Should you not have at hand a glass receiver, a wooden reel may serve instead (see fig.). On one of its faces place a piece of strong cardboard, in the middle of which a hook has been fastened; when the rarefaction is made, rather heavy weights must be hooked on before the cardboard is detached from the face of the rest.
Fuse together in a crucible, eight parts of bismuth, five of lead and three of tin; these metals will combine and form an alloy, of which spoons may be made, possessed of the remarkable property of melting in boiled water.
Take a wooden reel and hollow out either the top or bottom, beginning at the hole in the center and working towards the edge. In the hollow place a ball. Apply to the other end the indiarubber tube which conducts the forced air, and the ball will be lifted up (see fig.).
If you are about to perform a conjuring trick, you will, of course take great care that your apparatus is ready. Therefore, clean your piece of iron or steel from dirt. Dip a piece of polished iron—the blade of your knife, for instance—into a solution, either of nitrate or sulphate of copper, when it will assume the appearance of a piece of pure copper.
Before entering into the next series of experiments the young chemist must know that all the substances of which the world and everything in it are made up—i.e., the elements are arranged in two classes, the metals and the non-metals. The former are by far the more numerous, altogether numbering more than fifty. Among the better known are such well known substances as iron, mercury, copper, tin, potassium, antimony, strontium, and nickel. The non-metals are more widely distributed and together made up of the bulk of the universe.
They comprise the gases—oxygen, hydrogen, nitrogen, and chlorine, and such substances as sulphur, carbon, phosphorus and iodine. To the latter class also belongs a peculiar element called fluorine, which, when combined with hydrogen, destroys glass. It is the only liquid known which cannot be contained in a glassen or earthenware vessel, and when used for experimental purposes must be kept in a leaden bottle.
Of course it will be understood that the above is not a complete list by any means, but is sufficient to give a clear idea of the difference between the two classes. The metals generally speaking are of a more or less sparkling, lustrous appearance. The metals, too, are good conductors of heat and electricity, and generally heavy. These characteristics are almost entirely wanting in the non-metals. We shall now give some tricks with the metals.
Potassium was discovered by Sir H. Davy, in the beginning of the present century, while acting upon potash with the enormous galvanic battery of the Royal Institution, consisting of two thousand pairs of four inch plates. It is a brilliant metal, so soft as to be easily cut with a penknife, and so light as to swim upon water, on which it acts with great energy, uniting with the oxygen and liberating the hydrogen, which takes fire as it escapes.
Trace some continuous lines on paper with a camel’s-hair brush dipped in water, and place a piece of potassium about the size of a pea on one of the lines, and it will follow the course of the pencil, taking fire as it runs, and burning with a purplish light.
The paper will be found covered with a solution of ordinary potash. If turmeric paper be used, the course of the potassium will be marked with a deep brown color. Hence if you touch potassium with wet fingers you will burn them.
If a small piece of the metal be placed on a piece of ice, it will instantly take fire, and form a deep hole which will be found to contain a solution of potash.
In consequence of its great affinity for oxygen, potassium must be kept in some fluid destitute of it, such as naphtha acid, which has been displaced by the great affinity or liking of the oxygen and acid for the copper.
2. When the copper is no longer coated, but remains clean and bright when immersed in the fluid, all the silver has been deposited, and the glass now contains a solution of copper.
Nearly all the colors used in the arts are produced by metals and their combinations; indeed, one is named chromium, from a Greek word signifying color, on account of the beautiful tints obtained from its various combinations with oxygen and the other metals. All the various tints, of green, orange, yellow and red are obtained from this metal.
Solutions of most of the metallic salts give precipitates with solutions of alkalies and their salts, as well as with many other substances, such as what are usually called prussiate of potash, hydrosulphret of ammonia, etc. The colors differ according to the metal employed; and so small a quantity is required to produce the color, that the solutions before mixing may be nearly colorless.
To a solution of sulphate of iron add a drop or two of a solution of prussiate of potash, and a blue color will be produced.
2. Substitute sulphate of copper for iron, and the color will be a rich brown.
3. Another blue, of quite a different tint, may be produced by letting a few drops of a solution of ammonia fall into one of sulphate of copper, when a precipitate of a light blue falls down, which is dissolved by an additional quantity of the ammonia, and forms a transparent solution of the most splendid rich blue color.
