it, cork it closely, and it will remain liquid: draw out the cork, when the salts will immediately crystallize, and in the process, the remaining liquid and the bottle will become very warm.

SPLENDID SUBLIMATION.

Put into a flask a small portion of iodine; hold the flask over the flame of a spirit-lamp, and, from the state of rich ruby crystals, the iodine, on being heated, will become a ruby-coloured transparent gas; but, in cooling, will resume its crystalline form.

ARTIFICIAL ICE.

Mix four ounces of nitrate of ammonia, and four ounces of subcarbonate of soda, with four ounces of water, in a tin vessel, and in three hours the mixture will produce ten ounces of ice.

MAGIC INKS.

Dissolve oxide of cobalt in acetic acid, to which add a little nitre; write with this solution, hold the writing to the fire, and it will be of a pale rose colour, which will disappear on cooling.

Dissolve equal parts of sulphate of copper and muriate of ammonia in water; write with the solution, and it will give a yellow colour when heated, which will disappear when cold.

Dissolve nitrate of bismuth in water; write with the solution, and the characters will be invisible when dry, but will become legible on immersion in water.

Dissolve, in water, muriate of cobalt, which is of a bluish-green colour, and the solution will be pink; write with it, and the characters will be scarcely visible; but, if gently heated, they will appear in brilliant green, which will disappear as the paper cools.

CHAMELEON LIQUIDS.

Put a small portion of the compound called mineral chameleon into several glasses, pour upon each water at different temperatures, and the contents of each glass will exhibit a different shade of colour. A very hot solution will be of a beautiful green colour; a cold one, a deep purple.

Make a colourless solution of sulphate of copper; add to it a little ammonia, equally colourless, and the mixture will be of an intense blue colour; add to it a little sulphuric acid, and the blue colour will disappear; pour in a little solution of caustic ammonia, and the blue colour will be restored. Thus, may the liquor be thrice changed at pleasure.

THE MAGIC DYES.

Dissolve indigo in diluted sulphuric acid, and add to it an equal quantity of solution of carbonate of potass. If a piece of white cloth be dipped in the mixture, it will be changed to blue; yellow cloth, in the same mixture, may be changed to green; red to purple, and blue litmus paper to red.

Nearly fill a wine-glass with the juice of beet-root, which is of a deep red colour; add a little lime water, and the mixture will be colourless; dip into it a piece of white cloth, dry it rapidly, and in a few hours, the cloth will become red.

WINE CHANGED INTO WATER.

Mix a little solution of subacetate of lead with port wine; filter the mixture through blotting paper, and a colourless liquid will pass through; to this add a small quantity of dry salt of tartar, when a spirit will rise, which may be inflamed on the surface of the water.

TWO COLOURLESS TRANSPARENT LIQUIDS BECOME BLACK AND OPAQUE.

Have in one vessel some sulphuric acid, and in another an infusion of nut-galls; they are both colourless and transparent; mix them, and they will become black and opaque.

TWO COLOURLESS FLUIDS MAKE A COLOURED ONE.

Put into a wine-glass of water, a few drops of prussiate of potash; and into a second glass of water, a little weak solution of sulphate of iron in water: pour the colourless mixtures together into a tumbler, and they will be immediately changed to a bright deep blue colour.

Or, mix the solution of prussiate of potash with that of nitrate of bismuth, and a yellow will be the product.

Or, mix the solution of prussiate of potash with that of sulphate of copper, and the mixture will be of a reddish brown colour.

CHANGE OF COLOUR BY COLOURLESS FLUIDS.

Three different colours may be produced from the same infusion, merely by the addition of three colourless fluids. Slice a little red cabbage, pour boiling water upon it, and when cold, decant the clear infusion, which divide into three wine-glasses: to one, add a small quantity of solution of alum in water; to the second, a little solution of potash in water; and to the third, a few drops of muriatic acid. The liquor in the first glass will assume a purple colour, the second, a bright green, and the third a rich crimson.

Put a dram of powdered nitrate of cobalt into a phial containing an ounce of the solution of caustic potass; cork the phial, and the liquid will assume a blue colour, next a lilac, afterwards a peach colour, and lastly a light red.

TO CHANGE A BLUE LIQUID TO WHITE.

Dissolve a small lump of indigo in sulphuric acid, by the aid of moderate heat, and you will obtain an intense blue colour: add a drop of this to half a pint of water, so as to dilute the blue; then pour some of it into strong chloride of lime, and the blue will be bleached with almost magical velocity.

VERITABLE “BLACK” TEA.

Make a cup of strong green tea; dissolve a little green copperas in water, which add to the tea, and its colour will be black.

