One means of removing an expensive crystoleum picture from cracked glass is to use hydrofluoric acid, but much depends on the process by which the picture was produced. Soak the broken glass and picture in water for some little time, then pour off and cover with a 5-per-cent. solution of hydrofluoric acid. After it has remained about a minute, stroke the extreme edges of the glass and gently coax the film to frill, when it may be rolled off the glass. Care must be taken to unroll the film in the same way, or the picture will be reversed. The film will probably expand readily, and if this is objected to, should be brushed over with collodion before stripping. Contraction could also be obtained with methylated spirit, but would be difficult when dealing with so thin a film. Remove the broken glass and insert a sheet of waxed tracing paper underneath the film. Coat the new glass with thin gum (filtered), and lift the tracing paper by the two ends with the film lying on it, and Lay down on the glass; it may then be worked into position, driving out air bubbles with a pad of wool.