4. Into a solution of sulphate of iron, drop a few drops of strong infusion of galls, and the color will become a bluish black—in fact ink. A little tea will answer as well as the infusion of galls. This is the reason why certain stuffs formerly in general use for dressing-gowns for gentlemen were so objectionable; for as they were indebted to a salt of iron for their color, buff as it was called, a drop of tea accidentally spilled produced all the effect of a drop of ink.
5. Put into a largish test tube two or three small pieces of granulated zinc, fill it about one-third full of water, put in a few grains of iodine, and boil the water, which will at first acquire a dark purple color, gradually fading as the iodine combines with the zinc. Add a little more iodine from time to time, until the zinc is nearly all dissolved. If a few drops of this solution be added to an equally colorless solution of corrosive sublimate (a salt of mercury), a precipitate will take place of a splendid scarlet color, brighter, if possible, than vermilion, which is also a preparation of mercury.
Some of the metals assume certain definite forms in return from the fluid to the solid state. Bismuth shows this property more readily than most others.
Melt a pound or two of bismuth in an iron ladle over the fire; remove it as soon as the whole is fluid; and when the surface has become solid break a hole in it and pour out the still fluid metal from the interior; what remains will exhibit beautifully formed crystals of a cubic shape.
Sulphur may be crystallized in the same manner, but its fumes, when heated, are so very unpleasant that few would wish to encounter them.
One of the most remarkable facts in chemistry—a science abounding in wonders—is the circumstance that the mere contact of hydrogen, the lightest body known, with the metal platinum, the heaviest when in a state of minute division called spongy platinum, produces an intense heat sufficient to inflame the hydrogen; of course this experiment must be made in the presence of atmospheric air or oxygen. If a small piece of the metal in the state above named be introduced into a mixture of oxygen and hydrogen, it will cause them to explode. A very small quantity of gas should be employed and placed in a jar lightly covered with a card, or the explosion would be dangerous.
Nearly all the metals are characterized by the crystals, which are formed as they pass from a state of intense heat to that of comparative coldness. It is by this process they have been formed when in the mine or vein in the rocks. The earth was once a fiery mass of molten matter, as seen even now when a volcano is in a state of eruption. And it was only by the cooling of the outside shell of the earth, or crust, as it is called, that it became habitable.
When the crust was cooling down the metals crystallized among the cooling rocks and gradually formed the crude arts. You may represent by a very pretty experiment the manner in which this cooling off of the earth took place. Obtain a little flour of sulphur and put it in a red earthenware unglazed jar. Thrust it well into the fire and watch the rust. As soon as the heat has penetrated the vessel the yellow powdery sulphur becomes first of all brown, and then assumes the consistency of thick birdlime. Take out a little of this on the end of a stick and plunge it into cold water. It can then be pulled backwards and forwards like cobblers’ wax. This well represents the state of the half-cooled crust of the earth.
Meanwhile the sulphur on the fire begins to boil, and looks very much like bubbling treacle. Remove it from the fire and allow it to cool. When quite cool the surface will be a flat, yellow mass, like ordinary roll sulphur, which, when ground, give the ordinary flour of sulphur.
With a sharp knife separate the mass from the vessel and look at the under-surface. There it will be found to have assumed a very different form, owing to the exclusion of the air, and consequent slower cooling. Large six-sided crystals, transparent, and of a most exquisitely delicate yellow, will be seen, piled on one another as appear the masses of ore in rocks.
Nature always works in such cases on such a gigantic scale that it seems at first difficult to believe that such huge piles as the Giant’s Causeway in Ireland, or Fingals in Scotland, or the lodes of tin ore in Cornwall, worked by the Phœnicians three thousand years ago, and still being worked, were all formed by the same process.
The time that the earth must have taken to cool fairly staggers the imagination, yet it is only from guessing, by means of such a study as this, that geologists are able to form any idea of how long ago it was that the earth’s crust became cool enough to allow animal and plant life to exist upon it.
The most beautiful crystalline form is perhaps the diamond, and yet this precious gem is but the same thing, chemically, as charcoal. Charcoal is pure carbon in the uncrystallized state, which the magic of crystallization has transformed into the symbol of all that is brilliant and beautiful.
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 turmeric 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 colored alum crystals from breaking or losing their color, 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.
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.