RESTORATION OF COLOUR BY WATER.

Water being a colourless fluid, ought, one would imagine, when mixed with other substances of no decided colour, to produce a colourless compound. Nevertheless, it is to water only that blue vitriol, or sulphate of copper, owes its vivid blueness; as will be plainly evinced by the following simple experiment. Heat a few crystals of the vitriol in a fire shovel, pulverize them, and the powder will be of a dull and dirty white appearance. Pour a little water upon this, when a slight hissing noise will be heard, and at the same moment, the blue colour will instantly re-appear.

Under the microscope, the beauty of this experiment will be increased, for the instant that a drop of water is placed in contact with the vitriol, the powder may be seen to shoot into blue prisms. If a crystal of prussiate of potash be similarly heated, its yellow colour will vanish, but re-appear on being dropped into water.

THE MAGIC WRITING.

Dissolve a small portion of green-copperas in water, and soak in it sheets of writing paper, so as to allow them to be taken out whole, and then dried; then, cover the paper with very finely powdered galls, and write on it with a pen dipped in water; when dry, brush off the galls, and the writing will appear.

TWO LIQUIDS MAKE A SOLID.

Dissolve muriate of lime in water until it will dissolve no more; make also a similar solution of carbonate of potash; both will be transparent fluids; but if equal quantities of each be mixed and stirred together, they will become a solid mass.

TWO SOLIDS MAKE A LIQUID.

Rub together in a mortar, equal quantities of the crystals of Glauber’s salts and nitrate of ammonia, and the two salts will slowly become a liquid.

A SOLID OPAQUE MASS MADE A TRANSPARENT LIQUID.

Take the solid mixture of the solutions of muriate of lime and carbonate of potash, pour upon it a very little nitric acid, and the solid opaque mass will be changed to a transparent liquid.

TWO COLD LIQUIDS MAKE A HOT ONE.

Mix four drams of sulphuric acid, (oil of vitrol,) with one dram of cold water, suddenly, in a cup, and the mixture will be nearly half as hot again as boiling water.

QUADRUPLE TRANSMUTATION.

Dissolve a small piece of nickel in nitric acid, and it will appear of a fine grass-green colour; add to it a little ammonia, and a blue precipitate will be formed; this will change to a purple-red in a few hours, and the addition of any acid will convert it to an apple-green.

QUINTUPLE TRANSMUTATION.

Heat potassium over the flame of a spirit-lamp, and the colour will change from white to a bright azure, thence to a bright blue, green, and olive.

COMBINATION OF COLOURS.

Cut out a disc or circle of pasteboard, and cover it with paper half green and half black: cause the disc to be rapidly turned round, (like the shafts of a toy wind-mill,) and the colours will combine and produce white.

UNION OF TWO METALS WITHOUT HEAT.

Cut a circular piece of gold-leaf, called “dentist’s gold,” about half an inch in diameter; drop upon it a globule of mercury, about the size of a small pea, and if they be left for a short time, the gold will lose its solidity and yellow colour, and the mercury its liquid form, making a soft mass, of the colour of mercury.

MAGIC BREATH.

Half fill a glass tumbler with lime-water; breathe into it frequently, at the same time stirring it with a piece of glass. The fluid, which before was perfectly transparent, will presently become quite white, and, if allowed to remain at rest, real chalk will be deposited.

TWO BITTERS MAKE A SWEET.

It has been discovered, that a mixture of nitrate of silver with hypo-sulphate of soda, both of which are remarkably bitter, will produce the sweetest known substance.

VISIBLE AND INVISIBLE.

Write with French chalk on a looking-glass; wipe it with a handkerchief, and the lines will disappear; breathe on it, and they will re-appear. This alteration will take place for a great number of times, and after the lapse of a considerable period.

SIGHT AND SOUND.

ARTIFICIAL MIRAGE.

THE mirage is an optical phenomenon, produced by the refractive power of the atmosphere. The appearance presented is that of the double image of an object in the air; one of the images being in the natural position, and the other inverted, so as to resemble a natural object and its image in the water. The mirage is commonly vertical, or upright, that is, presenting the appearance, above described, of one object over another, like a ship above its shadow in the water. Sometimes, however, the image is horizontal, or upon the water, and at other times, it is seen on the right or left hand of the real object, or on both sides.

All the effects of the mirage may be represented artificially to the eye. For this purpose, provide a glass tumbler two-thirds full of water, and pour spirit of wine upon it; or pour into a tumbler some syrup, and fill it up with water: as the water and spirit, or the syrup and water incorporate, they will produce a refractive power; then, by looking through the mixed or intermediate liquids at any object held behind the tumblers, its inverted image may be seen. The same effect, Dr. Walloston has shown, may be produced, by looking along the side of a red-hot poker at a word or object ten or twelve feet distant. At a distance less than three-eighths of an inch from the line of the poker, an inverted image was seen; and within and without that, an erect image.

