MAGIC: See Pyrotechnics.
MAGNESIUM CITRATE.
| Magnesium carbonate | 10 ounces |
| Citric acid | 20 ounces |
| Sugar | 21 ounces |
| Oil of lemon | 1/2 drachm |
| Water enough to make | 240 ounces |
Introduce the magnesium carbonate into a wide-mouthed 2-gallon bottle, drop the oil of lemon on it, stir with a wooden stick: then add the citric acid, the sugar, and water enough to come up to a mark on the bottle indicating 240 ounces. For this purpose use cold water, adding about half of the quantity first, and the remainder when the substances are mostly dissolved. By allowing the solution to stand for a half to a whole day, it will filter better and more quickly than when hot water is used.
MAGNESIUM ORGEAT POWDER: See Salts, Effervescent.
MAGNESIUM FLASH-LIGHT POWDERS: See Photography.
MAGNETIC CURVES OF IRON FILINGS, THEIR FIXATION.
One of the experiments made in every physical laboratory in teaching the elements of magnetism and electricity is the production of the magnetic curves by sprinkling iron filings over a glass plate, after the well-known method.
For fixing these curves so that they may be preserved indefinitely, a plate of glass is warmed on the smooth upper surface of a shallow iron chest containing water raised to a suitable temperature by means of a spirit-lamp. A piece of paraffine is placed on the glass, and in the course of 3 or 4 minutes spreads itself evenly in a thin layer over the surface. The glass plate is removed, the surplus paraffine running off. The image is formed with iron filings on the cooled paraffine, which does not adhere to the iron, so that if the image is unsatisfactory the filings may be removed and a new figure taken. To fix the curves, the plate of glass is again placed on the warming stove. Finally, the surface of the paraffine is covered with white paint, so that the curves appear black on a white ground. Very well-defined figures may thus be obtained. A similar though much simpler process consists in covering one surface of stiff white paper with a layer of paraffine, by warming {465} over an iron plate, spreading the filings over the cooled surface, and fixing them with a hot iron or a gas flame.
MAGNOLIA METAL: See Alloys.