As for what actually remains of the old traditions, [in Celtic Magic, St Andrews University] Ehrmantraut has, through textual scholarship and archaeology, attempted to piece together “the activities that regular people might have practised on a daily basis”. Celtic cultures passed their knowledge down orally. Written accounts of them tend to come from Roman enemies and Christian successors. But there was occasional contact with the Greek alphabet in Gaul, and the invention of later rudimentary scripts in Ireland. These are the records that allow Ehrmantraut to weave original curses or incantations into her lively account of the transmission of this knowledge.

There is no first-hand evidence, she writes, of people being burned in a wicker man — a large figure made of woven branches. Julius Caesar, whose writings provide the earliest surviving report of this, may even be drawing from a much earlier Greek philosopher whose own writings have since been lost.

The practices we do have evidence for tend to be cultural hybrids — especially in early Christian Ireland, where, Ehrmantraut shows, people might have combined a protection spell with a prayer to St Patrick for good measure. As for the remedy for worms: “The medical practitioner is to sing the following charm nine times in the afflicted person’s ear, followed by the Paternoster: ‘gonomil orgomil marbumil’. These words are slightly garbled Old Irish for ‘I wound the beast.’”

[In search of Albion — the folklore, myths and magic that built British culture]