The above phenomena may likewise be illustrated, by holding a heated iron above a tumbler of water, until the whole becomes changed; then withdraw the iron, and, through the water, the phenomena of the mirage may be seen in the finest manner.

Or, look directly above the flame of a candle, or over the glass of a lighted lamp, and a tremulous motion may be observed; because the warm air rises, and its refracting power being less than that of the colder air, the currents are rendered visible by the distortion of objects viewed through them. The same effect is observable over chimney pots, and slated roofs which have been heated by the sun.

MOTION OF THE EYE.

On entering a room, we imagine that we see the whole side of it at once, as the cornice, the pattern of the paper-hanging, pictures, chairs, &c., but we are deceived; for each object is rapidly, but singly presented to the eye, by its constant motion. If the eye were steady, vision would be lost. For example, fix the eye on one point, and you will find the whole scene become more and more obscure, till it vanishes. Then, if you change the direction of the eye ever so little, at once the whole scene will be again perfect before you.

SINGLE VISION WITH TWO EYES.

As we have two eyes, and a separate image of every external object is formed in each, it may be asked, why do we not see double? The answer is, it is a matter of habit. Habit alone teaches us, that the sensations of sight correspond to any thing external, and shows to what they correspond. Thus, place a wafer on a table before you; direct your eyes to it, that is, bring its image on both retinæ to those parts which habit has ascertained to be the most sensible, and best situated for seeing distinctly, and you will see only the _single wafer_. But, while looking at the wafer, squeeze the upper part of one eye downwards, by pressing on the eyelid with the finger, and thereby forcibly throw the image on another part of the retina of that eye, and double vision will be immediately produced; that is, _two wafers_ will be distinctly seen, which will appear to recede from each other as the pressure is stronger, and approach, and finally blend into one, as it is relieved. The same effect maybe produced without pressure, by directing the eyes to a point nearer to, or farther from them, than the wafer; the optic axes, in this case, being both directed away from the object seen.

TWO OBJECTS SEEN AS ONE.

On a sheet of black paper, or other dark ground, place two white wafers, having their centres three inches distant. Vertically above the paper, and to the _left_, look with the _right_ eye, at twelve inches from it, and so that, when looking down on it, the line joining the two eyes shall be parallel to that joining the centre of the wafers. In this situation, close the left eye, and look full with the right perpendicularly at the wafer below it, when this wafer only will be seen, the other being completely invisible. But, if it be removed ever so little from its place, either to the right or left, above or below, it will become immediately visible, and start, as it were, into existence. The distances here set down may, perhaps, vary slightly in different eyes.

Upon this curious effect, Sir John Herschel observes: “It will cease to be thought singular, that this fact of the absolute invisibility of objects in a certain point of the field of view of each eye, should be one of which not one person in ten thousand is apprised, when we learn, that it is not extremely uncommon to find persons who have for some time been totally blind with one eye, without being aware of the fact.”

ONLY ONE OBJECT CAN BE SEEN AT A TIME.

Look at the pattern of the paper-hanging of a room, a picture, or almost any other object in it; then, without altering your position, call to mind the magnificent dome of St. Paul’s Cathedral; the pattern of the paper-hanging, or the subject of the picture, though actually impressed on the retina of the eye, will be momentarily lost sight of by the mind; and, during the instant, the recollected image of the dome rising from the dingy roofs of London, will be distinctly seen, but in indistinct colouring and outline. When the object of the recollection is answered, the dome will quickly disappear, and the paper-hanging pattern, or the picture, again resume the ascendancy.

STRAIGHT OBJECTS SEEN CROOKED.

Look through a series of vertical bars, as those of a palisade, or of a Venetian window-blind, at the wheel of a carriage passing along the street, and the spokes of the wheel, instead of appearing straight, as they naturally would do, if no bars intervened, seem to be of a curved form. The velocity of the wheel must not be so great as to prevent the eye from following the spokes as they revolve.

Again, when the disk of the wheel, instead of being marked by a number of radiant lines, has only one radius marked upon it, it presents the appearance, when rolled behind the bars, of a number of radii, each having the curvature corresponding to its situation, their number being the same as that of the bars through which you look at the wheel. It is, therefore, evident that the several portions of one and the same line, seen through the intervals of the bars, form on the retina of the eye so many different radii.

OPTICAL ILLUSION.

