On 15 August 1951, the bread in Pont-Saint-Esprit began to drive the town insane. People in the small town on the Rhône hallucinated that snakes were crawling under their skin and that they were being chased by fire. One man tried to fly from a window, sure his head had turned to molten lead. Seven died. Around two hundred and fifty fell ill, and roughly fifty were taken to asylums. Seventy years later, nobody agrees what was in the loaf.
The first and oldest suspect was ergot, a fungus that grows on rye. It is a reasonable suspect, because ergot has done this before, for real and on a vast scale. It is also the single most over-used explanation in the history of strange events. When a village went mad, when girls had fits in a Puritan courtroom, when crowds danced themselves to ruin, someone eventually said: the bread. Sometimes the bread really was the culprit. Far more often, it was a guess that hardened into a fact. Telling the two apart is the hard part.
The Disease That Was Real
Ergot is a fungus, Claviceps purpurea, that infects rye and a few related grasses. Instead of a grain, the plant grows a hard, dark body called a sclerotium, a curved horn packed with potent alkaloids. Rye is unusually open to it, and cool, wet summers let the fungus spread, which is why the rye belts of medieval Europe, eating dark bread through long damp seasons, suffered the most.
Eat enough of it and you get ergotism, and the disease comes in two faces. The first is gangrenous. The alkaloids clamp down on the small blood vessels of the hands and feet so hard that the tissue starves and dies. Fingers and toes burn with a deep pain, then blacken and mummify, and in bad cases drop off. The second face is convulsive: seizures and twisting spasms, with a sensation of insects crawling under the skin and, in the worst cases, hallucinations. Which face appeared seems to have varied by region, with the gangrenous form common in France and the convulsive form common in Germany.
The chemistry behind the two faces is not as tidy as it is often drawn. The blackened limbs come from the ergotamine class of alkaloids and their grip on the blood vessels, and that part is firm. The visions are usually pinned on the lysergic-acid family of ergot compounds, the close chemical relatives of LSD, though the literature does not give a clean one-molecule-one-symptom map. The neat split between a poison that rots and a poison that maddens is a useful summary, not a settled fact.
Saint Anthony’s Fire
The Middle Ages knew nothing of a fungus, only of the fire. The gangrenous form earned the names “holy fire” and “infernal fire” for the burning that came before the blackening, and across much of Europe it was called Saint Anthony’s Fire. The name came from the order that took the sufferers in.
Around 1095, in the Dauphiné region of France, a nobleman remembered as Gaston de Valloire founded a hospital brotherhood in thanks for his son’s recovery from the holy fire, a cure he credited to the relics of Saint Anthony the Great, the desert hermit of early Christian legend. Pope Urban II confirmed the order the same year. The Hospital Brothers of Saint Anthony grew until, by the fifteenth century, they ran something like three hundred and seventy hospitals from Spain to Germany, an early hospital network built around one disease.
The patients often got better at the Antonine hospitals, and the monks could fairly claim a miracle. The likely reason is plainer. The hospitals fed their patients bread made from clean wheat instead of the contaminated rye back home, and the journey itself separated them from the poisoned local supply. Nobody understood the mechanism. The link between the fire and the fungus was only made centuries later.
The worst numbers, though, are chronicle numbers. The standard account names a first great outbreak in Aquitaine around 944, with a traditional toll of some twenty thousand dead, and another a few decades on said to have killed forty thousand. Those figures come from medieval chroniclers, not from anything a modern demographer could check, and the dates shift between 944 and 994 depending on the source. What is solid is that the disease was real and recurrent, and that it killed on the scale of an epidemic. Ergot did not vanish with the Middle Ages either. As late as 1926, an outbreak in the Soviet Union sickened around twelve thousand people.
The Fungus Blamed for Salem
In April 1976, the journal Science published a paper by a graduate student named Linnda Caporael with a title that did half the work: “Ergotism: The Satan Loosed in Salem?” Caporael noticed that the symptoms of the afflicted girls of Salem in 1692, the convulsions, the sensation of being pinched and pricked, the crawling skin, the visions, lined up with convulsive ergotism. She built a circumstantial case around it. The 1691 growing season had been warm and wet, rye was the staple grain, and the children who fell ill clustered on the farming side of the village where the rye grew.
