Sulphur
From Tardis Wiki, the free Doctor Who reference
Sulphur was an element.
In 1666, a number of villagers were burning sulphur in a forest where the Doctor's TARDIS landed. (TV: The Visitation)
The planet of the Gonds had an atmosphere that was high in both sulphur and ozone. (TV: The Krotons)
The Eighth Doctor used a sulphur-match to start a fire on the House of Zarn. (PROSE: The Eight Doctors)
In 2003, Becky Lee Kowalczyck discovered sulphur deposits in the alley where the Eighth Doctor and Alistair Gordon Lethbridge-Stewart had been attacked by demons the previous night. (AUDIO: Minuet in Hell)
