I thought this was an amusing and interesting hoax that has been out there on the internet for some time. One of my students asked me if I thought DHMO should be banned. When I figured out she was talking about water I laughed! I found there to be a plethora of info on this subject on the web. I use this as an extra credit or absent assignment. It could be used with a sub, or as a filler on a day when you finish early. Enjoy!