Ergot
Ergot, which is caused by the fungus Claviceps purpurea, is a plant disease that affects cereal crops and grasseses such as rye, triticale, wheat and barley. It does not often affect oats.The disease causes a reduction in the yield and quality of grain and hay produced, and if infected grain or hay is fed to livestock it causes a disease called Ergotism.
Many ergot alkaloids, such as ergine, ergonovine and lysergic acid hydroxyethylamide have a poisonous hallucinogenic effect on the central nervous system, as they heavily interfere with neurotransmitter function.
Among those who studied ergot and its derivatives was Albert Hofmann whose experiments led to the discovery of LSD, an ergot derivative that strongly interferes with the neurotransmitter Serotonin.
The disease cycle of the ergot fungus was first described in the 1800s, but the connection with ergot and epidemics among people and animals was known several hundred years before that.
Human poisoning due to the consumption of rye bread made from ergot infected grain was common in Europe in the Middle Ages.
It has also been posited—though speculatively—that the Salem Witch Trials were initiated by young women who had consumed ergot-tainted rye.
The beverage consumed by participants in the ancient Greek mystery of Eleusinian mysteries might have been based on hallucinogens from ergot.
Some passages in the Bible may be interpreted to refer to ergot or ergotism, such as e.g. John 4:31-32 (one of the effects of ergot alkaloids is to suppress immediate hunger). Other passages report Jesus and his disciples walking in fields collecting heads of grain (Matthew 12:1, Mark 2:23, Luke 6:1). A possible interpretation of Mark 9:43 equates the reference to "hell fire" with St. Anthony's fire, although other interpretations considering the context of Mark 9:38-48 are more common.History