QUADRUPLE TRANSMUTATION. Dissolve a small piece of nickel in nitric acid, and it will appear of a fine grass-green colour; add to it a little ammonia, and a blue precipitate will be formed; this will change to a purplered in a few hours, and the addition of any acid will convert it to an apple-green. QUINTUPLE TRANSMUTATION. Heat potassium over the flame of a spirit-lamp, and the colour will change from white to a bright azure, thence to a bright blue, green, and olive. COMBINATION OF COLOURS. Cut out a disc or circle of pasteboard, and cover it with paper half green and half black: cause the disc to be rapidly turned round, (like the shafts of a toy wind-mill,) and the colours will combine and produce white. UNION OF TWO METALS WITHOUT HEAT. Cut a circular piece of gold leaf, called, "dentist's gold," about half an inch in diameter; drop upon it a globule of mercury, about the size of a small pea, and if they be left for a short time, the gold will lose its solidity and yellow colour, and the mercury its liquid form, making a soft mass, of the colour of mercury. MAGIC BREATH. Half fill a glass tumbler with lime water; breathe into it frequently, at the same time stirring it with a piece of glass. The fluid, which before was perfectly transparent, will presently become quite white, and, if allowed to remain at rest, real chalk will be deposited. TWO BITTERS MAKE A SWEET. It has been discovered, that a mixture of nitrate of silver with hypo-sulphate of soda, both of which are remarkably bitter, will produce the sweetest known substance. VISIBLE AND INVISIBLE. Write with French chalk on a looking-glass; wipe it with a handkerchief, and the lines will disappear; breathe on it, and they will re-appear. This alternation will take place for a great number of times, and after the lapse of a considerable period. ARTIFICIAL MIRAGE. HE mirage is an optical phenomenon, produced by the refractive power of the atmosphere. The appearance presented is that of the double image of an object in the air; one of the images being in the natural position, and the other inverted, so as to resemble a natural object and its image in the water. The mirage is commonly vertical, or upright, that is, presenting the appearance, above described, of one object over another, like a ship above its shadow in the water. Sometimes, however, the image is horizontal, or upon the water, and at other times, it is seen on the right or left-hand of the real object, or on both sides. All the effects of the mirage may be represented artificially to the eye. For this purpose, provide a glass tumbler two-thirds full of water, and pour spirit of wine upon it; or pour into a tumbler some syrup, and fill it up with water: as the water and |