Part 7
Take a square bottle of thin glass, and of any size. Apply it to the hole of the air-pump, and exhaust the air. The bottle will sustain the weight of the external air as long as it is able, but at length it will suddenly burst into very small particles, and with a loud explosion.
An opposite effect will be produced, if the mouth of a bottle be sealed so close that no air can escape; then place it in the receiver, and exhaust the air from its surface. The air which is confined within the bottle, when the external air is drawn off, will act so powerfully as to break the bottle into pieces.
_Glass broken by Air._
Lay a square of glass on the top of an open receiver, and exhaust the air. The weight of the external air will press on the glass, and smash it to atoms.
_The Hand fixed by Air._
If a person hold his hand on an open receiver, and the air be exhausted, it will be fixed as if pressed by a weight of sixty pounds.
_Water boiled by Air._
Take water made so warm that you can just bear your hand in it, but that has not been boiled; put it under the receiver, and exhaust the air. Bubbles of air will soon be seen to rise, at first very small, but presently become larger, and will be at last so great, and rise with such rapidity, as to give the water the appearance of boiling. This will continue till the air is let into the receiver, when it will instantly cease.
_Aërial Bubbles._
Take a stone, or any heavy substance, and putting it in a large glass with water, place it in the receiver. The air being exhausted, the spring of that which is in the pores of the solid body, by expanding the particles, will make them rise on its surface in numberless globules, which resemble the pearly drops of dew on the tops of the grass. The effect ceases when the air is let into the receiver.
_The floating Stone._
To a piece of cork tie a small stone that will just sink it; and, putting it in a vessel of water, place it under the receiver. Then exhausting the receiver, the bubbles of air will expand from its pores, and, adhering to its surface, will render it, together with the stone, lighter than water, and consequently they will rise to the surface, and float.
_Withered Fruit restored._
Take a shrivelled apple, and, placing it under the receiver, exhaust the air. The apple will immediately be plumped up, and look as fresh as when first gathered: for this reason, that the pressure of the external air being taken off, the air in the apple extends it, so much indeed that it will sometimes burst. If the air be let into the receiver, the apple will be restored to its pristine shrivelled state.
_Vegetable Air-Bubbles._
Put a small branch of the tree with its leaves, or part of a small plant, in a vessel of water, and, placing the vessel in the receiver, exhaust the air.
When the pressure of the external air is taken off, the spring of that contained in the air-vessels of the plant, by expanding the particles, will make them rise from the orifices of all the vessels for a long time together, and produce a most beautiful appearance.
_The Mercurial Wand._
Take a piece of stick, cut it even at each end with a penknife, and immerse it in a vessel of mercury. When the air is pumped out of the receiver, it will at the same time come out of the pores of the wood, through the mercury, as will be visible at each end of the stick. When the air is again let into the receiver, it falls on the surface of the mercury, and forces it into the pores of the wood, to possess the place of the air.
When the rod is taken out, it will be found considerably heavier than before, and that it has changed its colour, being now all over of a bluish hue. If cut transversely, the quicksilver will be seen to glitter in every part of it.
_The Magic Bell._
Fix a small bell to the wire that goes through the top of the receiver. If you shake the wire, the bell will ring while the air is in the receiver; but when the air is drawn off, the sound will by degrees become faint, till at last not the least noise can be heard. As you let the air in again, the sound returns.
_Feathers heavier than Lead._
At one end of a fine balance, hang a piece of lead, and at the other as many feathers as will poise it; then place the balance in the receiver. As the air is exhausted, the feathers will appear to overweigh the lead, and when all the air is drawn off, the feathers will preponderate, and the lead ascend.
_The self-moving Wheel._
Take a circle of tin, about ten inches in diameter, or of any other size that will go into the receiver, and to its circumference fix a number of tin vanes, each about an inch square. Let this wheel be placed between two upright pieces on an axis, whose extremities are quite small, so that the wheel may turn in a vertical position with the least possible force. Place the wheel and axis in the receiver, and exhaust the air. Let there be a small pipe with a cock; one end of the pipe to be outside the top of the receiver, and the other to come directly over the vanes of the wheel.
When the air is exhausted, turn the cock, and a current will rush against the vanes of the wheel, and set it in motion, which will increase, till the receiver is filled with air.
_The Artificial Halo._
Place a candle on one side of the receiver, and let the spectator place himself at a distance from the other side. Directly the air begins to be exhausted, the light of the candle will be refracted in circles of various colours.
_The Mercurial Shower._
Cement a piece of wood into the lower part of the neck of an open receiver, and pour mercury over it. After a few strokes of the pump, the pressure of the air on the mercury will force it through the pores of the wood in the form of a beautiful shower. If you take care that the receiver is clear and free from spots or dust, and it is dry weather, it will appear like a fiery shower, when exhibited in a dark room.