It is a seductive argument, and it spread far beyond the journal. It also did not survive the year. That December, the same journal ran a rebuttal by the psychologist Nicholas Spanos and Jack Gottlieb, who took the ergot theory apart on its own evidence. Convulsive ergotism is a dietary disease, so whole households eating the same bread should sicken together, yet in Salem only particular people were afflicted while others at the same table stayed well. There was no gangrene, anywhere. And the fits did not behave like poisoning. They stopped the instant an accused witch touched the girl, they were triggered by the sight of the accused in court, and over the months the afflicted learned to copy one another. Poison does not read the room. The accusations then spread to a dozen surrounding towns, with no one proposing that ergotised rye had spread to all of them at once. Spanos and Gottlieb concluded that the evidence did not support the ergot hypothesis at all.
Most historians of Salem agree with them. The theory is taught and repeated because it is tidy and physical and lets a terrible episode resolve into a moldy loaf, but the people who study the trials closely treat it as popular rather than proven. That gap, between what is satisfying and what the records support, is the whole problem.
Did Ergot Make Them Dance?
In July 1518, in Strasbourg, a woman stepped into the street and began to dance, and could not stop. Within a week dozens had joined her, and over the following weeks the chronicles count the dancers in the hundreds. The city authorities, on the theory that the afflicted had to dance the sickness out, first built stages and hired musicians, then thought better of it and sent the sufferers to a shrine of Saint Vitus. The dancing plague of 1518 is the best-documented of the medieval dancing manias, and ergot is the explanation people reach for first.
It does not hold up well. The objection is mechanical. Convulsive ergotism produces jerking seizures and rigid, painful spasms, not the sustained, days-long dancing the sources describe, and the vasoconstriction that defines the poison would leave a victim barely able to stand, let alone dance for a week. No one reported the blackened limbs that ergot leaves. And the outbreaks of dancing mania clustered along the Rhine and the Moselle across regions with different crops and climates, which a contaminated-rye theory cannot explain. The historian John Waller, who wrote the standard book on 1518, reads it instead as mass psychogenic illness: a population worn down by famine and disease, primed by a real regional belief that Saint Vitus could strike people with compulsive dancing. On his reading the strain did the rest and tipped a worn population into a shared involuntary trance. Even the famous death toll, fifteen a day at the peak, turns out to rest on later retellings rather than the contemporary city records, which mention no deaths at all.
The same shape appears further south, in the tarantism of Apulia, where people said to be bitten by a tarantula danced the pizzica for days to sweat the venom out. There the rival explanation was a spider rather than a fungus, and it fares no better, since the local spiders cannot produce the symptoms. The anthropologist Ernesto de Martino, who studied the surviving rite in the 1950s, read it as a structured ritual in which the bite gave a name to private distress and the dance gave it a release. Two famous outbreaks of involuntary dancing, two physical culprits proposed, and in both the explanation that has held up best is about minds and meaning rather than toxins. Ergot is not even a contender for tarantism. It only looks like one for Strasbourg because the fungus is the reflex answer.
The Kykeon Question
The most ambitious claim sends ergot back to the founding mystery cult of the Greek world. For nearly two thousand years, initiates at Eleusis drank a barley preparation called the kykeon and underwent a vision so guarded that almost nothing about it survives. In 1978, three figures proposed that the secret was a drug. The book was The Road to Eleusis, and its authors were the ethnomycologist R. Gordon Wasson, the classicist Carl Ruck, and the chemist Albert Hofmann. Their argument was that the kykeon contained a psychoactive ergot preparation, and that the visions of Eleusis were, in part, pharmacology.
The hypothesis is bold, and it is not accepted by most classicists. The central problem is the same poison that runs through this whole story. Untreated ergot does not give visions, it gives ergotism, so the question is how Greek priests could have isolated a safe, reliable, mind-altering dose without poisoning the initiates by the thousand, year after year. The authors proposed that the water-soluble alkaloids could be separated from the toxic ones, which is arguable in a laboratory and undemonstrated in a temple. There is a real and tantalising find at Mas Castellar in Spain, a sanctuary of Demeter where ergot was recovered from a drinking vessel and from a man’s teeth, which shows the fungus was consumed in a ritual setting. It does not show that Eleusis brewed a working psychedelic. The kykeon theory remains a hypothesis worth holding in mind, not a solved case, and the most honest thing to say is that the secret of Eleusis is still secret.
From Cursed Bread to the Delivery Room
There is a reason Albert Hofmann turns up in a Greek mystery cult, and it closes the circle back to Pont-Saint-Esprit. In November 1938, working at the Sandoz laboratories in Basel on the medical potential of ergot, Hofmann synthesised the twenty-fifth compound in a series of lysergic-acid derivatives and shelved it. Five years later, in April 1943, he came back to it, absorbed a trace by accident, and discovered what it did. Three days after that he swallowed a deliberate dose and rode his bicycle home through a transfigured Basel. LSD, the molecule that would define a decade, came out of the same fungus that blackened medieval limbs.
