Don't put the kettle on... Again. Facebook says; Re-boiled water kills you.

Aside from a strong scientific argument as to why I avoid Facebook... Making the rounds is a warning to not "re-boil" water. Essentially, you put a kettle of water on to boil to make coffee or tea. You get distracted and forget about it for a while. Later, you turn the heat back on and boil it again and try to make your drink a second time... According to this tale, you've just set yourself up to drink a deadly toxic concoction of liquidy death. Yummers. The reasons given for this are that it -Chemically changes the water. (What? What does that even mean? How does it chemically alter the water?) -Concentrates existing diluted toxins into a less dilute solution. (The way I got it figured, you would have to reboil it a whole lotta times before that became harmful...) Maybe someone who is a better chemist than I am (I made something interesting with Sunlight dish detergent and liquid bleach once) could weigh in on if that makes any sense at all. To my mind though, it sounds like a load of bovine excretions. If there was a chemical change from evaporating water, our several billion year old Water Cycle would have some serious explainin' to do. Archived source: https://web.archive.org/web/20160808101451/http://www.spacetimeandtheuniverse.com:80/biophysics/8253-dont-put-kettle-again-facebook-says%3B-re-boiled-water-kills-you.html