MANTLES.
These are prepared after processes differing slightly from one another, but all based on the original formula of Welsbach—the impregnation of vegetable fibers with certain mineral oxides in solution, drying out, and arranging on platinum wire.
| Lanthanum oxide | 30 parts |
| Yttrium oxide | 20 parts |
| Burnt magnesia | 50 parts |
| Acetic acid | 50 parts |
| Water, distilled | 100 parts |
The salts are dissolved in the water, and to the solution another 150 parts of distilled water are added and the whole filtered. The vegetable fiber (in its knitted or woven form) is impregnated with this solution dried, and arranged on platinum wire. In the formula the acetic acid may be replaced with dilute nitric acid. The latter seems to have some advantages over the former, among which is the fact that the residual ash where acetic acid is used has a tendency to ball up and make a vitreous residue, while that of the nitric acid remains in powdery form.
Self-igniting Mantles.
MANURES: See Fertilizers.
MANUSCRIPT COPYING: See Copying.
MAPLE: See Wood.
MARASCHINO: See Wines and Liquors.
MARBLE CEMENTS: See Adhesives.
MARBLE CLEANING: See Cleaning Preparations and Methods.
MARBLE COLORS: See Stone.
MARBLE ETCHING: See Etching.
MARBLE, IMITATION: See Plaster.
MARBLE, PAINTING ON: See Painting.
MARBLE POLISHING: See Polishes.
MARBLING CRAYONS: See Crayons.
MARGERINE: See Butter.