Heat some blue vitriol (sulphate of copper) in an iron ladle till all the water contained in the crystals is driven off, and the color changes to a gray. Take the lumps out without breaking them, and lay the dried blue vitriol on a plate. If this be moistened with water steam is produced; and if a slice of phosphorus is then laid on the sulphate of copper it ignites, demonstrating again that the condensation of a liquid produces heat. The addition of the water restores the blue color, thus proving that water was necessary to the composition of blue vitriol.
Mix five parts by weight of powdered sal ammoniac, five parts of nitre in powder, and sixteen parts of water. A temperature of twenty-two degrees below the freezing point of water is produced; and if a phial of water, or any convenient metallic cylinder containing water, be surrounded with a sufficient quantity of the freezing mixture, ice is formed. The ice clings to the interior of the tube, but may easily be removed by dipping it in tepid water.
This experiment is the reverse of the last and proves that the sudden reduction of a solid to the liquid condition always affords cold.
An amusing combination of two experiments may be made by putting some fresh-burned lime into one tea pot and this freezing mixture into another. When water is poured on the one containing lime, it gives out steam from the spout, while the addition of water to the other produces so much cold that it can hardly be kept in the hand. Thus heat and cold are afforded through the same medium, water.
Melt a small quantity of the sulphate of potash 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 color. Remove the spoon from the flame, when the liquid will become a solid of a brilliant emerald green color, and so remain until 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.
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 gray, 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 vapor of sulphur is very powerfully repelled by heated glass. The flattened form of the particles is owing to the force with which they endeavor 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, to be a satisfactory argument in favor of the repulsive power of heat.
Although glass is a bad conductor it yet allows heat to pass through it, and the purer the glass the more easy is this done. Heat a poker red hot, and having opened a window, apply the poker very near to the outside of the 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. It is well known that if a piece of glass be 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.
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.
Mix a small quantity of chlorate of potash with spirit of wine in a strong saucer; add a little sulphuric acid, and an orange vapor will arise and burst into flame with a loud crackling sound.
Place before a fire a set of polished fire-irons, and beside them a rough, unpolished poker, such as is used in the kitchen, 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.
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.
Dissolve in water a small quantity, about as much as will lay on a ten-cent piece, of chloride of cobalt, which is of a bluish-green color, and the solution will be pink; write with it and the characters will scarcely be visible; but if gently heated they will appear in brilliant green, which will disappear as the paper cools.
Dissolve in water a few grains of prussiate of potash; write with this liquid, which is invisible when dry; wash over with a dilute solution of iron, made by dissolving a nail in a little aqua fortis; a blue and legible writing is immediately apparent.
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 color. A very hot solution will be of a beautiful green color; a cold one a deep purple.
Make a colorless solution of sulphate of copper; add to it a little ammonia equally colorless, and the mixture will be of an intense blue color; add to it a little sulphuric acid, and the blue color will disappear; pour in a little solution of caustic ammonia, and the blue color will be restored. Thus may the liquor be changed at pleasure.
Dissolve indigo in diluted sulphuric acid, and add to it an equal quantity of solution of carbonate of potash. 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 color; add a little lime water and the mixture will be colorless; dip into it a piece of white cloth, dry it rapidly, and in a few hours the cloth will become red.
Mix a little solution of subacetate of lead with port wine; filter the mixture through blotting-paper, and a colorless liquid will pass through; to this add a small quantity of dry salt of tartar; distill in a retort, when a spirit will arise, which may be inflamed.
More than two-thirds of the earth’s surface is water, so that in mere quantity alone it is the most important substance with which we are acquainted. Without it life would be impossible, for, owing to its quality of dissolving other bodies, it may be regarded as the great purifier, as well as the vehicle which brings nourishment to plants and animals alike.
Not only is water useful, but is among the most beautiful of Nature’s products. It has carved the valleys between mountain ranges by its slow dropping for ages, and has made the fairy glens by rushing down their sides in torrents. The stately rivers and the roaring oceans are but forms of its might.
In another state it works out those fantastic grottoes, mountains and fields of glittering white, that make the Polar seas the very head center of dreamland.
In still another form it paints the rainbow in the sky, and hangs like a veil over the landscape, passing from the most delicate blue over the plain to the deep purple clinging to distant hills.
To it the golden and red hues of sunrise and sunset are due. The light fleecy clouds that speak the beauty of spring, and the great thunder stocks that gleam, with lightning flashes are all composed of water, and water alone.
