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.
