The following repertoire of such tricks and illusions will be found exceedingly complete, although pains have been taken to select only the best and most startling of them. A large number are entirely new, but are described with sufficient clearness to enable any person of ordinary intelligence to become expert in them, with a little practice.
Chemical Amusements.
Chemistry is one of the most attractive sciences. From the beginning to the end the student is surprised and delighted with the developments of the exact discrimination, as well as the power and capacity, which are displayed in various forms of chemical action. Dissolve two substances in the same fluid, and then, by evaporation or otherwise, cause them to reassume a solid form, and each particle will unite with its own kind, to the entire exclusion of all others. Thus, if sulphate of copper and carbonate of soda are dissolved in boiling water, and then the water is evaporated, each salt will be reformed as before. This phenomenon is the result of one of the first principles of the science, and as such is passed over without thought; but it is a wonderful phenomenon, and made of no account, only by the fact that it is so common and so familiar.
It is by the action of this same principle, “chemical affinity,” that we produce the curious experiments with
Sympathetic Inks.
By means of these, we may carry on a correspondence which is beyond the discovery of all not in the secret. With one class of these inks, the writing becomes visible only when moistened with a particular solution. Thus, if we write to you with a solution of the sulphate of iron, the letters are invisible. On the receipt of our letter, you rub over the sheet a feather or sponge, wet with a solution of nut-galls, and the letters burst forth into sensible being at once, and are permanent.
2. If we write with a solution of sugar of lead, and you moisten with a sponge or pencil, dipped in water impregnated with sulphureted hydrogen, the letters will appear with metallic brilliancy.
3. If we write with a weak solution of sulphate of copper, and you apply ammonia, the letters assume a beautiful blue. When the ammonia evaporates, as it does on exposure to the sun, the writing disappears, but may be revived again as before.
4. If you write with the oil of vitriol very much diluted, so as to prevent its destroying the paper, the manuscript will be invisible except when held to the fire, when the letters will appear black.
5. Write with cobalt dissolved in diluted muriatic acid; the letters will be invisible when cold, but when warmed they will appear a bluish green.