The wax in a lava lamp used to contain carbon tetrachloride to help it sink in water, however carbon tet was banned in the U.S. in 1970 and the new compound has been kept a trade secret.
Hanson Gregory claimed to have invented the ring-shaped doughnut in 1847 aboard a lime-trading ship when he was 16 years old. He claimed to have punched a hole in the center of dough with the ship's tin pepper box. [Wikipedia]
