This section is from the "Henley's Twentieth Century Formulas Recipes Processes" encyclopedia, by Norman W. Henley and others.
A stain produced by the embedding of grains of gunpowder in the skin is practically the same thing as a tattoo mark. The charcoal of the gunpowder remains unaffected by the fluids of the tissues, and no way is known of bringing it into solution there. The only method of obliterating such marks is to take away with them the skin in which they are embedded. This has been accomplished by the application of an electric current, and by the use of caustics. When the destruction of the true skin has been accomplished, it becomes a foreign body, and if the destruction has extended to a sufficient depth, the other foreign body, the coloring matter which has been tattooed in, may be expected to be cast off with it.
Recently pepsin and papain have been proposed as applications to remove the cuticle. A glycerole of either is tattooed into the skin over the disfigured part; and it is said that the operation has proved successful.
It is scarcely necessary to say that suppuration is likely to follow such treatment, and that there is risk of scarring. In view of this it becomes apparent that any such operation should be undertaken only by a surgeon skilled in dermatological practice. An amateur might not only cause the patient suffering without success in removal, but add another disfigurement to the tattooing.
Carbolic acid has been applied to small portions of the affected area at a time, with the result that the powder and skin were removed simultaneously and, according to the physician reporting the case, with little discomfort to the patient.
Rubbing the affected part with moistened ammonium chloride once or twice a day has been reported as a slow but sure cure.