_Magic Fountain._
Take a tall glass tube, hermetically sealed both at top and bottom, by means of a brass cap screwed on to a stop-cock, and place it on the plate of the pump. When the air is exhausted, turn the cock, take the tube off the plate, and plunge it into a basin of mercury or water. Then the cock being again turned, the fluid, by the pressure of the air, will play upon the tube in the form of a beautiful fountain.
_The Exploded Bladder._
Take a glass pipe open at both ends, to one of which tie fast a wet bladder, and let it dry. Then place it on the plate of the pump. While the air presses the bladder equally on both sides, it will lie even and straight; but as soon as the air is exhausted, it will press inwards, and be quite concave on the upper side. In proportion as the air is exhausted, the bladder will become more stretched; it will soon yield to the incumbent pressure, and burst with a loud explosion. To make this experiment more easy, one part of the bladder should be scraped with a knife, and some of its external fibres taken off.
_The Cemented Bladder._
Tie the neck of the bladder to a stop-cock, which is to be screwed to the plate of the pump, and the air exhausted from the bladder; then turn the stop-cock, to prevent the re-entrance of the air, and unscrew the whole from the pump. The bladder will be transformed into two flat skins, so closely applied together, that the strongest man cannot raise them half an inch from each other; for an ordinary-sized bladder, of six inches across the widest part, will have one side pressed upon the other with a force equal to 396 pounds' weight.
_Cork heavier than Lead._
Let a large piece of cork be pendent from one end of a balance beam, and a small piece of lead from the other; the lead should rather preponderate. If this apparatus be placed under a receiver on the pump, you will find that when the air is exhausted, the lead, which seemed the heaviest body, will ascend, and the cork outweigh the lead. Restore the air, and the effect will cease. This phenomenon is only on account of the difference of the size in the two objects. The lead, which owes its heaviness to the operation of the air, yields to a lighter because a larger substance when deprived of its assistance.
_The animated Bacchus._
Construct a figure of Bacchus, seated on a cask; let his belly be formed by a bladder, and let a tube proceed from his mouth to the cask. Fill this tube with coloured water or wine, then place the whole under the receiver. Exhaust the air, and the liquor will be thrown up into his mouth. While he is drinking, his belly will expand.
_The Artificial Balloon._
Take a bladder containing only a small quantity of air, and a piece of lead to it, sufficient to sink it, if immersed in water. Put this apparatus into a jar of water, and place the whole under a receiver. Then exhaust the air, and the bladder will expand, become a balloon lighter than the fluid in which it floats, and ascend, carrying the weight with it.
_Curious Experiments with a Viper._
Many natural philosophers, in their eagerness to display the powers of science, have overlooked one of the first duties of life, humanity; and, with this view, have tortured and killed many harmless animals, to exemplify the amazing effects of the air-pump. We, however, will not stain the pages of this little work by recommending any such species of cruelty, which in many instances can merely gratify curiosity; but as our readers might like to read the effect on animals, we extract from the learned Boyle an account of his experiment with a viper.
He took a newly-caught viper, and, shutting it up in a small receiver, extracted the air. At first, upon the air being drawn away, the viper began to swell; a short time after it gasped and opened its jaws; it then resumed its former lankness, and began to move up and down within the receiver, as if to seek for air. After a while, it foamed a little, leaving the foam sticking to the inside of the glass; soon after, the body and neck became prodigiously swelled, and a blister appeared on its back. Within an hour and a half from the time the receiver was exhausted, the distended viper moved, being yet alive, though its jaws remained quite stretched; its black tongue reached beyond the mouth, which had also become black in the inside: in this situation it continued for three hours; but on the air being re-admitted, the viper's mouth was presently closed, and soon after opened again; and these motions continued some time, as if there were still some remains of life.
It is thus with animals of every kind; even minute microscopical insects cannot live without air.
_Experiments with Sparrows._
Count Morozzo placed successively several full-grown sparrows under a glass receiver, inverted over water. It was filled with atmospheric air, and afterwards with vital air. He found,
First.--That in _atmospheric_ air, HOURS MIN. The first sparrow lived 3 0 The second sparrow lived 0 3 The third sparrow lived 0 1
The water rose in the vessels eight lines during the life of the first; four during the life of the second; and the third produced no absorption.
Second.--In _vital_ air or _oxygen_, HOURS MIN. The first sparrow lived 5 23 The second 2 10 The third 1 30 The fourth 1 10 The fifth 0 30 The sixth 0 47 The seventh 0 27 The eighth 0 30 The ninth 0 22 The tenth 0 21
The above experiments elicit the following conclusions:--1. That an animal will live longer in vital than in atmospheric air.--2. That one animal can live in air, in which another has died.--3. That, independently of air, some respect must be had to the constitution of the animal; for the sixth lived 47 minutes, the fifth only thirty.--4. That there is either an absorption of air, or the production of a new kind of air, which is absorbed by the water as it rises.
