Arsenic

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Arsenic

Arsenic was an element that was used as a poison and a beauty product.

Arsenic was also, according to the Seventh Doctor, used as a preservative agent for taxidermy. (TV: Ghost Light)

In the 1800s, many people, such as Jack Harkness' Slovenian boyfriend, used arsenic for better skin. Jack talked about this when he was poisoned with arsenic by CIA agent Lyn Peterfield. (TV: Rendition)