ergotism

They can produce vasoconstriction, hallucinations, convulsions, and, at high doses, gangrene and death.

Ergot poisoning, known historically as Saint Anthony’s Fire, was a significant public health problem in medieval Europe, where contaminated grain could affect entire communities.

The connection between ergot alkaloids and LSD is direct.

Albert Hofmann, the Swiss chemist who first synthesized LSD in nineteen thirty-eight, derived it from ergotamine.

People described a horrible burning sensation in the limbs before they died, which is where the name came from.

They called it Holy Fire, and later St Anthony's Fire after the order of monks who ran hospitals for sufferers.

And here is the accidental genius of those hospitals.

The monks did not know what Ergot was.