Cyanide was a white powder which was poisonous to many species. It killed by inhibiting cellular respiration. Symptoms included headache, nausea and convulsions. Cyanide poisoning could be reversed with ethylenediaminetetraacetic acid. (TV: Rendition [+]Doris Egan, Torchwood series 4 (Starz, 2011).) Liquid cyanide could be identified by its blue colour and scent of almonds. (PROSE: The Baby Farmers [+]David Llewellyn, Consequences (2009).)
The Birastrop were not affected by it. (TV: The Brain of Morbius [+]Robin Bland, Doctor Who season 13 (BBC1, 1976).)
In 1899, Dr. Tiberius Finch used capsules filled with cyanide to compel his Blowfish creations. (PROSE: The Baby Farmers [+]David Llewellyn, Consequences (2009).)
In 1926, the Tenth Doctor was poisoned by Arnold Golightly with cyanide. Although by the time he noticed the symptoms of cyanide poisoning it would have been too late for a human to survive, the Doctor, having Gallifreyan physiology, neutralised the poison by drinking ginger beer, eating walnuts for protein and anchovies for salt, and then getting a shock - a kiss from Donna Noble. This allowed him to eject the cyanide from his body through his mouth in a gaseous form. (TV: The Unicorn and the Wasp [+]Gareth Roberts, Doctor Who series 4 (BBC One, 2008).)
UNIT used cyanide gas to kill a swarm of giant cave insects. (PROSE: Caverns of Horror [+]Doctor Who Annual 1971 (Doctor Who annual, 1970).)
In 1984, Lt. Doyle attempted to kill the Sixth Doctor by giving him cyanide-laced coffee. (AUDIO: The Reaping [+]Joseph Lidster, Main Range (Big Finish Productions, 2006).)
In the 1980s, Oscar Botcherby used cyanide to kill moths for his collection, saying it was quicker and kinder to them than other poisons. The Sixth Doctor used Oscar's cyanide to smother and kill Shockeye of the Quawncing Grig. (TV: The Two Doctors [+]Robert Holmes, Doctor Who season 22 (BBC1, 1985).)
The Fourth Doctor injected cyanide (in a gaseous form) into the laboratory of Mehendri Solon, killing him. Morbius survived as the body Solon had created for him included a set of lungs from a Birastrop. (TV: The Brain of Morbius [+]Robin Bland, Doctor Who season 13 (BBC1, 1976).)
The Fourth Doctor suggested using cyanide to kill the giant rats that inhabited the London sewers. (TV: The Talons of Weng-Chiang [+]Robert Holmes, Doctor Who season 14 (BBC1, 1977).)
When forced to create EDTA to cure arsenic poisoning, Gwen Cooper used cyanide in the antidote. (TV: Rendition [+]Doris Egan, Torchwood series 4 (Starz, 2011).)