Entity
Vulcan
The Roman god of fire and the forge, identified with the Greek Hephaestus — the lame divine smith, and a stock name in alchemy for the working fire.
Vulcan was the Roman god of fire and the forge — destructive fire as much as useful fire, the heat that levels a city as well as the heat that works metal. The Romans set his chief festival, the Vulcanalia, in late August, when the harvest was in and the danger of fire at its height; they kept his principal shrine, the Volcanal, on the edge of the Forum, and built temples to him outside the walls, as if to keep the dangerous thing at arm’s length. He was an old Italian deity, his cult attested early in Roman religion, and his name was read into other words for burning long after.
When Rome absorbed Greek mythology, Vulcan was identified with Hephaestus, and the Greek god’s stories came with the name. Hephaestus was the divine craftsman — maker of the gods’ armor and palaces, of Achilles’ shield, of the thunderbolts Zeus throws — and he was lame, cast out of heaven in one telling by Zeus, in another by his mother Hera, and limping ever after. The Greeks made his workshop a volcano, beneath Lemnos or beneath Etna, where he labored with the one-eyed Cyclopes at the forge. That picture migrated wholesale to Vulcan, so that the later literary god is largely Hephaestus under a Latin name, while the older Roman deity beneath him is harder to recover.
The smith of the gods had a long afterlife in the language of alchemy. Alchemical and Hermetic writers, who routinely spoke of their materials and operations through the names of planets and gods, used “Vulcan” as a cover-name for fire — sometimes the ordinary fire of the furnace, sometimes an inward or “secret” fire held to act within the matter itself. In this usage the god’s mythic office, the working of crude metal into something finer by heat, reads almost as a parable of the alchemical opus, and writers exploited the parallel without much consistency from one author to the next. The name was a tool, not a doctrine; what a given text means by Vulcan has to be read out of that text.
The figure sits, then, at three removes from itself. There is the archaic Italian fire-god of the cult calendar, recoverable mainly through Roman religious practice; the Greek master-smith laid over him by literary identification; and the alchemists’ Vulcan, a name borrowed for the agent of transformation. The same word holds all three, and they do not quite reduce to one.