Oxide Layer on a Polished Surface

I CAN confirm S. Dobinski's results1 for copper by my own experiments on polished aluminium2. I used a different method, namely, observations of changes in the initial solution potential when polished under paraffin, benzene, water. The conclusion I came to in my paper was that wet " polishing resulted in the formation of an oxide film in close contact with the metal and similar to that formed by heating in air". This seems further evidence that many observations on the so-called amorphous layer may really have been observations on the properties of the oxide.