When fumigating oak picture frames, first remove the pictures, glass, and gilt slips, then glasspaper the frames to free them from glue, grease, etc., and so arrange them in a box that the fumes will play freely round every part. The ammonia, in liquid form, specific gravity "880, must be poured into saucers or shallow dishes, the box closed up, and every crevice pasted over with brown paper to prevent the fumes escaping; 1/2 pt. is sufficient for a box 9ft. long, 6ft. high by 3ft. wide. The time of exposure varies according to the tone desired, generally from twelve to twenty-lour hours. If possible, insert a pane of glass through which the action of the fumes may be watched. Wiping the frames over with strong coffee or lime-water will produce a tone closely resembling fumed work.