Fill with hydrogen gas a bladder with a cock fixed to it; to which adapt a copper tobacco pipe: dip the bowl, of the pipe into soap-lather; press gently on the bladder filled with inflammable air, and a small soap bubble will issue, which, instead of falling to the ground, will rise most rapidly.
Instead of pure hydrogen gas only, fill the bladder with a mixture of one third of atmospheric air and two thirds of hydrogen gas: and, when they arise in the air, hold a candle to them, and the report will be like that of a pistol.
A Brilliant Blue Flame.
Mix boracic acid in spirits of wine, set the solution on fire, and the above effect will ensue.
An Emerald Green Flame.
Prepare nitrate of copper, thus:—let copper clippings or filings be dissolved in a sufficient quantity of nitric acid, of a moderate strength; when no further effervescence ensues, boil the acid gently upon the copper, until a pellicle appears; decant the solution, evaporate it slowly, and, when a very strong pellicle or skin appears, suffer it to crystallize. The salt is of a fine blue colour. Then cause the alcohol (spirit of wine) to burn upon this nitrate of copper, and it will exhibit a beautiful emerald green colour.
Loud Detonations, like the Discharge of Artillery.
Put into a bottle, not quite transparent, half an ounce of iron filings, over which pour four ounces of pure water; add one ounce of sulphuric acid, and shake the mixture.
If you apply a lighted paper tied to the end of a stick, near the top of the bottle, an instantaneous vivid flame will suddenly dart from the bottom, accompanied by a tolerably loud detonation.
Fifteen or twenty successive loud reports may likewise be obtained, by touching the aperture of the bottle with a lighted wax taper, fastened to a stick.