Part 5 (1/2)

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 s.h.i.+nes 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 s.h.i.+ne 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.