The world is waiting who the cardinals will vote in as the new Pope at the Vatican. From this New York Times article, an interesting bit of trivia on how the black versus white smoke is generated to signal whether a Pope has been chosen:

The Vatican has given details of how the black smoke is generated, saying that, since 2005, a secondary device alongside the traditional ballot-burning stove generates colored smoke from different chemical compounds. Both devices feed into stovepipes that join up as a single smokestack on the Sistine Chapel roof.

For black smoke, the Vatican Information Service said, the compound blends potassium perchlorate, anthracene and sulfur. White smoke heralding a new pope comes from a mixture of potassium chlorate, lactose and rosin, “a natural amber resin obtained from conifers.”

Apparently before 2005, the black smoke was “obtained by using smoke black or pitch and the white smoke by using wet straw.”