Chapter III: Part 3

Pound, coarsely, some of the dark blue or the fetid variety of Derbyshire spar; heat it in a dark room, in a platinum spoon, over the low flame of a spirit-lamp, and the spar will shine with a beautiful purple tint.

Pounded swinestone, calcareous spar, and powdered quartz, will also give out light, if strewn upon a fire-shovel which has been heated red-hot, and has just ceased glowing.

A variety of fluor spar, found in granite in Siberia, will shine in the dark when warmed, with a remarkably strong phosphorescent light, increasing as the temperature is raised. The light augments when the spar is plunged into water; and in boiling water, the spar becomes so luminous that the letters of a printed book can be seen in a dark room near the glass containing it.

Another variety of fluor spar, also found in Siberia, is of a pale violet colour, and emits a white light merely by the heat of the hand; and when put into boiling water, it will give out a green light.

LIGHT FROM OYSTER-SHELLS.

Put oyster-shells into a common fire; burn them for about half an hour; then remove them into a dark room, when many of the shells will exhibit beautiful specimens of prismatic colours.

RINGS OF LIGHT IN CRYSTAL.

This is one of the most striking of optical exhibitions, and may be thus simply produced. Provide a sheet of clear ice, about an inch thick, frozen in still weather; let the light fall through the ice upon a pane of window-glass, or a polished table, and by placing a fragment of plate-glass near the eye as a reflector, the most beautiful rings of light may be observed.

TO STRIKE LIGHT WITH CANE.

Strike a piece of rattan cane with a steel, and it contains so much silex, or flint, that it will exhibit sparks of light in the dark.

CAUSE OF TRANSPARENCY.

Moisten a piece of paper, and it will appear more transparent than when in its natural state; the cause of which is as follows: a piece of dry paper has its pores obstructed with finely interwoven threads; these are broken by the liquor, which also fills the pores as so many small tubes, and permits the light to pass through it, whereas the dry threads had hitherto prevented its passage.

TRANSPARENCY OF GOLD.

All bodies are more or less transparent. Thus, though gold is one of the densest metals, yet, if a piece of the thinnest gold-leaf be held up to a candle, the light will pass through it; and, that it passes through the substance of the metal, and not through cracks or holes too small to be detected by the eye, is evident from the colour of the transmitted light, which is green.

TINT CHANGED BY THICKNESS.

Provide a piece of plain and polished smalt-blue glass, such as sugar-basins and finger glasses are made of. It should be of unequal thickness. Look through this glass at a strong light, as that from the crack of a window-shutter, in a darkened room, and, at the thinnest part, the colour will be purely blue. As the thickness increases, a purple tinge will come on, which will become more and more ruddy; and, if the glass be very thick, the colour will pass to a deep red.

SHADOWS MADE DARKER BY INCREASED LIGHT.

Hold a finger between a candle and the wall, and it will cast a shadow of a certain darkness; then place another candle in the same line with the other from the wall, and the shadow will appear doubly dark, although there will be more light in the room than before. Then separate the candles, and place them so as to produce two shadows of the finger, one partly overlapping the other, and that part will be of double darkness, as compared with the remainders.

MINIATURE THUNDER AND LIGHTNING.

To imitate thunder, provide a thin sheet of iron; hold it by one corner between the finger and thumb, and allow it to hang freely by its own weight. Then shake the hand horizontally, so as to agitate the corner in a direction at right angles to the surface of the sheet. Thus you may produce a great variety of sounds, from the deep growl of distant thunder to those loud claps which rattle in rapid succession immediately over our heads. The same effect may be produced by sheets of tinned iron, or tin-plate, and by thin plates of mica; but the sound is shorter and more acute.

Partial flashes of lightning, aurora borealis, &c., may be beautifully imitated by taking in a spoon about a dram of the seeds of lycopodium, and throwing them against a lighted candle, all other light being excluded from the room.

A similar effect may be produced, by laying some powdered resin on a piece of paper, and fillipping it with the finger against the flame of a candle.

THE BURNING GLASS.

If, when the sun shines brightly, a piece of paper be held in the focus of the rays drawn by the burning-glass, it will take fire. This experiment succeeds best with brown or any dark-coloured paper: for, though the glass will collect an equal number of rays upon white as upon coloured paper, the white paper reflects the rays instead of allowing them to enter it; hence, the white is not so soon burnt as the coloured paper, which absorbing more light than it reflects, soon becomes heated and takes fire.

MAGIC OF HEAT.

Melt a small quantity of the sulphate of potass and copper in a spoon over a spirit-lamp; it will be fused at a heat just below redness, and produce a liquid of a dark green colour. Remove the spoon from the flame, when the liquid will become a solid of a brilliant emerald-green colour, and so remain till its heat sinks nearly to that of boiling water, when suddenly a commotion will take place throughout the mass, beginning from the surface, and each atom, as if animated, will start up and separate itself from the rest, till, in a few moments, the whole will become a heap of powder.

REPULSION BY HEAT.

