fire [OE] In ancient and medieval thought fire was seen, along with water, air, and earth, as one of the four elements. The word goes back to an ancient root that also gave us the Greek word for fire, pur, the source of pyre [M17th] and pyromaniac [M19th]. The phrase fire and brimstone [OE] is a traditional description of the torments of hell. In the biblical book of Revelation there is a reference to ‘a lake of fire burning with brimstone’. Brimstone [OE] is an old word for sulphur, and literally means ‘burning stone’. A fire-and-brimstone sermon is one that gives vivid warning of the dangers of going to hell if you misbehave. To set the world on fire [M17th] is to do something remarkable. An alternative British version was to set the Thames on fire [E19th], and a Scottish one is set the heather on fire [E19th]. Whichever version is used, it tends to be with a negative implication. In Anthony Trollope’s novel The Eustace Diamonds (1873) Lady Glencora is clear about the limitations of ‘poor Lord Fawn’ who ‘will never set the Thames on fire’.