It drives our engines and machinery, and speeds our ships across the sea. Neither is it confined to this earth alone, for astronomers tell us that vast seas and even clouds can be seen on the next great planet to the earth, Mars.
Surely, then, as this wondrous substance is examined, the ancients can be excused for worshiping the ocean as a god, and the old alchemists for believing it to be an element.
Nevertheless, water is not a simple substance. It is composed of two gases, which must be combined before water is produced. These gases are oxygen and hydrogen. Every atom of water consists of one part of the former gas and two parts by volume of the latter. This you may prove in the following way:
Buy a piece of sodium, a metal that must not be touched with the fingers, and thrust it into a small one-ounce jar half full of water; cork the jar tightly.
Through a hole in the cork pass a glass tube, the outer end being drawn in a flame to a fine point. Apply a light at the end of the tube. The escaping gas will catch fire and burn with a light blue flame. This gas is hydrogen.
Next empty the jar and fill with warm water, and place by means of another cork a small glass jar on to the tube. Into the lower jar drop a piece of blazing hot platinum. Repeat this again and again with the same piece of platinum, being careful not to uncork the upper jar, so that every time the metal is dropped into the lower jar, you remove the upper jar with the tube and two corks. After doing this a dozen times or more take a match that is still glowing after having been extinguished, and plunge it into the upper jar. It will burst into flame immediately, and the gas in the upper jar is oxygen.
It has been discovered that a mixture of nitrate of silver with hyposulphite of soda, both of which are remarkably bitter, will produce the sweetest known substance.
Write with French chalk on a looking-glass; wipe it with a handkerchief and the lines will disappear; breathe on it and they will reappear. This alteration will take place for a great number of times, and after the lapse of a considerable period.
Rub together in a mortar a small quantity of sulphate of soda and acetate of lead, and as they mix they will become liquid.
Carbonate of ammonia and sulphate of copper, previously reduced to powder separately, will also, when mixed, become liquid, and acquire a most splendid blue color.
The greater number of salts have a tendency to assume regular forms, or become crystallized, when passing from the fluid to the solid state; and the size and regularity of the crystals depends in a great measure on the slow or rapid escape of the fluid in which they were dissolved.
Sugar is a capital example of this property; the ordinary loaf-sugar being rapidly boiled down, as it is called; while to make rock-candy, which is nothing but sugar in a crystallized form, the solution is allowed to evaporate slowly, and as it cools it forms into those beautiful crystals termed rock-candy. The threads found in the center of some of the crystals are merely placed for the purpose of hastening the formation of the crystals.
Water being a colorous fluid ought, one would imagine when mixed with other substances of no decided color, to produce a colorless 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 color will instantly reappear.
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 color will vanish, but reappear on being dropped into water.
Dissolve chloride of lime in water until it will dissolve no more; measure out an equal quantity of oil of vitriol; both will be transparent fluids; but if equal quantities of each be slowly mixed and stirred together, they will become a solid mass, with the evolution of smoke or fumes.
Rub together in a mortar equal quantities of the crystals of Glauber salts and nitrate of ammonia, and the two salts will slowly become a 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.
Mix four drams of sulphuric acid (oil of vitriol) with one dram of cold water, suddenly, in a cup, and the mixture will be nearly half as hot again as boiling water.
Although this trick is performed by means of chemicals, yet its product is obtained really by the use of mechanical laws. We must remember that ice is exactly the same thing as water so far as its composition is concerned, differing only in its state of density.
Ice, water, and steam differ in density through the possession of a greater or less quantity of heat. Hence, the turning of water into ice really is a case of the operation of mechanical laws.
Now for the experiment. Put into a wide-mouthed jam-jar a smaller glass vessel containing the water to be frozen. Around the latter put a mixture of sulphate of soda (Glauber’s salt) and hydrochloric acid (spirits of salts). The proportions must be eight parts of the former to five of the latter.
The action of these two chemicals on one another is to cause a cold of fifteen to seventeen degrees below zero, or forty-seven degrees below freezing point.
The same result may be obtained by mixing equal parts of nitrate of ammonia and water. In winter-time when the snow is on the ground, with a mixture of one part snow and one part common table salt an intense cold of twenty degrees below zero is obtained.
