Oracle Inspired by Low-Oxygen Delirium

Oct. 9, 2006 —A lack of oxygen might have inspired the prophecies at the Temple of Apollo in the Greek town of Delphi, according to a new study.

Published in the current issue of the journal Geology, the research contradicts a previous study suggesting that the Delphic priestess, known as pythia, who issued the prophecies was high on ethylene gas rising from bedrock cracks at the intersection of two faults directly beneath the temple.

According to Giuseppe Etiope, a geologist at the National Institute of Geophysics and Volcanology in Rome, the pythia's altered state was likely due to methane-induced hypoxia — oxygen deprivation caused by methane gas leaking into the temple's small, non-aerated chamber.

Perched in the mountains of Phokis on the foothills of Mount Parnassos 100 miles northwest of Athens, the Delphi sanctuary was one of ancient Greece's most sacred sites from 700 B.C. until A.D. 381, when it was destroyed by the Romans.

The biographer Plutarch (A.D. 46-120), who served as a priest in the temple for many years, left a detailed account of how the oracle worked.

Prophecies were delivered by the pythia, a woman who held the position of oracle and would act as the sun god Apollo's mouthpiece. During her trance, she sat upon a tripod in the Adyton, a small underground chamber bathed in sweet vapors.

Various excavations failed to find any sign of gases emanating from the earth. But in the late 1990s, a U.S. team led by geologist Jelle De Boer of the Wesleyan University in Connecticut, found traces of methane, ethane and ethylene.

De Boer concluded that ethylene, a central nervous system stimulant that can produce euphoria and delirium, was a probably an essential agent in the pythia's consultation.

But the authors of the new study aren't so sure.

"We did discover signs of gas exhalation in Delphi, but the possibility of ethylene intoxication is very unlikely," Etiope told Discovery News.

Odorless and colorless, ethylene is generated by bacteria fermenting at low temperatures. According to the Italian team, this gas could not be produced in the deep carbonate rocks of Delphi — at least not in the amount necessary to induce neurotoxic effects such as trance and delirium.

Etiope and colleagues detected small amounts of carbon dioxide, ethane and methane in the limestone beneath the temple.

Etiope and colleagues concluded that if any gases had neurotoxic effects on the pythia, they were most likely carbon dioxide and methane, which together would have caused oxygen depletion.

Ronald Klusman, emeritus professor of chemistry and geochemistry at Colorado School of Mines, agreed that oxygen depletion could have caused unconsciousness and occasional deaths in Delphi.

"I do agree with Etiope's conclusions, but final conclusions require additional, more sensitive measurements of a wider range of hydrocarbons," Klusman told Discovery News.