VALUABLE IN MARKING TOOLS AND INSTRUMENTS.
| Muriatic acid1 | ounce. |
| Nitric acid 1/2 | ounce. |
Cover the portion of metal you wish to write upon with melted beeswax and allow it to cool. Write the inscription plainly with any sharp-pointed instrument through the beeswax to the metal. Apply the acids with a feather or rag, carefully filling each letter, and let it remain from one to thirty minutes, according to the desired depth of the lettering, after which wash off the beeswax and acids and rub over with a little sweet oil to prevent further rust or tarnish.
Ink Powders.
As in the case of fluid inks there are many formulas for preparing ink powders. The following are the best:
Black.—Nut-galls, 1 ounce; copperas, 1/2 ounce; gum Arabic, 7 ounces. Add one clove to this quantity. Or, take negrosine, 1 ounce; dextrine, 3 ounces; mix.
Blue.—Water blue aniline, 1 ounce; dextrine, 5 ounces. Or, soluble Prussian blue, 1/2 ounce; dextrine, 1 ounce.
Green.—Aniline green, 44 parts; gelatine, 4 parts, and lunar caustic, 2 parts. Or, green aniline, 1 part; dextrine, 4 parts.
Red.—Eosine aniline, 1 ounce; dextrine, 1 ounce.
A tea-spoonful to a table-spoonful of the powder is dissolved in 1 pint of water, requiring from 1/2 to 1 hour to make the solution.