Did The Earth’s Fumes Drive Pythian Prophecies?

“…neither her face nor hue went untransformed; Her breast heaved; Her wild heart grew large with passion. Taller to their eyes, sounding no longer mortal, she prophesied what was inspired from The God breathing near, uttering words not to be ignored,” wrote the poet Virgil, in his Aeneid describing how the Delphian priestess (Pythia) prophecised in a frenzied state of mind.

The high priestess at the Temple of Apollo at Delphi, located on the slopes of Mount Parnassus was widely credited for her prophecies inspired by the ancient Greek god of light, sun and music. The Oracle of Delphi was established in the 8th-Century B.C. and the last recorded response was given during 393 A.D. when the emperor Theodosius I ordered pagan temples to cease operation.

During this period the Delphic Oracle was the most prestigious and authoritative oracle among the Greeks. Everyone, from rich warlords to common people, would pay enough to get themselves a prophecy revealing the future and shaping their decisions and way of life based on the visions of the Pythia, which were delivered in a trance that most probably resulted from the inhaling of vapors rising from a chasm in the rock of the adyton (Greek for “inaccessible”).

Ancient Greek historian Plutarch (46-120 A.D.), who presided as high priest at Delphi for several years, observed in his documents that the Pythia’s oracular powers appeared to be associated with vapors from the Kerna spring waters that flowed under the temple. These observations of Plutarch have triggered the interest of scientists who conducted research over the years to determine the true origins of the Oracle’s inspiration that brought delirium to the local priestesses and made them talk in cryptic and rhymed language that were open to various interpretations.

According to the ancient legend, the hallucinative vapors were the breath of Python, the enemy of the Olympian deity Apollo, who slew her and remade her former home and the oracle his own. The body of the monster was buried deep under the Delphi Oracle, also considered the Center of the Earth, and with each of the breaths the Pythia would come one step closer to Apollo’s charisma of telling the future.

Excavations based on Plutarch’s remarks brought a team of French archaeologists directed by Théophile Homolle of the Collège de France to the site of Delphi in 1892. The French team focused their research on locating a hole in the ground, interpreting Plutarch’s observations to the letter, and so they found no fissure and no possible means for the production of fumes.

In 1904, Adolphe Paul Oppé published an influential article, which made three crucial claims: no chasm or vapor ever existed; no natural gas could create prophetic visions; and the recorded incidents of a priestess undergoing violent and often deadly reactions was inconsistent with the more customary reports. Oppé explained away all the ancient testimony as being reports of gullible travelers fooled by wily local guides who, Oppé believed, invented the details of a chasm and a vapor in the first place. In accordance with this definitive statement, scholars Frederick Poulson, E.R. Dodds, Joseph Fontenrose and Saul Levin all stated that there were no vapors and no chasm.

For the decades to follow, scientists and scholars believed the ancient descriptions of a sacred, inspiring soul to be fallacious. During 1950, French philhellene Pierre Amandry, who had worked at Delphi and later directed the French excavations there, concurred with Oppé’s pronouncements, claiming that gaseous emissions were not even possible in a volcanic zone such as Delphi. Neither Oppé nor Amandry were geologists, though, and no geologists had been involved in the debate until then.


Subsequent re-examination of the French excavations, however, has shown that this consensus may have been mistaken. Broad (2007) demonstrates that a French photograph of the excavated interior of the temple clearly depicts a springlike pool as well as a number of small vertical fissures, indicating numerous pathways by which vapors could enter the base of the temple.

During the 1980’s, the interdisciplinary team of geologist Jelle Zeilinga de Boer, archaeologist John R. Hale, forensic chemist Jeffrey P. Chanton and toxicologist Henry R. Spiller investigated the site at Delphi using this photograph and other sources as evidence, as part of a United Nations survey of all active faults in Greece.

De Boer saw evidence of a fault line in Delphi that lay under the ruined temple. During several expeditions, they discovered two major fault lines, one lying north-south, the Kerna fault, and the other lying east-west, the Delphic fault, which parallels the shore of the Corinthian Gulf. The rift of the Gulf of Corinth is one of the most geologically active sites on Earth; shifts there impose immense strains on nearby fault lines, such as those below Delphi.

The two faults cross one another, and they intersect right below where the adyton was probably located. (The actual, original oracle chamber had been destroyed by the moving faults, but there is strong structural evidence that indicates where it was most likely located.)

They scientists also found evidence for underground passages and chambers, and drains for spring water. Additionally, they discovered at the site formations of travertine, a form of calcite created when water flows through limestone and dissolves calcium carbonate, which is later redeposited. Further investigation revealed that deep beneath the Delphi region lies bituminous deposit, rich in hydrocarbons and full of pitch, that has a petrochemical content as high as 20%. Friction created by earthquakes heat the bituminous layers resulting in vaporization of the hydrocarbons which rise to the surface through small fissures in the rock.

De Boer’s research caused him to speculate ethylene as a gas known to possess this sweet odor. Spiller specified that inhalation of even a small amount of ethylene can cause both benign trances and euphoric frenzied states. Other effects include physical detachment, loss of inhibitions, the relieving of pain, and rapidly changing moods without dulling consciousness. He also noted that uncontrolled doses can cause confusion, agitation, delirium, and loss of muscle coordination.

Anesthesiologist Isabella Herb found that a dose of 20% ethylene gas administered to a subject was a threshold. A dosage higher than 20% caused unconsciousness. With less than 20% a trance was induced where the subject could sit up, hear questions and answer them logically, although the tone of their voice might be altered, their speech pattern could be changed, and they may have lost some awareness of their hands and feet, (with some it was possible to have poked a pin or pricked them with a knife and they would not feel it).

When patients were removed from the area where the gas accumulated they had no recollection of what had happened, or what they had said. With a dosage of more than 20% the patient lost control over the movement of their limbs and may thrash wildly, groaning in strange voices, losing balance and frequently repeatedly falling.