A new anodic method for the transfer of oxide films from heat‐tinted iron to glass or plastic

In the new anodic method, the specimen carrying the oxide film to be transferred is cemented to glass, and the whole of the metal is dissolved away by anodic action, leaving the film attached to the glass. The method has the advantage that large areas of films are transferred to a rigid, transparent support, without any doubt as to which of the two surfaces represents the outer surface of the film as present on the metal. The area of the pieces transferred can be measured, and the metal (or metals) in the films estimated by microanalysis; alternatively by transferring to glass coated with petroleum jelly, the wrinkling or curling of the film gives information about the stresses present in the films when they are clinging to the metal. The validity of the method is shown by the fact that the transparency and appearance of the film depend on the temperature and time of the heating of the metal but are independent of the electrical conditions in the cell.