Provide two small pieces of glass; sprinkle a minute portion of sulphur upon one piece, lay thin slips of wood around it, and place upon it the other piece of glass. Move them slowly over the flame of a lamp or candle, and the sulphur will become sublimed, and form grey nebulous patches, which are very curious microscopic objects. Each cluster consists of thousands of transparent globules, imitating, in miniature, the nebulæ which we see figured in treatises on astronomy. By observing the largest particles, we shall find them to be flattened on one side. Being very transparent, each of them acts the part of a little lens, and forms in its focus the image of a distant light, which can be perceived even in the smaller globules, until it vanishes from minuteness. If they are examined again after a certain number of hours, the smaller globules will generally be found to have retained their transparency, while the larger ones will have become opaque, in consequence of the sulphur having undergone some internal spontaneous change. But the most remarkable circumstance attending this experiment is, that the globules are found adhering to the upper glass only; the reason of which is, that the upper glass is somewhat cooler than the lower one; by which means we see that the vapour of sulphur is very powerfully repelled by heated glass. The flattened form of the particles is owing to the force with which they endeavour to recede from the lower glass, and their consequent pressure against the surface of the upper one. This experiment is considered by its originator, Mr. H. F. Talbot, F. R. S., to be a satisfactory argument in favour of the repulsive power of heat.

HEAT PASSING THROUGH GLASS.

The following experiment is also by Mr. Talbot:—Heat a poker bright-red hot, and having opened a window, apply the poker quickly very near to the outside of a pane, and the hand to the inside; a strong heat will be felt at the instant, which will cease as soon as the poker is withdrawn, and may be again renewed, and made to cease as quickly as before. Now, it is well known, that if a piece of glass is so much warmed as to convey the impression of heat to the hand, it will retain some part of that heat for a minute or more; but, in this experiment, the heat will vanish in a moment. It will not, therefore, be the heated pane of glass that we shall feel, but heat which has come through the glass, in a free or radiant state.

METALS UNEQUALLY INFLUENCED BY HEAT.

All metals do not conduct heat at the same rate, as may be proved by holding in the flame of a candle at the same time, a piece of silver wire, and a piece of platina wire, when the silver wire will become too hot to hold, much sooner than the platina. Or, cut a cone of each wire, tip it with wax, and place it upon a heated plate, as (a fire shovel,) when the wax will melt at different periods.

SPONTANEOUS COMBUSTION.

Mix a little chlorate of potass with spirit of wine in a strong saucer; add a little sulphuric acid, and an orange vapour will arise and burst into flame.

INEQUALITY OF HEAT IN FIRE-IRONS.

Place before a brisk fire a set of polished fire-irons, and besides them a rough unpolished poker, such as is used in a kitchen, or instead of a bright poker. The polished irons will remain for a long time without becoming warmer than the temperature of the room, because the heat radiated from the fire is all reflected, or thrown off, by the polished surface of the irons, and none of it is absorbed. The rough poker will, however, become speedily hot, so as not to be used without inconvenience. Hence, the polish of fire-irons is not merely ornamental but useful.

EXPANSION OF METAL BY HEAT.

Provide an iron rod, and fit it exactly into a metal ring; heat the rod red-hot, and it will no longer enter the ring.

Observe an iron gate on a warm day, when it will shut with difficulty; whereas, it will shut loosely and easily on a cold day.

EVAPORATION OF A METAL.

Rub a globule of mercury upon a silver spoon, and the two metals will combine with a white appearance; heat the spoon carefully in the flame of a spirit-lamp, when the mercury will volatilize and disappear, and the spoon may then be polished until it recovers its usual lustre: if, however, the mercury be left for some time on the spoon, the solid texture of the silver will be destroyed throughout, and then the silver can only be recovered by heating it in a ladle.

A FLOATING METTLE ON FIRE.

Throw a small piece of that marvellous substance, potassium, into a basin of water, and it will swim upon the surface, and burn with a beautiful light, of a red colour mixed with violet. When moderately heated in the air, potassium takes fire, and burns with a red light.

HEAT AND COLD FROM FLANNEL.

Put a piece of ice into a basin, which wrap up in many folds of flannel, and the ice may be preserved for some time by the fireside.

ICE MELTED BY AIR.

If two pieces of ice be placed in a warm room, one of them may be made to melt much sooner than the other, by blowing on it with a pair of bellows.

TO HOLD A HOT TEA-KETTLE ON THE HAND.

Be sure that the bottom of the kettle is well covered with soot; when the water in it boils, remove it from the fire, and place it upon the palm of the hand; no inconvenience will be felt, as the soot will prevent the heat being transmitted, from the water within and the heated metal, to the hand.

INCOMBUSTIBLE LINEN.

Make a strong solution of borax in water, and steep in it linen, muslin, or any article of clothing; when dry, they cannot easily be inflamed.

THE BURNING CIRCLE.

Light a stick, and whirl it round with a rapid motion, when its burning end will produce a complete circle of light, although that end can only be in one part of the circle at the same instant. This is caused by the duration of the impression of light upon the retina. Another example is, that during the twinkling of the eye we never lose sight of the object we are viewing.

WATER OF DIFFERENT TEMPERATURES IN THE SAME VESSEL.

Of heat and cold, as of wit and madness, it may be said that “thin partitions do their bounds divide.” Thus, paint one-half of the surface of a tin-pot with a mixture of lamp-black and size, and leave the other half, or side, bright; fill the vessel with boiling water, and by dipping a thermometer, or even the finger, into it shortly after, it will be found to cool much more rapidly upon the blackened than upon the bright side of the pot.

WARMTH OF DIFFERENT COLOURS.

Place upon the surface of snow, as upon the window-sill, in bright daylight or sunshine, pieces of cloth of the same size and quality, but of different colours, black, blue, green, yellow, and white: the black cloth will soon melt the snow beneath it, and sink downwards; next the blue, and then the green; the yellow but slightly; but the snow beneath the white cloth will be as firm as at first.

