On the afternoon of 21 March 1815 Orlibar Turner and his family sat down to a meal of rump steak, potatoes and dumplings prepared by their young cook Elizabeth (or Eliza) Fenning. Shortly afterwards, the family was taken violently ill with stomach pains and vomiting. Next morning a local surgeon, urgently summoned to the Turners' house in London's Chancery Lane, identified arsenic in the dough that had been used to make the dumplings. Eliza was...