ถ้อยคำอาบราคาดาบราabracadabra

Serenus Sammonicus, physician to the Roman emperor Caracalla, wrote in chapter 52 of the Liber Medicinalis that a sufferer from malaria should wear an amulet with Abracadabra written on it in the form of a triangle. He claimed the amulet makes lethal diseases go away. Other emperors who followed his medical teaching — Geta and Severus Alexander — may have used the formula too.

The form was understood to do the work. Written in the shrinking triangle, the word was taken to act like a funnel, driving the sickness out of the body. That is a claim about a shape, not about a language, which fits a word nobody could translate then either.

It was picked up by the Gnostics of the sect of Basilides, who used it invoking beneficent spirits against disease and misfortune, and it is found on Abraxas stones worn as amulets. From there its use spread past the Gnostics.

It kept turning up on parchment. A sixteenth-century Jewish codex from Italy, Ets ha-Da'at (The Tree of Knowledge), a collection of magical spells, carries it as an amulet described as a 'cure from heavens' for 'all sorts of fever[s]', consumption and fire.

It was also argued with, in print, for centuries. The Puritan minister Increase Mather dismissed the word as bereft of power. Daniel Defoe wrote dismissively about Londoners who posted it on their doorways to keep sickness out during the Great Plague of London.

By the early 1800s it had become an example of what magicians say, and that is where it stayed; today it is the tag line at the end of a trick. Aleister Crowley took it back the other way, adapting it into Abrahadabra in The Book of the Law, the central text of Thelema.

Inference — the arc is from a prescription written by a named imperial physician to a punchline, with the shape doing the work at one end and the sound doing it at the other. Very few objects in this atlas can be dated to a chapter number.