ectoplasma

Ectoplasma (also spelled ectoplasm) is a term used in spiritualism to describe a substance said to emanate from a living person, usually a medium, during séances. Reported as a pale, gelatinous, or filmy mass, it was claimed to be a materialization representing spirits or other entities. The word derives from Greek elements meaning "outer" and "formed." The concept gained popularity in the late 19th and early 20th centuries.

Mediums were said to produce ectoplasmic forms that could be seen, touched, or manipulated. Descriptions ranged from wispy sheets and membranes to tangible shapes such as faces, hands, or whole figures. In many accounts, ectoplasma was observed near or at the mouth, nose, hands, or other body parts, or as a veil or cloth that collapsed after a séance.

Skeptics and scientists later investigated such phenomena and often demonstrated fraud through stage magic or misperception. Numerous cases were exposed as misrepresentation, hoax, or the use of hidden props and devices. As a result, ectoplasma is generally regarded by mainstream science as unsubstantiated, though it has persisted in popular culture and in some parapsychological writings.

In biology, the term ectoplasm (sometimes called ectoplasm or ectoplasma in older texts) also refers to the gel-like outer portion of the cytoplasm of certain cells. This scientific sense is unrelated to paranormal claims, despite sharing a name. The concept remains of historical interest as part of the history of spiritualism and paranormal research.