This section is from the "Henley's Twentieth Century Formulas Recipes Processes" encyclopedia, by Norman W. Henley and others.
Recent stains of picric acid may be removed readily if the stain is covered with a layer of magnesium carbonate, the carbonate moistened with a little water to form a paste, and the paste then rubbed over the spot.
II. —Apply a solution of
Boric acid.......... 4 parts
Sodium benzoate.... 1 part Water............. 100 parts
III. —Dr. Prieur, of Besanšon, recommends lithium carbonate for the removal of picric-acid stains from the skin or from linen. The method of using it is simply to lay a small pinch on the stain, and moisten the latter with water. Fresh stains disappear almost instantly, and old ones in a minute or two.