SUBSTITUTE FOR FIRE.

Put into a cup a lump of quick-lime, fresh from the kiln, pour water upon it, and the heat will be very great. A pailful of quick-lime, if dipped in water, and shut closely into a box constructed for the purpose, will give out sufficient heat to warm a room, even in very cold weather.

GAS AND STEAM.

LAUGHING GAS.

THE above fanciful appellation has been given to nitrous oxide, from the very agreeable sensations excited by inhaling it. In its pure state it destroys animal life, but loses this noxious quality when inhaled, because it becomes blended with the atmospheric air which it meets in the lungs. This gas is made by putting three or four drams of nitrate of ammonia, in crystals, into a small glass retort, which being held over a spirit lamp, the crystals will melt, and the gas be evolved.

Having thus produced the gas, it is to be passed into a large bladder having a stop-cock; and when you are desirous of exhibiting its effects, you cause the person who wishes to experience them, to first exhale the atmospheric air from the lungs, and then quickly placing the cock in his mouth, you turn it, and bid him inhale the gas. Immediately, a sense of extraordinary cheerfulness, fanciful flights of imagination, an uncontrollable propensity to laughter, and a consciousness of being capable of great muscular exertion, supervene. It does not operate in exactly the same manner on all persons; but in most cases the sensations are agreeable, and have this important difference from those produced by wine or spirituous liquors, that they are not succeeded by any depression of mind.

THE LUMINOUS WAND.

Cover a long slip of wood, half-way, with sulphur, by immersion while in a melted state. Having prepared a jar of nitrous oxide gas, as in preceding experiments, light the sulphur, and plunge the wand into the jar. The gas will extinguish the flame. Withdraw the wand, light it again, and when the flame is very brilliant, immerse it again in the jar. It will this time burn with great splendour, and of a beautiful red colour.

TO MAKE CARBONIC ACID GAS.

Put about an ounce of marble in small lumps, into an eight ounce phial, with about an equal quantity of water; pour in a little muriatic acid, and carbonic acid gas will be evolved.

CARBONIC ACID GAS IN WINE OR BEER VESSELS.

The apparently empty or upper part of vessels in which wine or beer is working, is filled with this deleterious gas; for its great weight prevents its ascent from the fermenting liquid. A variety of striking but simple experiments may be made with the gas in this condition. Lighted paper, or a candle dipped into it, will be immediately extinguished; and the smoke remaining in the carbonic acid gas will render its surface visible, which may be thrown into waves by agitation, like water. In consequence of the great weight of the carbonic acid gas, it may be taken from a vat of fermenting liquor, in a jug or bottle, and in the latter, if well corked, it may be conveyed to great distances; or the gas may be drawn out of a vessel by a cock, like a liquid.

TO EXTINGUISH FLAME WITH GAS.

The effects produced by pouring carbonic acid gas from one vessel to another, have a very singular appearance: if a lighted candle be placed in a jar, and the gas be poured upon it, the flame will be extinguished in a few seconds, though the eye is incapable of distinguishing that anything is poured out.

EFFECT OF HYDROGEN ON THE VOICE.

Make a hole through a wine cork of sufficient size to admit a smaller cork; through which make another hole, and fix it into the larger one. Tie the corks thus fixed into the neck of a bullock’s bladder, previously exhausted of air; let a tube from a bottle generating hydrogen pass very tightly through the aperture in the small cork, and the gas will distend and fill the bladder. The instant it is full, withdraw the inner cork, and either prevent the escape of the gas by means of the thumb, or cork it closely, till the operator is ready to _breathe the gas_; to do which, he should put the open cork into his mouth, and take _one_ inspiration, when, on immediately speaking, his voice will be remarkably shrill. The effect will pass off in a few seconds.

MAGIC TAPER.

Provide a piece of copper wire, about ten inches long, and fix at one end of it a piece of wax taper: take a pint bottle of hydrogen, and place the mouth downwards; light the taper, introduce it into the bottle, and the gas will take fire, and burn slowly towards the mouth, where it is in contact with the air. If, however, the taper be passed up into the bottle, it will be extinguished; but, on gently withdrawing it through the burning hydrogen, the wick will be rekindled. This may be done several times in succession with the same portion of gas.

THE GAS CANDLE.

Provide a strong glass bottle which will contain about eight ounces, or half a pint, into which put a few pieces of zinc; then mix half an ounce of sulphuric acid with four ounces of water, and pour it into the bottle upon the zinc; fit the mouth closely with a cork, through which put a metal tube which ends upward in a fine opening: the mixture in the bottle will soon effervesce, and hydrogen gas will rise through the tube. When it has escaped for about a minute, apply a lighted paper to the tube, and the gas will burn like a candle, but with a pale flame. Its brightness may be increased to brilliance, by sifting over it a small quantity of magnesia.

GAS BUBBLES.

Provide a bladder, fill it with hydrogen gas, to be made as for the last experiment, and fit the end of a tobacco-pipe closely into the bladder; dip the bowl of the pipe into soap and water, and, by pressing the bladder, soap-bubbles will be formed, filled with hydrogen gas; which bubbles, or balloons, will rise in the air, and keep there for some time.

GAS-LIGHT IN THE DAY-TIME.

Light a stream of hydrogen gas, and it will be scarcely visible in the day-light; but place in it a small coil of platinum wire, or project a little oxide of zinc through the flame, and it will become very luminous.

