LAUGHING GAS.

THE above fanciful appellation has been given to nitrous oxide, from the very agreeable sensations excited by inhaling it. In its pure state it destroys animal life, but loses this noxious quality when inhaled, because it becomes blended with the atmospheric air which it meets in the lungs. This gas is made by putting three or four drams of nitrate of ammonia, in crystals, into a small glass retort, which being held over a spirit lamp, the crystals will melt, and the gas be evolved.

Having thus produced the gas, it is to be passed into a large bladder having a stop-cock; and when you are desirous of exhibiting its effects, you cause the person who wishes to experience them, to first exhale the atmospheric air from the lungs, and then quickly placing the cock in his mouth, you turn it, and bid him inhale the gas. Immediately, a sense of extraordinary cheerfulness, fanciful flights of imagination, an uncontrollable propensity to laughter, and a consciousness of being capable of great muscular exertion, supervene. It does not operate in exactly the same manner on all persons; but in most cases the sensations are agreeable, and have this important difference from those produced by wine or spirituous liquors, that they are not succeeded by any depression of mind.

THE LUMINOUS WAND.

Cover a long slip of wood, half-way, with sulphur, by immersion while in a melted state. Having prepared a jar of nitrous oxide gas, as in preceding experiments, light the sulphur, and plunge the wand into the jar. The gas will extinguish the flame. Withdraw the wand, light it again, and when the flame is very brilliant, immerse it again in the jar. It will this time burn with great splendour, and of a beautiful red colour.

TO MAKE CARBONIC ACID GAS.

Put about an ounce of marble in small lumps, into an eight ounce phial, with about an equal quantity of water; pour in a little muriatic acid, and carbonic acid gas will be evolved.

CARBONIC ACID GAS IN WINE OR BEER VESSELS.

The apparently empty or upper part of vessels in which wine or beer is working, is filled with this deleterious gas; for its great weight prevents its ascent from the fermenting liquid. A variety of striking but simple experiments may be made with the gas in this condition. Lighted paper, or a candle dipped into it, will be immediately extinguished; and the smoke remaining in the carbonic acid gas will render its surface visible, which may be thrown into waves by agitation, like water. In consequence of the great weight of the carbonic acid gas, it may be taken from a vat of fermenting liquor, in a jug or bottle, and in the latter, if well corked, it may be conveyed to great distances; or the gas may be drawn out of a vessel by a cock, like a liquid.