If a grain of this powder, put into a spoon, (it should be an iron one,) be exposed to the flame of a candle, it will explode with a very loud report.

_To melt a piece of Money in a Walnut-sh.e.l.l, without injuring the sh.e.l.l._

Bend any thin coin, and put it into half a walnut-sh.e.l.l; place the sh.e.l.l on a little sand, to keep it steady. Then fill the sh.e.l.l with a mixture made of three parts of very dry pounded nitre, one part of flowers of sulphur, and a little saw-dust well sifted. If you then set light to the mixture, you will find, when it is melted, that the metal will also be melted at the bottom of the sh.e.l.l, in form of a b.u.t.ton, which will become hard when the burning matter round it is consumed: the sh.e.l.l will have sustained very little injury.

_A Liquid that Shines in the Dark._

Take a bit of phosphorus, about the size of a pea; break it into small parts, which you are to put into a gla.s.s half full of very pure water, and boil it in a small earthen vessel, over a very moderate fire. Have in readiness a long narrow bottle, with a well-fitted gla.s.s stopper, and immerse it, with its mouth open, into boiling water. On taking it out, empty the water, and immediately pour in the mixture in a boiling state; then put in the stopper, and cover it with mastich, to prevent the entrance of the external air.

This water will shine in the dark for several months, even without being touched; and, if it be shaken in dry warm weather, brilliant flashes will be seen to rise through the middle of the water.

_Luminous Liquor._

Put a little phosphorus, with essence of cloves, into a bottle, which must be kept closely stopped. Every time the bottle is unclosed, the liquor will appear luminous. This experiment must be performed in the dark.

_The changeable Rose._

Take a common full-blown rose, and, having thrown a little sulphur finely pounded into a chafing-dish with coals, expose the rose to the vapour. By this process the rose will become whitish; but if it be afterwards held some time in water, it will resume its former colour.

_Golden Ink._

Take some white gum arabic, reduce it to an impalpable powder, in a bra.s.s mortar; dissolve it in strong brandy, and add a little common water to render it more liquid. Provide some gold in a sh.e.l.l, which must be detached, in order to reduce it to a powder. When this is done, moisten it with the gummy solution, and stir the whole with a small hair-brush, or your finger; then leave it for a night, that the gold may be better dissolved. If the composition become dry during the night, dilute it with more gum water, in which a little saffron has been infused; but take care that the gold solution be sufficiently liquid to flow freely in a pen. When the writing is dry, polish it with a dry tooth.

_Another way._

Reduce gum ammoniac into powder, and dissolve it in gum arabic water, to which a little garlic juice has been added. This water will not dissolve the ammonia so as to form a transparent liquid; for the result will be a milky liquor. With the liquor form your letters or ornaments on paper or vellum, with a pen or fine camels'-hair brush; then let them dry, and afterwards breathe on them some time, till they become moist; then apply a few bits of leaf gold to the letters, which you press down gently with cotton wool. When the whole is dry, brush off the superfluous gold with a large camels'-hair brush, and, to make it more brilliant, burnish with a dog's tooth.

_White Ink, for Writing on black Paper._

Having carefully washed some egg-sh.e.l.ls, remove the internal skin, and grind them on a piece of porphyry. Then put the powder into a small vessel of pure water, and when it has settled at the bottom, draw off the water, and dry the powder in the sun. This powder must be preserved in a bottle; when you want to use it, put a small quant.i.ty of gum ammoniac into distilled vinegar, and leave it to dissolve during the night. Next morning the solution will appear exceedingly white; and if you then strain it through a piece of linen cloth, and add to it the powder of egg-sh.e.l.ls, in sufficient quant.i.ty, you will obtain a very white ink.

_To construct Paper Balloons._

Take several sheets of silk paper; cut them in the shape of a spindle; or, to speak more familiarly, like the coverings of the sections of an orange; join these pieces together, into one spherical or globular body, and border the aperture with a ribbon, leaving the ends, that you may suspend them from the following lamp.

