Black and White Smoke

Sorry this week's experiment is late.  I got caught up in answering a question from MSNBC's Countdown program.  It turned out to be interesting enough for me to put the planned experiment for this week back in the file and write a new one.

The question was about the problems that the Vatican has been having with smoke.  At each vote, if there is no new pope, they are supposed to send black smoke up the chimney.  When a new pope is elected, they send up white smoke.  In the past, they have had problems with the smoke color.  If things don't burn properly, they can get gray smoke, which confuses everyone.