A publication of the Archaeological Institute of America
In ancient legends the combustible cloak was a weapon for exacting revenge.
Greek myths tell of clothes treated with secret substances that caused them to burst into flames. The hero Herakles and the Corinthian princess Glauke were supposedly burned to death by flaming garments, and elements of these myths were depicted on painted vases. Such fires are described in remarkably similar and graphic terms, suggesting that some real phenomenon inspired the legends. The clinging and corrosive nature of the flames and the fact that water could not extinguish them suggest that the secret substances may have been a napalm-like mixture of a petroleum derivative and a thickening agent. The use of similar flaming concoctions as weapons and magic tricks (pyr automaton, or self-lighting fire) is described by many ancient authors. The three key ingredients seem to have been petroleum, sulphur, and lime, all substances used in treating and dying cloth. If residues of these minerals were not fully washed from clothing before wearing, they could theoretically cause it to ignite. The tunica molesta, or flaming shirt, was commonly used to execute criminals in ancient Greece and Rome. These real phenomena must have inspired the myths of Herakles and Glauke.