After some time a strong pressure will be exercised on the liquid, and the water rising rapidly up through the vertical tube, will spout out as from a fountain.
This experiment may be varied and reduced to a simpler one. Take one jar, fill it up two-thirds with water, and fit it with a cork with two holes, through which pass two tubes; the one going to the bottom, the other resting just over the surface of the liquid. The latter should be fitted with a receiver.
Seal the cork so as to render it air-tight. In the top receiver pour water, which will go down into the jar and raise the level of the water already contained in it.
The air, being compressed, will act upon the liquid mass in the lower jar, and the water will escape through the free tube in a jet with more or less force according to the pressure exercised.
Do not be cast down because you see another term to be explained. A gas is, you may have already guessed, simply a fluid. Matter exists in three states, solid, liquid and gaseous. Everything can exist in these three states under different conditions of heat and pressure.
For instance, ice, water, and steam are precisely the same thing, a mixture of oxygen and hydrogen, though in different states. Hence steam is simply the gaseous form of ice or water. Now some gases are heavier than air, and among them is carbonic acid, a gas given off from the lungs in breathing.
By means of a very simply-constructed balance, you can prove this gas to be heavier than air. Sounds queer, doesn’t it? to talk of weighing something that you cannot handle or see.
It is not difficult to do. Bend some wire, minding that the beams of the balance are curved as in the figure.
For one side of the scales a strong cardboard box will answer admirably; for the other the lid of a round box will serve. Hang the whole on a string and adjust it by putting some grains of sand in the round scale on which the weights are placed, to make each side balance one another and the scales are ready for use.
The production of carbonic acid is easy. Pour a little sulphuric acid and water over some chalk. Collect the gas given off in a bottle or jar. In doing so you need not be afraid that it will escape, since it is heavier than the air.
In pouring it in the box of the scale, you will see the box sink down, which is clearly an indication that the gas, which has just been poured into the scale is heavier than the air, whose place it has taken. This experiment may be tried in other curious ways.
With some lycopodium, powder the surface of a large or small vessel of water; you may then challenge any one to drop a piece of money into the water, and that you will get it with the hand without wetting your skin. The lycopodium adheres to the hand, and prevents its contact with the water. A little shake of the hand after the feat is over will dislodge the powder.
This is another experiment on the density of liquids. In a small jar put some wine or colored alcohol, and close it with a cork, through which you have passed a small tube, a quill or a hollow straw. In lowering this jar gently in a pail full of water, you will soon see the liquid escape and rise to the surface of the water, describing spirals which resemble smoke, and give a pretty good image, considerably diminished, of a volcano.
Make two holes in the wainscot of a room, each a foot high and ten inches wide, and about a foot distant from each other. Let these apertures be about the height of a man’s head, and in each of them place a transparent glass in a frame like a common mirror.
Behind the partition, and directly facing each aperture, place two mirrors inclosed in the wainscot, in an angle of forty-five degrees. These mirrors are each to be eighteen inches square, and all the space between must be inclosed with pasteboard painted black, and well closed that no light can enter; let there be also two curtains to cover them, which you may draw aside at pleasure.
When a person looks into one of these fictitious mirrors, instead of seeing his own face, he will see the object that is in front of the other; thus, if two persons stand at the same time before these mirrors, instead of each seeing himself, they will reciprocally see each other.
There should be a sconce with a lighted candle placed on each side of the two glasses in the wainscot, to enlighten the faces of the persons who look in them, or the experiment will not have so remarkable an effect.
To accomplish this metamorphosis, it is necessary to have earthen vases which have little edges or rims near their mouths, and should be of a size sufficiently large to hold suspended the bird or flower which you intend placing in them. You should likewise be provided with stoppers of cork, of a diameter equal to that of their mouths. To make an experiment upon some bird, it is necessary to commence by making a hole in the stopper, sufficiently large to contain the neck of the bird without strangling it. This done, you divide the diameter of the stopper into two equal parts so as to facilitate the placing of it around the neck without doing injury to the bird. The two parts being brought together, you place at the bottom of the vase an ounce of quicklime, and beneath that a quarter of an ounce of sal ammoniac. When you perceive the effervescence commence to take place, you promptly insert the stopper, to which the bird is attached, leaving the neck outside. The plumage of the body, exposed to this effervescent vapor, will become impregnated with the various colors produced by this chemical combination.
Fix three pins in the table and lay the piece of money upon them; then place a heap of the flour of sulphur below the piece of money, and another above it, and set fire to them. When the flame is extinct, you will find on the upper part of the piece a thin plate of metal, which has been detached from it.
Mix two drachms of the filings of iron with one ounce of concentrated spirit of vitriol in a strong bottle that holds about a quarter of a pint; stop it close, and in a few moments shake the bottle; then taking out the cork, put a lighted candle near its mouth which should be a little inclined, and you will soon observe an inflammation arise from the bottle, attended with a loud explosion.
To guard against the danger of the bottle bursting, the best way would be to bury it in the ground and apply the light to the mouth by means of a taper fastened to the end of a long stick.
Ether poured upon a glass tube in a thin stream will evaporate and cool it to such a degree that water contained in it may be frozen.
Fill a quill with quicksilver; seal it at both ends with good hard wax; then have an egg boiled; take a small piece of the shell off the small end and thrust in the quill with the quicksilver; lay it on the ground and it will not cease tumbling about as long as any heat remains in it; or if you put quicksilver into a small bladder and blow it up, then warm the bladder, it will skip about as long as heat remains in it.
Dissolve camphor in spirits of wine and deposit the vessel containing the solution in a very close room, where the spirits of wine must be made to evaporate by strong and speedy boiling. If any one then enters the room with a lighted candle the air will inflame, while the combustion will be so sudden and of so short a duration as to occasion no danger.