Shut one eye, direct the other to any fixed point, as the head of a pin, and you will indistinctly see all other objects. Suppose one of these to be a strip of white paper, or a pen lying upon a table covered with a green cloth: either of them will disappear altogether, as if taken off the table; for the impression of the green cloth will entirely extend itself over that part of the retina which the image of the pen occupied. The vanished pen will, however, shortly re-appear, and again vanish; and the same effect will take place when both eyes are open, though not so readily as with one eye.

PIN-HOLE FOCUS.

Make a pin-hole in a card, which hold between a candle and a piece of white paper, in a dark room, when an exact representation of the flame, but inverted, will be seen depicted upon the paper, and be enlarged as the paper is drawn from the hole; and if, in a dark room, a white screen or sheet of paper be extended at a few feet from a small round hole, an exact picture of all external objects, of their natural colours and forms, will be seen traced on the screen; moving objects being represented in motion, and stationary ones at rest.

OPTICAL DECEPTIONS.

Prick a hole in a card with a needle; place the same needle near the eye, in a line with the card-hole, look by daylight at the end of the needle, and it will appear to be behind the card, and reversed.

Prick a hole with a pin in a black card, place it very near the eye, look through it at any small object, and it will appear larger as it is nearer the eye; while, if we observe it without the card, it will appear sensibly of the same magnitude at all parts of the room.

ACCURACY OF SIGHT.

Rule a short line upon a slate, and upon another slate rule another line, one-eleventh longer than the first: a person possessing what is called “a true eye,” may perceive the difference in length, even though fifty or sixty seconds elapse between looking at the first and the second lines. If they differ only one-twentieth, then an interval of thirty-five seconds may elapse without destroying the judgment; but, if it be longer, the estimate will be incorrect. When the difference between the lines amounts only to one-fiftieth, an interval of three seconds between the examination of each, is the longest that can be allowed without interfering with the correctness of the comparison.

VISUAL DECEPTION.

Let a room be only lit by the feeble gleam of a fire, almost extinguished, and the eye will see with difficulty the objects in the apartment, from the small degree of light with which they happen to be illuminated. The more exertion is made to ascertain what these objects are, as by fixing the eye more steadily upon them, the greater will be the difficulty in accomplishing it. The eye will be painfully agitated, the object will swell and contract, and partly disappear, but will again become visible when the eye has recovered from its delirium.

HAND-WRITING UPON THE WALL.

Cut the word or words to be shown, out of a thick card or pasteboard, place it before a lighted lamp, and the writing will be distinctly seen upon the wall of the apartment.

IMITATIVE HALOES.

Look at a candle, or any other luminous body, through a plate of glass, covered with vapour, or dust in a finely divided state, and it will be surrounded with a ring of colours, like a halo round the sun or moon. These rings increase with the size of the particles which produce them; and their brilliancy and number depend on the uniform size of these particles.

Or, haloes may be imitated by crystallizing various salts upon thin plates of glass, and looking through the plate at a candle or the sun. For example, spread a few drops of a strong solution of alum over a plate of glass so as to crystallize quickly, and cover it with a crust scarcely visible to the eye. Then place the eye close behind the smooth side of the glass plate, look through it at a candle, and you will perceive three fine haloes at different distances, encircling the flame.

TO READ A COIN IN THE DARK.

By the following simple method, the legend or inscription upon a coin may be read in absolute darkness. Polish the surface of any silver coin as highly as possible; touch the raised parts with aqua-fortis, so as to make them rough, taking care that the parts not raised retain their polish. Place the coin thus prepared upon red-hot iron, remove it into a dark room, and the figure and inscription will become more luminous than the rest, and may be distinctly seen and read by the spectator. If the lower parts of the coin be roughened with the acid, and the raised parts be polished, the effect will be reversed, and the figure and inscription will appear dark, or black upon a light or white ground.

This experiment will be more surprising if made with an old coin, from which the figure and inscription have been obliterated; for, when the coin is placed upon the red-hot iron, the figure and inscription may be distinctly read upon a surface which had hitherto appeared blank.

This experiment may be made with small coins upon a heated poker, a flat iron, or a salamander. The effect will be more perfect if the red-hot iron be concealed from the eye of the spectator: this may be done by placing upon the iron a piece of blackened tin, with a hole cut out, the size of the coin to be heated.

TO MAKE A PRISM.

Provide two small pieces of window-glass and a lump of wax. Soften and mould the wax, stick the two pieces of glass upon it, so that they meet, as in the cut, where _w_ is the wax, _g_ and _g_ the glasses stuck to it, (Fig. 1.) The end view (Fig. 2) will show the angle, _a_, at which the pieces of glass meet; into which angle put a drop of water.

