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Diagrams of Experiments: Hydraulic

A curious Hydraulic Experiment, called the Magical Bottle. Take a small bottle, (see Plate) AB, Fig. 9, the neck of which must be very narrow, and provide a glass vessel, CD, the height of which exceeds that of the bottle about two inches; fill the bottle, by means of a small funnel, with red wine, and place it in the vessel CD, which is to be previously filled with water. Then, if the bottle be uncorked, the wine will presently come out of it, and rise in form of a small column, to the surface of the water; and at the same time the water entering the bottle, will supply the place of wine; for water being specifically heavier than wine, it will consequently subside to the lowest place, while the other naturally rises to the top.

A similar effect will be produced, if the bottle be filled with water, and the vessel with wine, for the bottle being placed in the vessel, in an inverted position, the water will descend to the bottom of the vessel, and the wine will rise in the bottle The same effect may also be produced by any other liquors, the specific gravities of which are considerably different.

Another Hydraulic Experiment, called the Miraculous Vessel. Take a tin vessel of about six inches in height, and three in diameter, having a mouth of only a quarter of an inch wide, and in the bottom of the vessel make a number of small holes, of a size sufficient to admit a common sewing needle. Plunge the vessel into water, with its mouth open, and when it is full, cork it, and take it out again; then, as long as the vessel remains corked, no water will come out of it; but as soon as it is uncorked, the water will immediately issue from the small holes at the bottom. It must be observed, however, that if the holes at the bottom of the vessel be more than one-sixth of an inch in diameter, or if they be too numerous, the experiment will not succeed; for, in this case, the pressure of the air against the bottom of the vessel will not be sufficient to confine the water.

A curious Hydraulic Experiment, called Tantalus's Cup. Take a glass, or any other vessel, (see Plate) ABCD, fig. 10. which has a small bent pipe, EFG, open at each end, running through the middle of it; then, if water or wine be poured into the glass, it will continue in it till the tube is full up to the bend F, which should be a little lower than the upper edge of the glass; but if, after this, you continue to pour more liquor into it, it will endeavour, as usual, to rise higher in the glass, but not finding room for a farther ascent in the tube, it will descend through the part EG, and run out at the end G, as long as you continue to put it in. To those who are unacquainted with the nature of the syphon, the effect may perhaps appear something more extraordinary, if the longest branch of the tube be concealed in the handle of the cup.

This is called the cup of Tantalus, from its resemblance to an experiment of the same kind, by placing an upright image in the cup, and disposing the syphon in such a manner that, as soon as the water rises to the chin of the image, it will begin to run out through the longest leg, in the same manner as from the cup above-mentioned.

A curious Chemical Experiment, called the Tree of Diana. Make an amalgam, without heat, of two drachms of leaf silver with one drachm of quicksilver. Dissolve this amalgam 1 of two ounces, or a sufficient quantity, of pure nitrous acid of moderate strength: dilute the solution in about a pcund and a half of distilled water, agitate the mixture, and preserve it for use in a glass bottle with a ground stopper. When you would make your tree, put into a phial the quantity of an ounce of the above preparation, and add to it about the size of a pea of amalgam of gold or silver, as soft as butter: the vessel must then be left at rest, and soon afterwards smali filaments will appear to issue out of the ball of amalgam, which quickly increase, and shoot out branches in the form of shrubs.

A metallic arborisation, somewhat similar, may be produced in the following manner:- Dissolve a little sugar of lead in water, and fill a phial with the solution. Pass a wire through the cork, and affix to the upper part of the wire a small bit of silver, or zinc, in such a manner that it may be immersed in the solution not far from its surface. Set the phial in some place where it may remain undisturbed, and in about twentyfour hours you will perceive the lead beginning to shoot round the wire: this process will continue going on slowly, till you have a beautiful metallic tree. If you have a wide-mouthed phial, or glass jar, the experiment may be pleasingly diversified, by arranging the wire in various forms. A remarkable Experiment, called Prince Rupert's Drops. Take up a small quantity of the melted matter of glass with a tube, and let a drop of it fall into a vessel of water. This drop will have a small tail, which, being broken, the whole substance of the drop will burst, with great violence, in a fine powder, and give a little pain to the hand, but do no hurt to it. It is a remarkable circumstance in this experiment, that the bulb, or body, will bear the stroke of a hammer, without breaking; but when the tail is broken, the above-mentioned effect is produced. If the drop be cooled in the air, the same effect will not take place; and if it be ground away on a stone, nothing extraordinary appears; but if it be put into the receiver of an air-pump, and then broken, the effect will be so violent as to produce light.

How to make Sympathetic Inks of various Kinds.

By sympathetic inks, are meant those kinds of liquors, with. which if any characters be written, they will remain invisible, till some method is used to give them a colour.

The first class of these inks consists of such as become visible by passing another liquor over them, or by exposing them to the vapour of that liqu r.

The second, of those which do not appear so long as they are kept close, but soon become visible on being exposed to the air.

The third, of such as become apparent by strewing or sifting some very fine powder over them. The fourth, of those which do not become visible till they are exposed to the fire, or heated.

The fifth, like the fourth, of such as appear by heat, but disappear again when the paper becomes cold, or has had a sufficient time to imbibe the moisture of the air.

Sympathetic Inks of the First Class. - Put some litharge into strong distilled vinegar, and let it stand for twenty-four hours; then strain it off, and, after it is quite settled, put it into a bottle closely corked, and preserve it for use. Having done this, put into a pint bottle two ounces of quicklime, one ounce of orpiment in powder, and as much water as will rise two or three fingers' breadth above them; and when the solution is made, pour the liquid gently off, and let it stand in the sun for two or three days, observing to turn it five or six times each day.

When these liquors are ready for use, any letters written by the first, being exposed to the vapours of the second, will quickly become visible; and if you would have them disappear again, you must draw a sponge, or pencil, dipt in aquafortis, or spirit of nitre, over them: and if, after this, you would have them appear again, stay till the paper is quite dry, and then pass the vivifying liquor, made of the solution of orpiment, over them, as before. Another Ink of this Class-Dissolve bismuth in the nitrous acid, and any letters written with this ink will become quite black, by being exposed to the vapour of liver of sulphur, which is of so penetrating a nature, that it will act upon the ink through a quire of paper, or even the slight partition of a room.