AMUSING EXPERIMENTS IN ELECTRICITY.
_The Animated Feather._
Electrify a smooth glass tube with a rubber, and hold a small feather at a short distance from it. The feather will instantly fly to the tube, and adhere to it for a short time; it will then fly off, and the tube can never be brought close to the feather till it has touched the side of the room, or some other body that communicates with the ground. If, therefore, you take care to keep the tube between the feather and the side of the room, you may drive it round to all parts of the room without touching it; and, what is very remarkable, the same side of the feather will be constantly opposite the tube.
While the feather is flying before the smooth tube, it will be immediately attracted by an excited rough tube or a stick of wax, and fly continually from one tube to the other, till the electricity of both is discharged.
_The Candle lighted by Electricity._
Charge a small coated phial, whose knob is bent outwards so as to hang a little over the body of the phial; then wrap some loose cotton over the extremity of a long brass pin or wire, so as to stick moderately fast to its substance. Next roll this extremity of the pin, which is wrapped up in cotton, in some fine powdered resin; then apply the extremity of the pin or wire to the external coating of the charged phial, and bring, as quickly as possible, the other extremity, that is wrapped round with cotton, to the knob; the powdered resin takes fire, and communicates its flame to the cotton, and both together burn long enough to light a candle. Dipping the cotton in oil of turpentine will do as well, if you use a larger sized jar.
_Candle Bombs._
Procure some small glass bubbles, having a neck about an inch long, with very slender bores, by means of which a small quantity of water is to be introduced into them, and the orifice afterwards closed up. This stalk being put through the wick of a burning candle, the flame boils the water into a steam, and the glass is broken with a loud explosion.
_The Artificial Spider._
Cut a piece of burnt cork, about the size of a pea, into the shape of a spider; make its legs of linen thread, and put a grain or two of lead in it to give it more weight. Suspend it by a fine line of silk between an electrified arch and an excited stick of wax; and it will jump continually from one body to the other, moving its legs at the same time, as if animated, to the great surprise of the unconscious spectator.
_The Miraculous Portrait._
Get a large print (suppose of the king) with a frame and glass. Cut the print out at about two inches from the frame all round; then with thin paste fix the border that is left on the inside of the glass, pressing it smooth and close; fill up the vacancy, by covering the glass well with leaf-gold or thin tin-foil, so that it may lie close. Cover likewise the inner edge of the bottom part of the back of the frame with the same tin-foil, and make a communication between that and the tin-foil in the middle of the glass; then put in the board, and that side is finished. Next turn up the glass, and cover the fore-side with tin-foil, exactly over that on the back part; and when it is dry, paste over it the panel of the print that was cut out, observing to bring the corresponding parts of the border and panel together, so that the picture will appear as at first, only part of it behind the glass, and part before. Lastly, hold the print horizontally by the top, and place a little moveable gilt crown on the king's head.
Now, if the tin-foil on both sides of the glass be moderately electrified, and another person take hold of the bottom of the frame with one hand, so that his fingers touch the tin-foil, and with the other hand attempt to take off the crown, he will receive a very smart blow, and fail in the attempt. The operator, who holds the frame by the upper end, where there is no tin-foil, feels nothing of the shock, and can touch the face of the king without danger, which he pretends is a test of his loyalty.
_The Cup of Tantalus._
You place a cup of any sort of metal on a stool of baked wood or a cake of wax. Fill it to the brim with any liquor; let it communicate with the branch by a small chain; and when it is moderately electrified, desire a person to taste the liquor, without touching the cup with his hands, and he will instantly receive a shock on his lips. The motion of the wheel being stopped, you taste the liquor yourself, and desire the rest of the company to do so; you then give your operator (who is concealed in an adjoining room) the signal, and he again charges the cup; you desire the same person to taste the liquor a second time, and he will receive a second shock.
_Magical Explosion._
Make up some gunpowder, in the form of a small cartridge, in each end of which put a blunt wire, so that the ends inside of the cartridge be about half an inch off each other; then join the chain that proceeds from one side of the electrifying battery, to the wire at the other end, the shock will instantly pass through the powder, and set it on fire.
_Artificial Earthquake._
In the middle of a large basin of water, lay a round wet board. On the board place any kind of building, made of pasteboard, of separate pieces, and not fastened together. Then, fixing a wire that communicates with the two chains of the electrifying battery, so that it may pass over the board and the surface of the water, upon making the explosion, the water will become agitated as in an earthquake, and the board, moving up and down, will overturn the structure, while the cause of the commotion is totally concealed.
