I put some aluminium foil and rusted copper(namely a Japanese 10 yen coin) in saturated NaCl solution. After some minutes tiny amount of small bubbles were observed on the surface of the foil. After several hours there appeared white cloudy thing at the bottom of the container. I think this cloudy thing is aluminium hydroxide, but how could this possible? In textbook it is written that aluminium does not react in neutral environment.