MINIATURE BALLOONS.

One of the simplest and most beautiful experiments in aërostation, is to take a turkey’s maw, or stomach, properly prepared, and to fill it either with pure hydrogen gas, or the carburetted hydrogen produced from coal. If the balloon be then allowed to escape in the open air, it will ascend rapidly in the atmosphere: but the best method of showing the experiment, is to let the balloon off a high staircase, and observe it ascend to the cupola or light, where it will remain near the highest point till the escape of the gas allow it to descend. The prepared maw for this balloon may be purchased of any optician.

MINIATURE GAS-LIGHTING.

Bicarburetted hydrogen is the principal constituent of the gas burned in the streets: it is procured from coal, and the process may readily be performed on a small scale. Put about two ounces of pounded coal into an earthen retort, and fix a glass tube into the neck, terminating in an aperture of one-fifth of an inch in diameter; heat the retort red-hot, and apply the flame of a taper to the orifice of the tube, when the gas will burn with a bright white light, very different from that afforded by the combustion of hydrogen; a circumstance owing to the presence of particles of carbon in the carburet, which being intensely ignited, are highly luminous.

It is no less strange than true, that bicarburetted hydrogen, the substance which we so largely consume to illuminate our towns, is ether when united to water in one proportion, and spirit when combined with it in another; a fluid which constitutes the strength of all wines, beer, and fermented liquors.

MUSICAL GAS.

Into a half-pint glass bottle, put some zinc, granulated by being melted in a ladle, and then poured gradually into water. Add some sulphuric acid, diluted with eight parts by weight of water. Then pass a glass tube with a capillary bore, through a cork, which you have previously made to closely fit the bottle, and cork the bottle well. In a short time, the atmospheric air will be expelled, and hydrogen gas will rise through the tube; you then apply a light, and the gas will become ignited. If you now hold another glass tube, about eighteen or twenty inches long over the flame sufficiently wide to enclose the other tube very loosely (_see engraving_), the little speck of flame will sport along the larger tube, and musical sounds will be produced, which may be varied by using other tubes of different dimensions, and made of different materials; the wide tubes forming the lower, and the narrow tubes the upper notes.

MINIATURE WILL O’-THE-WISP.

Put a small piece or two of the phosphuret of lime into a saucer of water, when bubbles of phosphuretted hydrogen gas will rise to the surface, explode into flame, and cause a white smoke; representing, on a small scale, the _ignis fatuus_, or will o’-the-wisp, as seen over marshy ground, or stagnant pools of water.

PHOSPHORIC ILLUMINATION.

A light so brilliant that the eye can scarcely bear to contemplate it, is produced by the immersion of phosphorus in oxygen gas. To perform this experiment, you place a piece of phosphorus in a copper cup, of the circumference of a sixpence, which is fastened to a thick piece of iron wire, attached to a cork which fits a bottle (as in the foregoing experiment) filled with oxygen gas. Set fire to the phosphorous, and quickly plunge it into the bottle; when the splendour of the combustion will be surpassingly beautiful.

It is necessary to observe, that the heat is so excessive, that if the piece of phosphorous in this experiment be larger than a small pea, there will be great danger of breaking the bottle.

COMBUSTION OF IRON IN OXYGEN GAS.

Twist a piece of fine iron wire, such as is used by piano-forte makers, round a cylindrically-shaped piece of wood or metal, which will give it a spiral form; or a broken watch-spring, which may be bought for a trifle of the watch-makers, will answer the same purpose. Fasten round one end of it some waxed cotton thread or twine, and attach the other end to a cork, which fits a glass jar or bottle, that will hold a quart, filled with oxygen gas. Having made the wire red-hot by setting light to the thread, plunge it into the bottle. Do not cork the bottle, but let the cork merely lay on the mouth, and to prevent its being burned, a small a piece of lead should be fastened to the bottom of it. The iron will instantly begin to burn with great brilliancy, throwing out luminous scintillations.

To prevent the bottle from being broken by the sparks, a small quantity of sand should be previously poured into it.

GLOW-WORM IN OXYGEN GAS.

If a glow-worm be placed in a jar of oxygen gas, in a dark room, it will shine with a far surpassing brilliancy to that which it exhibits in atmospheric air.

LUMINOUS CHARCOAL.

Attach a small piece of charcoal to the end of a copper-wire; make it red-hot, and immerse it in a jar of oxygen gas. The charcoal will burn with great brilliance, throwing out splendid scintillations. The bark of the wood converted into charcoal must be selected, otherwise there will be no scintillations.

BRILLIANT COMBUSTION IN OXYGEN.

Place in a bottle of oxygen gas a lighted taper, and it will burn with a flame of increased brilliancy.

Extinguish the taper immediately; put it into the same or another bottle of oxygen, and it will be again lighted provided a spark remain on the wick.

Bend a piece of iron wire in a spiral form, and tie on to one end some cotton or flax; sprinkle some flour of sulphur on it, set it on fire, dip it into a bottle of oxygen gas, and beautiful corruscations will be thrown off the wire.

FLAME FROM COLD METALS.

Provide a bottle of the gas chlorine, which may be purchased of any operative chemist, and with it you may exhibit some brilliant experiments.

For example, reduce a small piece of the metal antimony to a very fine power in a mortar; place some of this on a bent card, then loosen the stopper of the bottle of chlorine, and throw in the antimony, it will take fire spontaneously, and burn with much splendour; thus exhibiting a cold metal spontaneously bursting into flame.