From this last fact we see how stupid are those people who sprinkle the salt on the pavements to get rid of the snow. True, the latter melts, but only after the production of intense cold, which is the cause of many diseases, not only slight ones like colds and chilblains, but too often the forerunners of consumption and other lung troubles.
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 anything for a second or two. The order of colors will therefore be as follows: green, red, green, black.
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.
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 color will change to yellow, a fact known to gardeners, who by this mode variegate their growing dahlias.
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 color; by adding a little chalk, it will become the color of port wine; and this tint, by the addition of potash may be changed to green or yellow.
Hold a red rose over the blue flame of a common match and the color 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.
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 to a dark room, and they will not change; but expose them to a strong light, and they will be of an indelible black.
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 center 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 it 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 will hang from the acorn in a drop, the skin will burst, and the root will protrude and thrust itself in 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.
A variety of rays of light are exhibited by colored 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 the 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 the flame their peculiar colors:
| Chloride of Soda (common salt) | Yellow. |
| “ of Potash | Pale violet. |
| “ of Lime | Brick red. |
| “ of Strontia | Bright crimson. |
| “ of Lithia | Red. |
| “ of Baryta | Apple green. |
| “ of Copper | Bluish green. |
| Borax | Yellow. |
Or either of the above salts may be mixed with spirit of wine, as directed, for Red Fire.
Burn spirit of wine on chloride of calcium, a substance obtained by evaporating muriate of lime to dryness.
Burn spirit of wine on a little powdered nitrate of silver.
Heat together potassium and sulphur, and they will instantly burn very vividly.
Heat a little nitre on 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.
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 the bright side of the pot.
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 colors, 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.
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.
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 colored 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 vapor may thus be made to drive nearly all of 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.
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.
A beautiful green fire may be thus made: Take of flour of sulphur thirteen parts, nitrate of baryta seventy-seven, chlorate of potash 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.
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.
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. If the paper be strained over a cylinder of wood it is quickly scorched.
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 to the heat, and that the hand is touching anybody. Then remove one hand to water that causes the thermometer to rise to two hundred 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. Then you will find 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 two hundred degrees, the water at ninety degrees will feel cool. If, therefore, the touch in this case be trusted, the same water will be judged to be hot and cold at the same time.
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.
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-colored flame, and entirely dissolve.
Fill a large glass tube with water, and throw into it a few particles of bruised amber or shreds of litmus; 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 center, and to descend towards the circumference of the tube. These currents will soon become rapid in their motions, and continue till the water boils.
Pour into a glass tube, about ten inches long and one inch in diameter, a little water colored with pink or other dye; then fill it up gradually and carefully with colorless water, so as not to mix them; apply heat at the bottom of the tube, and the colored water will ascend and be diffused throughout the whole.
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, 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 seem 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.
This pretty toy may be purchased at any optician’s for seventy-five cents. It consists of a cup in which is placed a human standing figure concealing a syphon or bent tube, with one end longer than the other. This rises in one leg of the figure to reach the chin, and descends through the other leg, through the bottom of the cup to a reservoir beneath. If you pour water in the cup it will rise in the shorter leg by its upward pressure, driving out the air before it through the longer leg; and when the cup is filled above the bend of the syphon, that is, level with the chin of the figure, the pressure of the water will force it over into the longer leg of the syphon, and the cup will be emptied, the toy thus imitating Tantalus, of mythology, who is represented by the poets as punished in Erebus with an insatiable thirst, and placed up to the chin in a pool of water, which, however, flowed away as soon as he attempted to taste it.
Fill a glass tumbler with water, throw upon its surface a few fragments or thin shavings of camphor, and they will instantly begin to move, and acquire a motion both progressive and rotary, which will continue for a considerable time. During these rotations if the water be touched by any substance which is at all greasy, the floating particles will quickly dart back, and, as if by a stroke of magic, be instantly deprived of their motion and vivacity.
In like manner, if thin slices of cork be steeped in sulphuric ether in a closed bottle for two or three days, and then placed upon the water, they will rotate for several minutes, like the camphor, until the slices of cork, having discharged all their ether, and become soaked with water, they will keep at rest.