_The Magic Dance._
From the middle of the brass arch suspend three small bells. The two outer bells hang by chains, and the middle one by a silk string, while a chain connects it with the floor. Two small knobs of brass, which serve as clappers, hang by silk strings, one between each two bells. Therefore, when the two outer bells communicating with the conductor are electrified, they will attract the clappers and be struck by them. The clappers being thus loaded with electricity, will be repelled, and fly to discharge themselves upon the middle bell, after which they will be again attracted by the outer bells; and thus, by striking the bells alternately, the ringing may be continued as long as the operator pleases.
You next suspend a plate of metal from the same part of the arch to which the bells are connected; then, at the distance of a few inches from the arch, and exactly under it, place a metal stand _of the same size_. On the stand place several figures of men, animals, or what you please, cut in paper, and pretty sharply pointed at each extremity. When the plate that hangs from the arch is electrified, the figures will dance with astonishing rapidity, and the bells will keep ringing, to the no small entertainment of the spectators.
_The Electrical Fountain._
Suspend a vessel of water from the middle of the brass arch, and place in the vessel a small tube. The water will be one continued stream; and if the electrification be strong, a number of streams will issue, in form of a cone, the top of which will be at the extremity of the tube. This experiment may be stopped and renewed almost instantly, as if at the word of command.
_The Electric Kite._
Make a small cross of two light strips of cedar, the arms so long as to reach to the four corners of a large thin silk handkerchief, when extended; tie the corners of the handkerchief to the extremities of the cross; and you have the body of the kite, which being properly accommodated with a tail, loop, and string, will rise in the air like those made of paper; but this being silk, it is more adapted to bear the wet and wind of a thunder gust, without tearing. To the top of the upright stick of the cross is to be fixed a very sharp-pointed wire, rising a foot or more above the wood. To the end of the twine is to be tied a silk ribbon, and where the silk and twine join, a key may be fastened. This kite is to be raised when a thunder-storm appears to be coming on; and the person who holds the string must stand within a door or window, or under some cover, so that the silk ribbon may not be wet; and care must be taken that the twine do not touch the frame of the door or window. As soon as any of the thunder clouds come over the kite, the pointed wire will draw the electric fire from them, and the kite, with all the twine, will be electrified, while the loose filaments of the twine will stand out every way, and be attracted by an approaching finger. When the rain has wetted the kite and twine, so that it can conduct the electric fire freely, you will find it stream out plentifully from the key, on the approach of your knuckle. At this key an electric phial may be charged; and from electric fire thus obtained, spirits may be kindled, and all the other electric experiments performed which are usually done by the help of a rubbed glass or tube; and thereby the identity of the electric matter with that of lightning completely demonstrated.
_The Magic Chase._
On the top of a finely-pointed wire, rising perpendicularly from the conductor, let another wire, sharpened at each end, be made to move freely, as on a centre. If it be well balanced, and the points bent horizontally, in opposite directions, it will, when electrified, turn very swiftly round, by the re-action of the air against the current which flows from off the points. These points may be nearly concealed, and the figures of men and horses, with hounds, and a hare, stag, or fox, may be placed upon the wires, so as to turn round with them, when they appear as if in pursuit. The chase may be diversified, and a greater variety of figures upon them, by increasing the number of wires proceeding from the same centre.
_The Unconscious Incendiary._
Let a person stand upon a stool made of baked wood, or upon a cake of wax, and hold a chain which communicates with the branch. On turning the wheel he will become electrified; his whole body forming part of the prime conductor; and he will emit sparks whenever he is touched by a person standing on the floor.
If the electrified person put his finger, or a rod of iron, into a dish containing warm spirits of wine, it will be immediately in a blaze; and if there be a wick or thread in the spirit, that communicates with a train of gunpowder, he may be made to blow up a magazine, or set a city on fire, with a piece of cold iron, and at the same time be ignorant of the mischief he is doing.
_The Inconceivable Shock._
Put in a person's hand a wire that is fixed on to the hook that comes from the chain, which communicates with one side of the battery, and in his other hand put a small wire with a hook at the end of it, which you direct him to fix on to a hook which comes from the other chain. On attempting to do this, he will instantly receive a shock from his body, without being able to guess the cause.
Care should be taken that the shock be not too strong; and regard should be had to the constitution and disposition of the party, as a shock that would hardly affect one person, might be productive of very serious consequences to another.
Much entertainment may be derived from concealing the chain that communicates with that which proceeds from the outside of the battery, under a carpet, and placing the wire that communicates with the chain from the inside, in such a manner that a person may put his hand on it without suspicion, at the same time that his feet are upon the other wire.