Marble Cleaning.
Rub with muriatic acid diluted with water, care being taken that it is not too strong. Repeat the process till clean, then wash with clear water. When the marble is very dirty, as in the case of old tombstones, use the following:
| Muriatic acid2 | ounces. |
| Acetic acid1 | ounce. |
| Verdigris1 | drachm. |
Mix, apply with a brush, and sponge off with clear water. Repeat until clean, then polish with pumice stone continually moistened with water as you proceed.