Construct a small basket of very fine wire, if the balloon is small, and suspend it from the aperture, so that the smoke from the flame of a few leaves of paper, wrapped together, and dipped in oil, may heat the inside of it. Before you light this paper, suspend the balloon in such a manner, that it may, in a great measure, be exhausted of air, and as soon as it has been dilated, let it go, together with the wire basket, which will serve as ballast.

_Water-Gilding upon Silver._

Take copper-flakes, on which pour strong vinegar; add alum and salt in equal quant.i.ties; set them on a fire, and when the vinegar is boiled, till it becomes one-fourth part of its original quant.i.ty, throw into it the metal you design to gild, and it will a.s.sume a copper colour.

Continue boiling it, and it will change into a fine gold colour.

_A Water which gives Silver a Gold Colour._

Take sulphur and nitre, of each an equal quant.i.ty; grind them together very fine, and put them into an unglazed vessel; cover and lute it well; then set it over a slow fire for 24 hours; put what remains into a strong crucible, and let it dissolve; put it into a phial, and whatever silver you anoint with it will have a gold colour.

_To make an old Gold Chain appear like new._

Dissolve sal ammoniac in urine, boil the chain in it, and it will have a fine gold colour.

_To give Silver the Colour of Gold._

Dissolve in common aqua fortis as much silver as you please. To eight ounces of silver, take four ounces of hepatic aloes, six ounces of turmeric, and two ounces of prepared tutty, that has been several times quenched in urine. Put these to the solution of the silver; they will dissolve, but rise up in the gla.s.s like a sponge; this gla.s.s must therefore be large, to prevent running over. Then draw it off, and you will have ten ounces of silver as yellow as gold.

_A Water to give any Metal a Gold Colour._

Take fine sulphur and pulverize it; then boil some stale spring water; pour it hot upon the powder, and stir it well together; boil it again, and pour into it an ounce of dragon's blood. After it is well boiled, take it off, and filter it through a fine cloth; pour this water into a matra.s.s, (a chemical vessel,) after you have put in what you design to colour; close it well, and boil it a third time, and the metal will be a fine gold colour.

_Another way._

Take hepatic aloes, nitre, and Roman vitriol, of each equal quant.i.ties; and distil them with water, in an alembic, till all the spirits are extracted; it will at last yield a yellowish water, which will tinge any sort of metal of a gold colour.

_To give Silver-plate a l.u.s.tre._

Dissolve alum in a strong ley, and sc.u.m it carefully; then mix it up with soap, and wash your silver utensils with it, using a linen rag.

_The Fiery Fountain._

If twenty grains of phosphorus, cut very small, and mixed with forty grains of powder of zinc, be put into four drachms of water, and two drachms of concentrated sulphuric acid be added thereto, bubbles of inflamed phosph.o.r.etted hydrogen gas will quickly cover the whole surface of the fluid in succession, forming a real fountain of fire.

_To take Impressions of Coins, Medals, &c._

Cut fish-glue, or isingla.s.s, into small pieces, immerse it in clear water, and set it on a slow fire; when gradually dissolved, let it boil slowly, stirring it with a wooden spoon, and taking off the sc.u.m.

The liquor being sufficiently adhesive, take it off the fire, let it cool a little, and then pour it on the medal or coin you wish to copy, having first rubbed the coin over with oil. Let the composition lay about the thickness of a crown-piece on the medal. Then set it in a moderate air, neither too hot nor too cold, and let it cool and dry.

When it is dry, it will loosen itself; you will find the impression correct, and the finest strokes expressed with the greatest accuracy.

You may give a most pleasing effect to the composition, by mixing any colour with it, red, yellow, blue, green, &c., and if you add a little parchment size to it, it will make it harder and better. This size is made by gently simmering the cuttings of clear white parchment in a pipkin, with a little water, till it becomes adhesive.

_To tell a Person any Number he may privately fix on._

When the person has fixed on a number, bid him double it and add four to that doubling; then multiply the whole by 5; to the product let him add 12, and multiply the amount by 10. From the total of all this, let him deduct 320, and tell you the remainder; from which, if you cut off the two last figures, the number that remains will be what he fixed upon. For instance,