Bring a bar of iron to a white heat and then apply to it a roll of sulphur. The iron will immediately melt and run into drops.
The experiment should be performed over a basin of water, in which the drops that fall down will be quenched. These drops will be found reduced into a sort of cast iron.
Take a crystal or two of the nitrate of copper and bruise them; then moisten them with water and roll them up quickly in a piece of tinfoil, and in half a minute or little more, the tinfoil will begin to smoke and soon after take fire and explode with a slight noise. Unless the crystals of the nitrate of copper are moistened, no heat will be produced.
Put three ounces of rock alum and one ounce of honey or sugar into a new earthen dish, glazed, and which is capable of standing a strong heat; keep the mixture over the fire, stirring it continually until it becomes very dry and hard; then remove it from the fire and pound it to a coarse powder. Put this powder into a long-necked bottle, leaving a part of the vessel empty; and having placed it in the crucible, fill up the crucible with fine sand and surround it with burning coals. When the bottle has been kept at a red heat for about seven or eight minutes, and no more vapor issues from it, remove it from the fire, then stop it with a piece of cork; and, having suffered it to cool, preserve the mixture in small bottles, well closed.
If you unclose one of these bottles and let fall a few grains of this powder on a bit of paper, or any other very dry substance it will first become blue, then brown, and will at last burn the paper or other substance on which it has fallen.
A very pleasing exhibition may be made, with very little trouble or expense, in the following manner: Provide a box, which you can fit up with architectural designs cut on pasteboard; prick small holes into those parts of the building where you wish the illuminations to appear, observing that, in proportion to the perspective, the holes are to be made smaller, and on the near objects the holes are to be made larger. Behind these designs thus perforated you fix a lamp or candle, but in such a manner that the reflection of the light shall only shine through the hole: then placing a light of just sufficient brilliancy to show the design of the buildings before it, and making a hole for the sight at the front end of the box, you will have a tolerable representation of illuminated buildings.
The best way of throwing the light in front is to place an oiled paper before it, which will cast a mellow gleam over the scenery, and not diminish the effect of the illumination. This can be very easily planned, both not to obstruct the sight, nor be seen to disadvantage. The lights behind the picture should be very strong, and if a magnifying glass were placed in the sight hole it would tend greatly to increase the effect. The box must be covered in, leaving an aperture for the smoke of the lights to pass through.
The above exhibition can only be shown at candle light; but there is another way, by fixing small pieces of gold on the building, instead of drilling the holes, which gives something like the appearance of illumination, but by no means equal to the foregoing experiment.
N. B.—It would be an improvement if paper of various colors, rendered transparent by oil, were placed between the lights behind the aperture in the buildings, as they would then resemble lamps of different colors.
Put a small quantity of spirits of wine into a glass, and put a cent or coin in with it; then direct the rays of the sun by means of a burning glass upon the coin, and in a short time it will become so hot as to inflame the spirits.
Put half a drachm of solid phosphorus into a large pint flask—holding it slanting that the phosphorus may not break the glass. Pour upon it a gill and a half of water and place the whole over a tea-kettle lamp, or any common tin lamp filled with spirits of wine. Light the wick which should be almost half an inch from the flask; and as soon as the water is heated, streams of fire will issue from the water by starts, resembling sky-rockets; some particles will adhere to the sides of the glass, representing stars, and will frequently display brilliant rays. These appearances will continue at times till the water begins to simmer, when immediately a curious aurora borealis begins, and gradually ascends till it collects to a pointed flame; when it has continued half a minute, blow out the flame of the lamp and the point that was formed will rush down, forming beautiful illuminated clouds of fire, rolling over each other for some time, which, disappearing, a splendid hemisphere of stars presents itself; after waiting a minute or two, light the lamp again, and nearly the same phenomenon will be displayed as from the beginning. Let the repetition of lighting and blowing out the lamp be made for three or four times at least, that the stars may be increased. After the third or fourth time of blowing out the lamp, in a few minutes after the internal surface of the flask is dry, many of the stars will shoot with great splendor from side to side, and some of them will fire off with brilliant rays; these appearances will continue several minutes. What remains in the flask will serve for the same experiment several times, and without adding any more water. Care should be taken after the operation is over, to lay the flask and water in a cool, secure place.
It is an interesting and amusing experiment to inflate a balloon made of gold-beater’s skin (using a little gum arabic to close any holes or fissures), filling it from a bladder or jar, and tying a thread around the mouth of it, to prevent the escape of the gas. When fully blown, attach a fanciful car of colored paper, or very thin pasteboard, to it, and let it float in a large room; it will soon gain the ceiling, where it will remain for any length of time; if it be let off in the open air it will soon ascend out of sight. This experiment may be varied by putting small grains of shot into the car, in order to ascertain the difference between the weight of hydrogen gas and atmospheric air.
Wrap up a very smooth ball of lead in a piece of paper, taking care that there be no wrinkles in it, and that it be everywhere in contact with the ball; if it be held in this state over the flame of a taper, the lead will be melted without the paper being burnt. The lead, indeed, when once fused will not fail in a short time to pierce the paper, and run through.
Infuse a few shavings of logwood in common water, and when the liquid is sufficiently red pour it into a bottle. Then take three drinking glasses and rinse one of them with strong vinegar; throw into the second a small quantity of pounded alum, which will not be observed if the glass has been washed, and leave the third without any preparation. If the red liquor in the bottle be poured into the first glass, it will appear of a straw color; if the second it will pass gradually from a bluish gray to black, when stirred with a key or any piece of iron which has been previously dipped in strong vinegar. In the third glass the red liquor will assume a violet tint.