Pope Smoke

When the pope dies, and the cardinals have decided who will be the next pope, they will burn the ballets and mix them with a special chemical which will turn the smoke black. If they have not decided, they will burn the ballets as they are, and you will get white smoke.

http://runciblespork.blogspot.com/

http://news.bbc.co.uk/cbbcnews/hi/find_out/guides/2003/the_pope/newsid_3136000/3136568.stm