Richet's Coinage and the Photographic Record

The term ectoplasm entered the language through Charles Richet, a French physiologist and eventual Nobel laureate in medicine, who coined it in 1894 during his investigations of the Italian medium Eusapia Palladino, building the word from Greek roots meaning "outside" and "something molded" to describe a substance he believed emerged from a medium's body and could take on a life or shape of its own. Richet did not himself claim the substance was spiritual in origin, treating it instead as an unexplained physiological phenomenon, but the term was quickly adopted throughout spiritualism to describe the visible material from which materialised spirit forms, faces, hands, or whole bodies, were said to be built during a séance.

German physician Baron Albert von Schrenck-Notzing produced the most extensive photographic record of the substance in the 1910s, particularly in his sittings with the French medium known as Eva C. (born Marthe Beraud), publishing dozens of images of pale, cloth-like material apparently emerging from her mouth or body under dim red séance lighting, images that circulated widely in the press and in Schrenck-Notzing's own books, and shaped the public image of ectoplasm for decades afterward.