If the water be made hot the motion of the camphor will be more rapid than in cold water, but it will cease in proportionately less time. Thus, provide two glasses, one containing water at fifty-eight degrees, and the other at two hundred and ten degrees; place raspings of camphor upon each at the same time; the camphor in the first glass will rotate for about five hours, until all but a very minute portion has evaporated, while the rotation of the camphor in the hot water will last only nineteen minutes. About half the camphor will pass off and the remaining pieces, instead of being dull, white and opaque, will be vitreous and transparent, and evidently soaked with water. The gyrations, too, which at first will be very rapid, will gradually decline in velocity until they become quite sluggish.
The stilling influence of oil upon waves has become proverbial. The extraordinary manner in which a small quantity of oil instantly spreads over a very large surface of troubled water, and the stealthy manner in which even a rough wind glides over it must have excited the admiration of all who have witnessed it.
By the same principle a drop of oil may be made to stop the motion of the camphor, as follows: Throw some camphor, both in slices and in small particles, upon the surface of water, and while they are rotating dip a glass rod into oil of turpentine. Then allow a single drop thereof to trickle down the inner side of the glass to the surface of the water. The camphor will instantly dart to the opposite point of the liquid surface, and cease to rotate.
If a few drops of sulphuric or muriatic acid be let fall into the water, they will gradually stop the motion of the camphor, but if camphor be dropped into nitric acid, diluted with its own bulk of water, it will rotate rapidly for a few seconds and then stop.
If a piece of the rotating camphor be attentively examined with a lens, the currents of the water can be well distinguished, jetting out, chiefly from the corners of the camphor, and bearing it round with irregular force.
The currents, as given out by the camphor, may also be seen by means of the microscope; a drop or two of pure water being placed upon a slip of glass, with a particle of camphor floating upon it. By this means the current may be detected, and it will be seen that they cause the rotations.
A flat watch-glass may be employed, raised a few inches and supported on a wire ring, kept steady by thrusting one end into an upright piece of wood like a retort stand. Then put the camphor and water in the watch-glass, and place under the frame a sheet of white paper, so that it may receive the shadow of the glass, camphor, etc., to be cast by a steady light, placed above, and somewhat on one side of the watch-glass.
On observing the shadow, which may be considered a magnified representation of the object itself, the rotations and currents can be distinguished.
Put thirty grains of phosphorus into a bottle which contains three or four ounces of water. Place the vessel over a lamp and give it a boiling heat. Balls of fire will soon be seen to issue from the water after the manner of an artificial firework, attended with the most beautiful coruscations.
Make a piece of steel red in the fire, then hold it with a pair of pincers or tongs; take in the other hand a stick of brimstone and touch the piece of steel with it. Immediately after their contact you will see the steel melt and drop like a liquid.
Put into a phial some sulphuric ether, color it red with alkanet, then saturate the tincture with spermaceti. This preparation is solid ten degrees above freezing point, and melts and boils at twenty degrees. Place the phial which contains it in a lady’s hand and tell her that if in love, the solid mass will dissolve. In a few minutes the substance will become fluid.
To accomplish this seemingly incredible act requires the following preparation: You must take an egg and soak it in strong vinegar, and in process of time its shell will become quite soft so that it may be extended lengthways without breaking; then insert it into the neck of a small bottle, and by pouring cold water upon it, it will reassume its former figure and hardness. This is really a complete curiosity, and baffles those who are not in the secret to find out how it is accomplished. If the vinegar used to saturate the egg is not sufficiently strong to produce the required softness of shell, add one teaspoonful of strong acetic acid to every two tablespoonfuls of vinegar. This will render the egg perfectly flexible, and of easy insertion into the bottle, which must then be filled with cold water.
Take two small glass jars and close them with corks. In each of these pierce two holes and introduce a glass tube curved in the form of a lengthened V. The two extremities of this tube must not reach further than just a little below the inner surface of the corks. In one jar pour water until it is three-quarters full, and pass through the second hole of the cork a straight glass tube, open at both ends and reaching nearly the bottom. This jar must be hermetically corked. (If necessary, seal the top.) In the other jar put some chalk, and in the second hole of the cork, left free, pass the extremity of a paper funnel in which you place a pellet of wax or putty.
Your apparatus thus being ready, through the funnel pour some vinegar, or better still, some sulphuric acid. The latter ingredient coming in contact with the chalk, forms carbonic acid, which, not being able to escape through the funnel closed by the pellet, passes through the curved tube into the other jar and is dissolved in the water.