The famed Oracle of Delphi on the slopes of Mt. Parnassos in Greece made known the will of the gods to rulers, philosophers, generals, politicians, and anyone else of reasonably high status who was anxious to hear a favorable word from the gods. For centuries, the Temple of Apollo at Delphi in central Greece contained the most prestigious oracle in the Graeco-Roman world, a favorite of public officials and individuals alike. At various times throughout its long history, the oracle was said to relay prophetic messages and words of counsel from Python, the wise serpent son of the Mother-goddess Delphyne or from the Moon-goddess Artemis through their priestess daughters, the Pythonesses or Pythia. Then, according to myth, the god Apollo murdered Delphyne and claimed the shrine and the Pythia for himself, imprisoning the serpent seer in the recesses of a cave beneath the temple. The name of Delphi means "womb," and suggests the journey that the seekers of prophetic knowledge had to take as they entered the cave of the Pythoness and descended deeper into the mystical recesses of the oracle, deeper into the womb of Mother Earth.
The Pythia would await the seekers while seated upon a three-legged seat, or tripod, and it was from such a perch that she would issue her prophetic utterances. The many tripods scattered throughout the cave were, in essence, individual altars for her sister priestesses, the three legs symbolizing the connection between them and the triadic spirit of prophecy.
In the summer of 2001, Jelle de Boer of Wesleyan University in Connecticut and coworkers discovered a previously unknown geological fault that passes through the sanctuary of the Temple of Apollo. Such a crossing makes the bitumen-rich limestone found there much more permeable to gases and groundwater. The researchers went on to speculate that seismic activity on the faults could have heated such deposits, releasing light hydrocarbon gases, such as ethylene, a sweet-smelling gas that was once used in certain medical procedures as an anesthetic. Although fatal if inhaled in large quantities for too long a period of time, in small doses ethylene stimulates the central nervous system and produces a sensation of euphoria and a floating feeling conducive to an oracle's visions.