Dr. Jeckyll and Mr. Hyde, a psychedelic tale

A new BBC documentary posits that Robert Louis Stevenson's "Dr. Jekyll and Mr. Hyde" was inspired by the writer's own drug-induced hallucinations. At the time he wrote the book, Stevenson's tuberculosis was being treated with a derivative of ergot, a hallucinogenic fungus. Evidence comes from a letter uncovered in Yale University's Stevenson archive:

In the letter, dated "end of August, early September 1885", Stevenson's wife wrote to William Henley, her husband's friend and literary agent: "Louis's mad behaviour . . . I think it must be the ergotine that affects his brain at such time.

"He is quite rational now, I am thankful to say, but he has just giving up insisting that he should be lifted into bed in a kneeling position, his face to the pillow."