If, however, a _lump_ of antimony be dropped into the chlorine, there will be no spontaneous combustion, nor immediate change: but, in the course of time, the antimony will become incrusted with a white powder, and no chlorine will be found in the bottle.

Or, provide copper in fine leaves, known as “Dutch metal;” slightly breathe on one end of a glass rod, about ten inches long, and cause one or two leaves of the metal to adhere to the damp end; then open a bottle of chlorine, quickly plunge in the leaves, when they will instantly take fire, and burn with a fine red light, leaving in the bottle a greenish-yellow solid substance.

A small _lump_ of copper, or “Dutch metal,” will not burn as above, but will be slowly acted upon, like the antimony.

Immerse gold leaf in a jar of chlorine gas, and combustion with a beautiful green flame will take place.

PHOSPHORUS IN CHLORINE.

Put into a deflagrating spoon about four grains of phosphorus, and let it down into a bottle of chlorine, when the phosphorus will ignite instantaneously.

Or, fold a slip of blotting-paper into a match five inches long; dip it into oil of turpentine, drain it an instant, drop it into another bottle of chlorine, when it will burst into a flame, and deposit much carbon.

CAOUTCHOUC BALLOONS.

Put a little ether into a bottle of caoutchouc, close it tightly, soak it in hot water, and it will become inflated to a considerable size. These globes may be made so thin as to be transparent.

A piece of caoutchouc, the size of a walnut, has thus been extended to a ball fifteen inches in diameter; and a few years since, a caoutchouc balloon, thus made, escaped from Philadelphia, and was found 130 miles from that city.

TO INCREASE THE LIGHT OF COAL GAS.

Lay a piece of wire-gauze upon the glass chimney of a common argand gas burner, when the flame will be enlarged to twice its former dimensions, and its light fully doubled. If the experiment be made with a common argand oil-lamp, the flame will be often enlarged, but so discoloured as to yield less light.

GAS FROM INDIAN RUBBER.

Put caoutchoucine, or the spirit distilled from caoutchouc, or Indian rubber, into a phial, little more than sufficient to cover the bottom, and the remainder of the phial will be filled with a heavy vapour; pour this off the spirit into another phial, apply to it a piece of lighted paper, and the vapour will burn with a brilliant flame.

ETHER GAS.

Let fall a few drops of ether into a large drinking-glass, and cover it with a plate for a few minutes; during this time the glass will be filled with vapour from the ether, so that, on removing the plate, and applying a piece of lighted paper at the mouth of the glass, the invisible vapour will take fire; thus proving how readily a volatile fluid, such as ether, combines with the air.

MAGIC VAPOUR.

Provide a glass tube, about three feet long and half an inch in diameter, nearly fill it with water, upon the surface of which pour a little coloured ether; then close the open end of the tube carefully with the palm of the hand, invert it in a basin of water, and rest the tube against the wall: the ether will rise through the water to the upper end of the tube; pour a little hot water over the tube, and it will soon cause the ether to boil within, and its vapour may thus be made to drive nearly all the water out of the tube into the basin; if, however, you then cool the tube by pouring cold water over it, the vaporized ether will again become a liquid, and float upon the water as before.

GAS FROM THE UNION OF METALS.

Nearly fill a wine-glass with diluted sulphuric acid, and place in it a wire of silver and another of zinc, taking care that they do not touch each other; when the zinc will be changed by the acid, but the silver will remain inert. But, cause the upper ends of the wires to touch each other, and a stream of gas will issue from them.

INVISIBLE GASES MADE VISIBLE.

Pour a little sulphuric acid upon some common salt in a saucer. Into another saucer put a mixture of about two parts of quick-lime and one of sal ammoniac, both in powder, adding to these a very small quantity of boiling water. Each saucer apart will yield an invisible gas: but the moment they are brought closely together, very visible vapours will be the result.

LIGHT UNDER WATER.

Put into an _eau de Cologne_ bottle two drams of chlorate of potass, and upon that salt about a dozen chips of phosphorous, and fill up the bottle with cold water: provide a glass tube which will reach to the potass, through which pour half-an-ounce, by measure, of strong sulphuric acid, when a gas will instantly rise, give to the liquid a deep yellow colour, and inflame the phosphorous in a striking manner.

GASEOUS EVANESCENCE.

Add a tea-spoonful of fuming nitric acid to two tea-spoonfuls of spirit of wine, in a cup, and the liquids will presently disappear in the form of vapour.

VIOLET-COLOURED GAS.

Put three or four grains of iodine into a small clean Florence oil flask, and close it with a cork. Warm the flask gently over a candle, or before the fire, and the iodine will become converted into a beautiful violet-coloured vapour, which condenses again into brilliant metallic crystals, when the flask is suffered to become cold. The experiment may be repeated with the same flask for any number of times.

Or, upon a small sheet of any metal, place a few grains of iodine, and add a chip of dry phosphorous; when the latter will inflame, and the iodine pass off in a violet vapour.

TO COLLECT GASES.

Provide a moistened bladder, tie a piece of tobacco-pipe firmly into its neck, twisting it so as to expel the common air. This may be fitted to any vessel by means of the pipe, which may be fixed in the cork of a bottle containing gas, and closely luted with putty or clay, or powdered lime and white of egg.

THE DEFLAGRATING SPOON.

