Muriatic acid, 1 ounce, Nitric acid, 1/2 ounce, Beeswax.
To write on iron, steel, silver or gold, mix the above acids and use as follows: Cover the place in which you wish to write with melted beeswax, and when the wax is cold, write the name or words plainly with a file-point, or with an etching needle, carrying the writing through the wax, and cleaning all the wax out of the letter.
Then apply the mixed acids with a feather, carefully filling all parts of each letter. Let the acid remain for from 1 to 10 minutes, according to the appearance desired, and then put on some water, which will dilute the acid and stop the process.
Either of the acids separately would cut iron or steel, but it requires the mixture of the two to take hold of either gold or silver. After the acids are washed off it is well to apply a little oil.