Oracles—those who speak from worlds unseen—have a long and colorful history. Since ancient times, many have believed oracles were portals through which the gods spoke directly to people, providing wise counsel or making prophesies. Explanations for these proclamations have puzzled investigators for many years. Now, evidence shows that at least some ancient oracles likely were under the influence of poisonous substances ranging from ethylene gas and oleander to mercury. Interesting findings!
The Oracle of Delphi
Priestess of Delphi (1891) by John Collier, showing the Pythia sitting on a tripod with vapor rising from a crack in the earth beneath her (Wikipedia)
The ancient Oracle of Delphi, the high priestess of the Temple of Apollo at Delphi in Greece, was famously known for prophecies reported by Aristotle, Diogenes, Euripides, Herodotus, Ovid, Plato, Sophocles, and many other ancient writers. People traveled to consult a priestess, known as Pythia, for at least 300 years, beginning around the end of the 7th century BCE and possibly a few hundred years earlier.
There are conflicting reports of how these oracles functioned, but one explanation is generally favored. A high priest at Delphi for several years, Plutarch, reported that the oracular powers were associated with spring water flowing under the temple. And from recent investigations, that appears to be the case. Beneath the temple, geologists have found numerous fractures and fissures in the bedrock, and they have traced two faults that cross directly beneath the temple site. The bedrock underlying the temple contains deposits of bitumen, a constituent of petroleum (also commonly known as asphalt or tar). The fissures in the rock could have allowed hydrocarbon gases such as ethylene or possibly methane emanating from below to waft upwards into the temple, possibly released by a series of earthquakes. Plutarch also noted that sweet fragrances filled the temple when the Pythia was present, which is consistent with the odor of ethylene gas. Further investigations of water samples from the Kerna spring above the temple contained evidence of a small amount of ethylene, which may have been higher in the past.
Reports from researchers including toxicologists and anesthesiologists confirm that inhaling a small amount of ethylene can cause trances and psychedelic experiences. Loss of inhibitions, physical detachment, and rapidly changing moods are other effects. In higher doses, agitation, delirium, and symptoms of thrashing wildly and groaning can occur—all characteristics that Plutarch described from witnessing the Pythia.
Another explanation for the Pythia’s behavior is oleander, as a priestess would chew the leaves of this plant and may have inhaled smoke rising through an opening in the temple floor from a brazier found in an underground chamber. Toxic substances in oleander can cause symptoms like those of epilepsy, hence the interpretation that the spirit of Apollo possessed the Pythia. Perhaps the combined effects of both ethylene and oleander contributed to the actions and proclamations of the oracle?
Elite Women in Ancient Valencia
Mercury sulfide, or cinnabar (HgS), is a mineral with an intense red color that many cultures have highly valued and widely traded for millennia. Typically found as a vein-filling mineral in association with volcanic rocks, it has been used in practices ranging from the , medicinal and metallurgical to symbolic and decorative (as the pigment vermillion). It also happens to be extremely toxic.
Cinnabar (USGS)
The Iberian Peninsula, now in modern Spain, has what is likely the largest mercury deposits and mines in the world at Almaden. At multiple sites in this region, archaeologists have found evidence of the use of cinnabar dating back to the Early Neolithic, the second half of the 6th millennium BCE. A particularly interesting case of mercury use is revealed in elite burials that were made over several hundred years and are almost 5000 years old.
At the archaeological mega-site of Valencina, in southwestern Spain, analysis of bone samples from 70 humans and 22 animals have revealed abnormally high mercury exposure. In one opulent and communal tomb, built into the side of a natural hill, a long passageway and a circular chamber at the end are lined with vertical slabs of slate coated with cinnabar. Inside the chamber, archaeologists found the remains of 20 people, with at least 15 women between the ages of 18 and 45. Several women were dressed in elaborate clothing covered with thousands of small beads carved from scallops and other marine shells, representing an enormous amount of labor. A rich assortment of grave goods, including amber beads, ivory combs, and fragments of gold foil, accompanied the individuals. The women’s bodies and the grave goods were all sprayed with cinnabar powder.
Located nearby was another exceptional burial of a single woman, nicknamed the Ivory Lady. She was interred at around the same time as the communal burials of women, between about 2900 and 2800 BCE, and also sprayed with cinnabar. Her grave contained an array of exotic items including a complete African elephant tusk placed at her head, a nearly complete ostrich eggshell from North Africa, and many items of ivory from both African and Asian elephants—outstanding burial wealth showing her prominence and connections over a large geographic area.
There is abundant evidence that the women in these elite burials, as well as others in the population, were exposed to large amounts of cinnabar in both life and death. One part mercury per million is considered dangerously elevated, and nine women had at least 100 parts per million, with the Ivory Lady in the most magnificent burial registering an astounding 185 parts per million. Repeated, intentional exposure to mercury, probably by inhaling it, likely resulted in these exceedingly high mercury levels. Notable effects on their nervous systems would surely have resulted, including convulsions, trance-like states, and eventually a loss of consciousness. Magical, ritual, or sacred experiences were likely associated with these altered states.
Experts have suggested that the mercury-affected women of ancient Valencina may have been similar to the acclaimed Oracles of Delphi thousands of years later.
The proclamations of oracles, and the substances that promoted their utterances, are lost in the dust of time. But the occasional new data discovered—from finding intersecting faults beneath the Temple of Apollo to the extremely high mercury content in the bones of women who had extravagant burials—provides insights into the mysteries of ancient oracles. Fascinating!
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Fascinating post, Roseanne. It seems that most of the oracles were women. Any hypothesis on why? Fighting the patriarchy perhaps?
Thanks, Steve! And yes, it does seem like most oracles were women – your suggestion about why this was the case sounds reasonable to me!