To introduce substances into gases, a deflagrating spoon is required. It may be bought for half-a-crown; but an instrument equally useful may be made as follows: cut a piece of sheet copper somewhat larger than a sixpence, and bend it into a shallow, cup-like form; twist four fine brass wires, each nine inches long, tightly together, leaving an inch at the extremities, which must be spread to hold the copper, as the strings or chains of a balance support the scale-pan. To complete it, take a piece of sheet-lead, the size of a penny-piece; make a hole through the centre large enough to admit the twisted wires, but, at the same time, retaining them firmly in their position: then, if the wires will not rest in the lead by adhesion, the hole may be enlarged, the wire put in, and secured by a piece of solder. The spoon being then let down through the mouth of a bottle, the circular piece of lead rests upon and stops the mouth.

WHAT IS STEAM?

Invert a glass goblet over a cup of hot water, when the vapour or steam will be seen to rise in it, to condense upon the cold glass, and then to run down its inside; thus showing that steam is vaporized water, and will, when the heat is abstracted from it, become water again.

THE STEAM-ENGINE SIMPLIFIED.

The steam-engine is much more intelligible than its name first suggests. That part by which the machinery is set in motion, may be compared to a syringe, or squirt, the rod of which is driven up and down by steam admitted above and below, one end of the rod being connected with the machinery to be worked. Thus, the piston is made to turn the wheels of a railway carriage, or the paddles of a steam-boat.

The elastic force of the steam, or vapour, by which the rod is driven up and down, may be explained by this simple experiment. Provide a test tube, put into it a little water, hold the thumb over the mouth, and cause the water to boil by holding it over a spirit-lamp. There will soon be felt a pressure against the thumb; when, if the tube be dipped into cold water, the thumb being still held at the end, a kind of suction will be felt against it. Now, the tube resembles the cylinder of the steam-engine, in which the piston moves up and down; to imitate which, wrap a little tow about the end of a piece of stick, grease it with tallow, and fit it moderately tight into the tube; when the water is made to boil, the stick will be raised, and when the end is dipped into cold water, the stick will fall as the piston rises and falls in the cylinder.

TO BOIL WATER BY STEAM.

Nearly fill a retort with water, and boil it over a lamp; then immerse the beak into a tumbler of cold water, and the disengaged steam will raise the water to the boiling temperature, though it be at a distance from the source of heat.

DISTILLATION IN MINIATURE.

Fill a kettle with water, and set it on the fire; fix a long metal tube to the spout, and as soon as the water boils, the steam will pass into the tube, and being condensed into water, will drip at the other end of the tube, which corresponds with the worm in the still; it soon, however, becomes as hot as the water, and then the condensation will cease: but, were the tube passed through cold water, as is the worm of the still in a tub, the whole water in the kettle might be boiled away, but reproduced in the tube, and collected from it without the loss of a drop. This simple process resembles distillation, and the kettle and tube the still.

CANDLE OR FIRE CRACKERS.

Provide a number of little glass bulbs, put into each a drop of water, and seal it up; if it be then put into the flame of a candle, or the fire, the heat will soon convert the water into steam, and cause the bulb to burst with a loud report.

STEAM FROM THE KETTLE.

Observe attentively the steam that escapes from the spout of a tea-kettle, at the moment the water begins to boil, and you will perceive the steam to be condensed in minute drops on the interior edges of the spout. A few moments afterwards, provided the water continue to boil, the spout of the kettle will become perfectly dry; and, at the same time, close to it, there will be a certain space, say from one-half to three-fourths of an inch, throughout which not a particle of steam will be perceptible. This may be easily explained. When the water in the kettle begins to boil, the spout being cooler than the steam issuing from it, a portion of that steam is condensed. As more steam escapes, the metal soon becomes as hot as the steam, will no longer condense it, and the spout becomes dry. By this time the steam will displace the air immediately opposite the orifice of the spout, whence it will issue dry and invisible. As it is cooled by mixing with the surrounding air, it assumes its well-known cloudy appearance.

FIRE, WATER, AND AIR.

COLOURED FLAMES.

A VARIETY of rays of light is exhibited by coloured flames, which are not to be seen in white light. Thus, pure hydrogen gas will burn with a blue flame, in which many of the rays of light are wanting. The flame of an oil-lamp contains most of the rays which are wanting in sunlight. Alcohol, mixed with water, when heated or burned, affords a flame with no other rays but yellow. The following salts, if finely powdered, and introduced into the exterior flame of a candle, or into the wick of a spirit-lamp will communicate to flame their peculiar colours:

Muriate of Soda (common salt) Yellow.
Muriate of Potash Pale violet.
Muriate of Lime Brick red.
Muriate of Strontia Bright crimson.
Muriate of Lithia Red.
Muriate of Baryta Pale _apple_-green.
Muriate of Copper Bluish green.
Borax Green.

Or, either of the above salts may be mixed with spirit of wine, as directed for Red Fire.

YELLOW FLAME.

Burn spirits of wine on common table salt or saltpetre.

ORANGE-COLOURED FLAME.

Burn spirit of wine on chloride of calcium, a substance obtained by evaporating muriate of lime to dryness.

EMERALD GREEN FLAME.

Burn spirit of wine on a little powdered nitrate of copper.

INSTANTANEOUS FLAME.

Heat together potassium and sulphur, and they will instantly burn very vividly.

Heat a little nitre in a fire-shovel, sprinkle on it flour of sulphur, and it will instantly burn. If iron filings be thrown upon red-hot nitre, they will detonate and burn.

