To clean and renovate bronze ornaments that have gone dull and rough, try brushing the articles with a fine brush and powdered pumice-stone and water; if this does not have the desired effect, they will have to be dipped, cleaned, and re-bronzed. Well boil them in a solution made by dissolving 1/2 lb. of caustic potash in lgal. of water, then dip them in clean water and dry. Any rough places must be smoothed down with a fine file or fine emery-cloth. Now dip the articles in an acid bath, wash, and dry. Make up a solution consisting of 1 gal. of water and 2 1/2 oz. of iron perchloride or nitrate of iron, the latter for preference. When the iron salt has dissolved, immerse the bronzes for a short time; if not satisfactory, continue the immersion till the desired shade is obtained. The above solution will give any shade from brown to black. When the articles are quite dry, they may be preserved from further damp by coating with a very pale lacquer.