That is the strangest fact about ergot. The poison and the medicine are one substance. The vasoconstriction that killed by gangrene is the same action that makes ergotamine work against migraine and makes ergometrine, still in use, clamp a bleeding uterus shut after childbirth. The dopamine-acting ergot derivatives have been used against Parkinson’s disease. The same chemistry took a peasant’s foot to Saint Anthony’s Fire and stops a mother’s bleeding in a modern delivery room. It is only aimed in opposite directions.
Which brings the cursed bread of Pont-Saint-Esprit back into focus, and refuses to resolve it. Ergotism was the first diagnosis, reported in a British medical journal within weeks, and it remains the most widely accepted. Others have argued for a mercury fungicide on the seed grain. The historian Steven Kaplan, who wrote a whole book on the case, suspected a problem in the flour itself and concluded the cause was never settled. And a journalist later claimed the CIA had dosed the town with LSD, a story historians reject, partly because the residents fell ill a day and a half after eating, while LSD acts within hours. Pont-Saint-Esprit is still arguing.
The Reflex Answer
Ergot is a genuine horror with a body count to match, and it is also a magnet for the unexplained, and those two facts pull against each other. Saint Anthony’s Fire happened, in numbers, for centuries. The medicine in your nearest hospital came out of the same sclerotium. But the moment a strange event has no obvious cause, the fungus is offered up as the answer, and it fits Salem and Strasbourg far less well than its reputation suggests. The honest line runs between the epidemics we can document and the ones we have quietly retrofitted, and a great deal of what gets blamed on bad bread sits on the wrong side of it. The disease is not a mystery. The eagerness to find it everywhere is.
Related Articles
- The Dancing Plague of 1518, the Strasbourg outbreak the ergot theory keeps trying to claim, and the famine-and-belief reading that fits it better.
- Tarantism: Dance, Desire, Delirium, the southern Italian dancing rite, where a spider stands in for the fungus and the real story is about distress and release.
- The Eleusinian Mysteries, what we do and do not know about the kykeon and the vision it carried.
- Henbane: The Herb That Made Witches Fly, another plant whose chemistry sat behind centuries of accusation and altered states.
Sources
- Caporael, Linnda R. ‘Ergotism: The Satan Loosed in Salem?’ Science, vol. 192, no. 4234, 2 April 1976, pp. 21–26. DOI 10.1126/science.769159. https://www.science.org/doi/10.1126/science.769159
- Spanos, Nicholas P., and Jack Gottlieb. ‘Ergotism and the Salem Village Witch Trials.’ Science, vol. 194, no. 4272, 24 December 1976, pp. 1390–1394. DOI 10.1126/science.795029. https://pubmed.ncbi.nlm.nih.gov/795029/
- Schiff, Paul L. ‘Ergot and Its Alkaloids.’ American Journal of Pharmaceutical Education, vol. 70, no. 5, 2006 (the two forms of ergotism, the alkaloids, and their medicine). https://pmc.ncbi.nlm.nih.gov/articles/PMC1637017/
- Waller, John. A Time to Dance, a Time to Die: The Extraordinary Story of the Dancing Plague of 1518. Cambridge: Icon Books, 2008.
- De Martino, Ernesto. La terra del rimorso (The Land of Remorse). Milan: Il Saggiatore, 1961; English trans. Dorothy Louise Zinn, London: Free Association Books, 2005.
- Wasson, R. Gordon, Albert Hofmann, and Carl A. P. Ruck. The Road to Eleusis: Unveiling the Secret of the Mysteries. New York: Harcourt Brace Jovanovich, 1978.
- Hofmann, Albert. LSD: My Problem Child (LSD – Mein Sorgenkind). New York: McGraw-Hill, 1980 (the 1938 synthesis and the 1943 discovery).
- Kaplan, Steven L. Le Pain Maudit: Retour sur la France des années oubliées, 1945–1958. Paris: Fayard, 2008 (the disputed cause of the Pont-Saint-Esprit poisoning).
- ‘Hospital Brothers of Saint Anthony’ (the Antonine order, founded c. 1095 at Saint-Antoine-l’Abbaye). https://en.wikipedia.org/wiki/Hospital_Brothers_of_Saint_Anthony
- Salem Witch Museum. ‘Debunking the Moldy Bread Theory,’ 2023 (on the scholarly rejection of the Salem ergot hypothesis). https://salemwitchmuseum.com/2023/05/17/debunking-the-moldy-bread-theory/
