METHOD OF COLORING ALUM CRYSTALS.
In making these crystals the coloring should be added to the solution of alum in proportion to the shade which it is desired to produce. Coke, with a piece of lead attached to it in order to make it sink in the solution, is a good substance for a nucleus, if a cluster of crystals are to be formed. Any form, if wound around with knitting cotton, can be used, or the grasses above described can be dipped in these colored solutions, and very pretty results obtained.
Yellow: muriate of iron. Blue: solution of indigo in sulphuric acid. Pale blue: equal parts of alum and blue vitriol. Crimson: infusion of madder and cochineal. Black: Japan ink thickened with gum. Green: equal parts of alum and blue vitriol, with a few drops of sulphate of iron. Milk white: a crystal of alum held over a glass containing ammonia will become a milky white color upon its surface.
[Note.—To make an infusion of a substance you simply pour boiling water over it. The madder and cochineal are in the dry form, and only a little water should be used, as too much will make the color less brilliant.]
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ANIMATED FIRE.
When small pieces of camphor are placed in a basin of pure water, a very peculiar motion commences; some of the pieces turn as if on an axis, others go steadily round the vessel, some seem to be pursuing others, and thus they continue forming a very curious and pleasing appearance; but if a single drop of sulphuric acid be put into the water, the motion of the camphor instantly stops. If a piece of camphor be lighted, and then carefully placed on the water, it burns with a bright flame, moving about with great rapidity, as if in search of something, but is instantly stopped by a drop of sulphuric acid.
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A PRETTY ORNAMENT FOR A BOY TO MAKE.
Dissolve in seven different tumblers containing warm water, half ounces of sulphates of iron, copper, zinc, soda, alumina, magnesia, and potash. Pour them all, when completely dissolved, into a large flat dish, and stir the whole with a glass rod or bit of broken glass for a while. Place the dish in a warm place where it will be free from dust and will not be shaken. After due evaporation has taken place, the whole will begin to shoot out into crystals. These will be of various colors and forms, some little ones being gathered together in small groups, and other larger ones scattered throughout the whole fluid. By a little careful study you will soon be able to distinguish each crystal separately, from its peculiar form and color, thus learning an interesting lesson in chemistry, while making a beautiful ornament for your room. Be sure and preserve it carefully from the dust.