Pound, separately, equal parts of chlorate of potash and lump sugar; mix them, and put upon a plate a small quantity; dip a thread into sulphuric acid, touch the powder with it, and it will burst into a brilliant flame.

Or, put a few grains of chlorate of potash into a table-spoonful of spirit of wine; add one or two drops of sulphuric acid, and the whole will burst into a beautiful flame.

THE CUP OF FLAME.

Put a little newly calcined magnesia into a tea-cup upon the hearth or hob, and suddenly pour in as much concentrated sulphuric acid as will cover the magnesia; in an instant, sparks will be thrown out, and the mixture will become completely ignited. To prevent accidents, the phial containing the sulphuric acid should be tied to the end of a long stick.

TO COOL FLAME BY METAL.

Encircle the very small flame of a lamp with a cold iron wire, which will instantly cause its extinction.

PROOF THAT FLAME IS HOLLOW.

Pour some spirit of wine into a watch-glass, and inflame it; place a straw across this flame, and it will only be ignited and charred at the outer edge; the middle of the straw will be uninjured, for there is no ignited matter in the centre of the flame.

Or, introduce into the middle of the flame one end of a glass tube, when the vapour will rise through it, and may be lighted at the other end of the tube.

CAMPHOR SUBLIMED BY FLAME.

Set a metallic plate over the flame of a spirit-lamp; place upon it a small portion of camphor under a glass funnel; and the camphor will be beautifully sublimed by the heat of the lamp, in an efflorescent crust on the sides of the funnel.

GREEN FIRE.

A beautiful green fire may be thus made. Take of flour of sulphur, thirteen parts; nitrate of baryta, seventy-seven; oxymuriate of potassa, five; metallic arsenic, two; and charcoal, three. Let the nitrate of baryta be well dried and powdered; then add to it the other ingredients, all finely pulverized, and exceedingly well mixed and rubbed together. Place a portion of the composition in a small tin pan, having a polished reflector fitted to one side, and set light to it; when a splendid green illumination will be the result. By adding a little calamine, it will burn more slowly.

BRILLIANT RED FIRE.

Weigh five ounces of dry nitrate of strontia, one ounce and a half of finely-powdered sulphur, five drams of chlorate of potash, and four drams of sulphuret of antimony. Powder the chlorate of potash and the sulphuret of antimony separately in a mortar, and mix them on paper; after which, add them to the other ingredients, previously powdered and mixed. No other kind of mixture than rubbing together on paper is required. For use, mix with a portion of the powder a small quantity of spirit of wine, in a tin pan resembling a cheese-toaster, light the mixture, and it will shed a rich crimson hue: when the fire burns dim and badly, a very small quantity of finely-powdered charcoal or lamp-black will revive it.

PURPLE FIRE.

Dissolve chloride of lithium in spirit of wine; and when lighted, it will burn with a purplish flame.

SILVER FIRE.

Place upon a piece of burning charcoal a morsel of the dried crystals of nitrate of silver, (not the lunar caustic,) and it will immediately throw out the most beautiful sparks that can be imagined, whilst the surface of the charcoal will be coated with silver.

THE FIERY MOUNTAIN.

Put into a glass tumbler fifteen grains of finely granulated zinc, and six grains of phosphorus cut into very small pieces, beneath water. Mix in another glass, gradually, a dram of sulphuric acid with two drams of water. Remove both glasses into a dark room, and there pour the diluted acid over the zinc and phosphorus in the glass: in a short time, beautiful jets of bluish flame will dart from all parts of the surface of the mixture; it will become quite luminous, and beautiful luminous smoke will rise in a column from the glass; thus representing a fountain of fire.

THE ARTIFICIAL CONFLAGRATION.

Put into a small, narrow-necked earthen bottle, half an ounce of muriate of ammonia, an ounce of camphor, and two ounces of highly rectified spirit of wine; set fire to it, and the room will seem to be in flames. This experiment should be performed in the dark.

INFLAMMABLE POWDER.

Heat a small portion of the grey powder of aluminum, and it will ignite, inflame, and burn with great rapidity. Or, blow a little of this powder into the flame of a candle, and it will produce a small shower of sparks, brilliant as those from iron filings.

COMBUSTION WITHOUT FLAME.

Light a small _green_ wax-taper; in a minute or two, blow out the flame, and the wick will continue red-hot for many hours; and, if the taper were regularly and carefully uncoiled, and the room kept free from currents of air, the wick would burn on in this manner until the whole taper were consumed. The same effect is not produced when the colour of the wax is red, on which account, red wax-tapers are safer than green; for the latter, if left imperfectly extinguished, may set fire to any object with which they are in contact.

COMBUSTION OF THREE METALS.

Mix a grain or two of potassium with an equal quantity of sodium; add a globule of quicksilver, and the three metals, when shaken, will take fire, and burn vividly.

TO MAKE PAPER INCOMBUSTIBLE.

Take a smooth cylindrical piece of metal, about one inch and a half in diameter, and eight inches long; wrap very closely round it a piece of clean writing paper, then hold the paper in the flame of a spirit-lamp, and it will not take fire; but it may be held there for a considerable time, without being in the least affected by the flame.

SINGULAR EXPERIMENTS WITH GLASS TUBES.