To use the instrument thus made, make a small hole, or a narrow horizontal slit, so that you can see the sky through it, when you stand at some distance from it in the room. Or a piece of pasteboard placed in the upper part of the window-sash, with a slit cut in it, will serve the purpose of the hole in the shutter. The slit should be about one-tenth of an inch wide, and an inch or two long, with even edges. Then hold the prism in your hand, place it close to your eye, and look through the drop of water, when you will see a beautiful train of colours, called a spectrum; at one end red, at the other violet, and in the middle yellowish green.

The annexed figure will better explain the direction in which to look: here, _e_, is the eye of the spectator, _p_, is the prism, _h_, the hole in the shutter or pasteboard, _s_, the spectrum. By a little practice, you will soon become accustomed to look in the right direction, and will see the colours very bright and distinct.

By means of this simple contrivance, white light may be analysed and proved to consist of coloured rays, and several of its properties be beautifully illustrated.

OPTICAL AUGMENTATION.

Take a glass rummer that is narrow at bottom and wide at top, into which put a half-sovereign, and fill the glass three-fourths with water; place on it a piece of paper, and then a plate, and turn the glass upside down quickly, that the water may not escape: by looking sideways at the glass, you will perceive a sovereign at the bottom, and higher up the half-sovereign, floating near the surface. Fill the glass with water, and the large piece only will be visible.

GOLD FISH IN A GLASS GLOBE.

A single gold fish in a globe vase, is often mistaken for two fishes, because it is seen as well by the light bent through the upper surface of the water, as by straight rays passing through the side of the vase.

COLOURS PRODUCED BY THE UNEQUAL ACTION OF LIGHT UPON THE EYES.

If we hold a slip of white paper vertically, about a foot from the eye, and direct both eyes to an object at some distance beyond it, so as to see the slip of paper double, then, when a candle is brought near the right eye, so as to act strongly upon it, while the left eye is protected from its light, the left-hand slip of paper will be of a tolerably bright _green_ colour, while the right-hand slip of paper, seen by the left eye, will be of a red colour. If the one image overlaps the other, the colour of the overlapping parts will be white, arising from a mixture of the complementary red and green. When equal candles are held equally near to each eye, each of the images of the slip of paper is white. If, when the paper is seen red and green by holding the candle to the right eye, we quickly take it to the left eye, we shall find that the left image of the slip of paper gradually changes from _green_ to _red_, and the right one from _red_ to _green_, both of them having the same tint during the time that the change is going on.

OPTICAL DECEPTION.

Look steadily at a carpet having figures of one colour, green, for example, upon a ground of another colour, suppose red, and you will sometimes see the whole of the green pattern as if the red one were obliterated; and at other times, you will see the whole of the red pattern, as if the green one were obliterated. The former effect takes place when the eye is steadily fixed on the green part, and the latter, when it is steadily fixed on the red portion.

COLOURED SHADOWS.

Provide two lighted candles, and place them upon a table before a whitewashed or light papered wall: hold before one of the candles a piece of coloured glass, taking care to remove to a greater distance the candle before which the coloured glass is not placed, in order to equalize the darkness of the two shadows. If you use a piece of green glass, one of the shadows will be green, and the other a fine red; if you use blue glass, one of the shadows will be blue, and the other a pale yellow.

COLOURS OF SCRATCHES.

An extremely fine scratch on a well-polished surface, may be regarded as having a concave, cylindrical, or, at least, a curved surface, capable of reflecting light in all directions; this is evident, for it is visible in all directions. Hence, a single scratch or furrow in a surface, may produce colours by the interference of the rays reflected from its opposite edges. Examine a spider’s thread in the sunshine, and it will gleam with vivid colours. These may arise from a similar cause, or from the thread itself, as spun by the animal, consisting of several threads agglutinated together, and thus presenting, not a cylindrical, but a furrowed surface.

OCULAR SPECTRA.

One of the most curious affections of the eye is that, in virtue of which it sees what are called _ocular spectra_, or accidental colours. If we place a red wafer on a sheet of white paper, and, closing one eye, keep the other directed for some time to the centre of the wafer, then, if we turn the same eye to another part of the paper, we shall see a green wafer, the colour of which will continue to grow fainter and fainter, as we continue to look at it.

By using differently coloured wafers, we obtain the following results:

WAFER. SPECIMEN.

Black White.
White Black.
Red Bluish Green.
Orange Blue.
Yellow Indigo.
Green Violet, with a little Red.
Blue Orange Red.
Indigo Orange Yellow.
Violet Bluish Green.

BEAUTIFUL COLOURS OF MOTHER-OF-PEARL.