Xenobe Purvis grounds The Hounding in a real medical mystery from early modern England. In 1701, the physician Dr. John Freind (stylized as Dr. Friend in the novel) published a letter in the Philosophical Transactions of the Royal Society, a leading scientific journal, describing a strange case he had investigated in Oxfordshire. There, Freind documented a family in which several sisters were reportedly seized by violent convulsions that caused them to bark like dogs, an affliction that reportedly persisted for weeks and drew the attention of clergy, neighbors, and physicians alike. Freind approached the case with the empirical curiosity typical of Royal Society correspondents, yet his conclusions were shaped by the prevailing medical frameworks of his day. His account provides the novel’s foundational premise about five sisters in a rural English village whose bizarre affliction sparks fear and suspicion.

Central to Freind’s diagnosis, and to the world of the novel, is the early modern theory of animal spirits. When Dr. Friend examines the Mansfield sisters in Chapter 17, he attributes their fits to a “nervous disorder caused by erratic animal spirits” (155). To a modern reader, this may seem absurd, but it reflects mainstream medical thought at the time. Rooted in the work of the ancient Greek physician Galen and revived by 17th-century anatomists, the theory proposed that the nervous system functioned via a fine, vaporous substance produced in the brain.