A most remarkable phenomenon is produced in glass tubes, under certain circumstances. When these are laid before a fire in a horizontal position, having their extremities properly supported, they acquire a rotatory motion round their axis, and also a progressive motion towards the fire, even when their supports are declining from the fire, so that the tubes will move a little way upwards to the fire. When the progressive motion of the tubes towards the fire is stopped by any obstacle, their rotation still continues. When the tubes are placed in a nearly upright posture, leaning to the right hand, the motion will be from east to west; but if they lean to the left hand, the motion will be from west to east; and the nearer they are placed to the upright posture, the less will the motion be either way. If the tube be placed horizontally on a glass plane, the fragment, for instance, of coach window glass, instead of moving towards the fire, it will move from it, and about its axis in a contrary direction to what it had done before; nay, it will recede from the fire, and move a little upwards, when the plane inclines towards the fire. These experiments succeed best with tubes about twenty or twenty-two inches long, which have in each end a pretty strong pin fixed in cork for their axis.

AQUATIC BOMB.

Drop about two grains of potassium into a saucer of cold water. It will instantly burst into flame, with a slight explosion, burn vividly on the surface, and dart about with great violence in the form of a red-hot fire ball.

HEAT NOT TO BE ESTIMATED BY TOUCH.

Hold both hands in water which causes the thermometer to rise to ninety degrees, and when the liquid has become still, you will be insensible of the heat, and that the hand is touching any thing. Then remove one hand to water that causes the thermometer to rise to 200 degrees, and the other in water at thirty-two degrees. After holding the hands thus for some time, remove them, and again immerse them in the water at ninety degrees; when you will feel _warmth_ in one hand and _cold_ in the other. To the hand which had been immersed in the water at thirty-two degrees, the water at ninety degrees will feel hot; and to the hand which had been immersed in the water at 200 degrees, the water at ninety degrees will feel cold. If, therefore, the touch in this case be trusted, the same water will be judged to be hot and cold at the _same_ time.

FLAME UPON WATER.

Fill a wine-glass with cold water, pour lightly upon its surface a little ether; light it by a slip of paper, and it will burn for some time.

ROSE-COLOURED FLAME ON WATER.

Drop a globule of potassium, about the size of a large pea, into a small cup nearly full of water, containing a drop or two of strong nitric acid; the moment that the metal touches the liquid, it will float upon its surface, enveloped with a beautiful rose-coloured flame, and entirely dissolve.

TO SET A MIXTURE ON FIRE WITH WATER.

Pour into a saucer a little sulphuric acid, and place upon it a chip of sodium, which will float and remain uninflamed; but the addition of a drop of water will set it on fire.

WAVES OF FIRE ON WATER.

On a lump of refined sugar let fall a few drops of phosphuretted ether, and put the sugar into a glass of warm water, which will instantly appear on fire at the surface, and in waves, if gently blown with the breath. This experiment should be exhibited in the dark.

EXPLOSION IN WATER.

Throw very small pieces of phosphuret of potassium into a basin of water, and they will produce separate explosions. The same substance will also burn with great brilliancy, when exposed to air.

WATER FROM THE FLAME OF A CANDLE.

Hold a cold and dry bell-glass over a lighted candle, and watery vapour will be directly condensed on the cold surface; then close the mouth of the glass with a card or plate, and turn the mouth uppermost; remove the card, quickly pour in a little lime-water, a perfectly clear liquid, and it will instantly become turbid and milky, upon meeting with the contents of the glass, just as lime-water changes when dropped into a glass of water.

FORMATION OF WATER BY FIRE.

Put into a tea-cup a little spirit of wine, set it on fire, and invert a large bell-glass over it. In a short time, a thick watery vapour will be seen upon the inside of the bell, which may be collected by a dry sponge.

BOILING UPON COLD WATER.

Provide a tall glass jar, filled with cold water, and place in it an air thermometer, which will nearly reach the surface; upon the surface place a small copper basin, into which put a little live charcoal: the surface of the water will soon be made to boil, while the thermometer will show that the water beneath is scarcely warmer than it was at first.

CURRENTS IN BOILING WATER.

Fill a large glass tube with water, and throw into it a few particles of bruised amber; then hold the tube, by a handle for the purpose, upright in the flame of a lamp, and, as the water becomes warm, it will be seen that currents, carrying with them the pieces of amber, will begin to ascend in the centre, and to descend towards the circumference of the tube. These currents will soon become rapid in their motions, and continue till the water boils.

HOT WATER LIGHTER THAN COLD.

Pour into a glass tube, about ten inches long, and one inch in diameter, a little water coloured with pink or other dye; then fill it up gradually and carefully with colourless water, so as not to mix them: apply heat at the bottom of the tube, and the coloured water will ascend and be diffused throughout the whole.

The circulation of warm water may be very pleasingly shown, by heating water in a tube similar to the foregoing; the water having diffused in it some particles of amber, or other light substance not soluble in water.

EXPANSION OF WATER BY COLD.

All fluids, except water, diminish in bulk till they freeze. Thus, fill a large thermometer tube with water, say of the temperature of eighty degrees, and then plunge the bulb into pounded ice and salt, or any other freezing mixture: the water will go on shrinking in the tube till it has attained the temperature of about forty degrees; and then, instead of continuing to contract till it freezes, (as is the case with all other liquids,) it will be seen slowly to expand and consequently to rise in the tube until it congeals. In this case, the expansion below forty degrees, and above forty degrees, seems to be equal: so that the water will be of the same bulk at thirty-two degrees as at forty-eight degrees, that is, at eight degrees above or below forty degrees.

THE CUP OF TANTALUS.