Mina Crandon was a famous psychic medium also known as Margery. Through trance, she would manifest a substance known as "ectoplasm" from her body.
Below are some images of her work:
The ectoplasm was described by investigators as being gauze-like, wet cloth. Was it real? Despite her popularity as a medium, it would seem the "emanations of spirit" were faked. In 1925, Harvard scholars who investigated her concluded her to be a fraud.
For more about this topic, see: Mediums & Ectoplasm