When I was in high school, I and other students checked into our science class on the first day of the new semester.
One of the first things the teacher of the class did was warn us against drinking Coca-Cola. Then, he opened a bottle of Coke, dropped a shiny new nail into the liquid, snapped the cap back on the bottle and placed it atop a cabinet.
Well, that full bottle of soda with the nail in it remained on the cabinet for the entire semester -- and on the last day of school before summer vacation, the teacher removed the bottle from off the cabinet, opened it and poured all of the liquid into a sink.
Then, the once shiny new nail came out and the teacher held it up for all of us to see it.
We were shocked. The nail looked like some ancient relic that had been dug up from an archaeological site. It was a rusty dark brown-black color and all gnarled up. It looked like it had been around for thousands of years.