Case file · Witch trials
The Calabar ordeal bean reaches medicine
In Old Calabar, people accused of witchcraft were made to drink an extract of the esere bean: those who vomited were innocent, those who died guilty. In 1855 the Edinburgh toxicologist Robert Christison tested it on himself and nearly died.
1855 CE · 4.95, 8.32 · status: official
The account
Scottish missionaries had sent beans home. Thomas Fraser isolated its alkaloid, physostigmine, which became a drug for glaucoma and for reversing poisoning. Colonial authorities later banned the ordeal.
The sceptical view
The 'verdict' depended on dose and on how fast the drink was taken: a large dose swallowed quickly tends to be vomited.