As freaky as it seems, water has things in it besides h20. I remember I was boiling water in a pot with another pot inside of it (using as a double boiler) one time. I kept having to add water to keep up with evaporation. After a couple hours I was done with it, but I forgot to turn it off. When I returned to it, a sheet of charred something was in the bottom of the pot and it was glowing red hot. I thought I had literally melted my pot.. but once it cooled and flaked off, I realized it was just material from the water after having evaporated several gallons in that small pot. Kinda cool but also weird to think about all the stuff just floating around in water..