Part 307

See also Dyes.

«Mordant for Cement Surfaces.»—Take green vitriol and dissolve it in hot water. If the cement is rather fresh add 1 part of vinegar for each part of green vitriol. Best suited, however, is triple vinegar (vinegar containing 11⁠/⁠13 per cent of acetic acid), which is alone sufficient for well-dried places. For such surfaces that have been smoothed with a steel tool and have hardly any pores, take alcohol, 1 part, and green vitriol, 10 parts, and apply this twice until the iron has acquired a yellowish color. This mordant forms a neutral layer between cement and paint, and causes the latter to dry well.

«Mordant for Gold Size.»—A mordant for gold size gilding that has been thoroughly tested and found to be often preferable to the shellac-mixed article, is prepared from yolk of egg and glycerine, The yolk of an egg is twirled in a cup and up to 30 drops of glycerine are added to it. The more glycerine added, the longer the mordant will take to dry. Or else an equal portion of ordinary syrup is mixed with the yolk of egg. Same must be thinly liquid. If the mass becomes too tough it is warmed a little or thinned with a few drops of warm water. A single application is sufficient. Naturally, this style of gilding is only practicable indoors; it cannot withstand the influence of moisture.

«MORTAR, ASBESTOS.»

Asbestos mortar consists of a mixture of asbestos with 10 per cent of white lime. Canadian asbestos is generally used, which is composed of 80 per cent of asbestos and 20 per cent of serpentine. The asbestos is ground and the coarse powder used for the first rough cast, while the finer material is employed for the second top-plastering. This mortar is highly fire-resisting and waterproof, is only half as heavy as cement mortar, and tough enough to admit of nails being driven in without breaking it.

MOSQUITO REMEDIES: See Insecticides.

MOSS REMOVERS: See Cleaning Preparations and Methods, under Miscellaneous Methods.

MOTHS: See Turpentine.

MOTH PAPER: See Paper.

MOTH TRAPS AND MOTH KILLERS: See Household Formulas.

MOTHER-OF-PEARL: See Pearl.

MOTORS, ANTI-FREEZING SOLUTION FOR: See Freezing Preventives.

«MOUNTANTS:»

See also Adhesives and Photography.

«Mounting Drawings, Photos, etc., upon Fine Pasteboard.»—It frequently happens that the pasteboard will warp toward the face of the picture, even if left in a press till the gluing medium is perfectly dry. This fault can be {480} obviated by moistening the back of the pasteboard moderately with a sponge, and, while this is still wet, pasting the picture on with good, thin glue. If moistening the pasteboard is impracticable (with sensitive drawings, paintings, etc.), paste which has been pressed through a fine cloth is rubbed on, always in the same direction, and the picture is carefully and evenly pressed on. Then bend the pasteboard backward in a wide semicircle, and place it between two heavy objects on the table. After a few hours, when the paste is completely dry, put the picture down flat and load proportionately. Papers of large size, which cannot conveniently be placed between two objects, are wrapped up, and twine is stretched around, thus keeping them bent.

«Mounting Prints on Glass.»—Take 4 ounces of gelatin; soak 1⁠/⁠2 hour in cold water; then place in a glass jar, adding 16 ounces of water; put the jar in a large dish of warm water and dissolve the gelatin. When dissolved pour in a shallow tray; have the prints rolled on a roller, albumen side up; take the print by the corners and pass rapidly through the gelatin, using great care to avoid air bubbles. Squeeze carefully onto the glass. The better the quality of glass, the finer the effect.

MOUTH ANTISEPTICS: See Antiseptics.

MOUTH WASHES: See Dentifrices.

MOVING OBJECTS AND HOW TO PHOTOGRAPH THEM: See Photography.

MUCILAGE: See Adhesives.

«MUSIC BOXES.»

Care must be exercised in taking apart, for if the box is wound up and the fly is removed, the cylinder is ruined. The spring relaxes at a bound, causing the cylinder to turn with such rapidity that the pins cannot resist the teeth, whose force is intensified by the velocity of the cylinder. The pins originally bent forward are broken, or pressed backwards; as they are hardened, they cannot be bent forward again without breaking. This accident involves the cost of a new cylinder, the most expensive part of the apparatus. Besides, the comb almost always loses some teeth and the wheel-work also suffers in its turn.

To avoid such mishaps the careful operator will take the parts asunder in the following order:

1. Remove the comb.

2. Take the apparatus from the box and completely disarm the spring.

3. Remove the barrel.

4. Remove the escapement.

5. Remove the cylinder.