Ectoplasm- A supernatural vicious substance that is suppose to exude from the body of a medium during a spiritualistic trance and form the material for the manifestation of spirits.
Ectoplasm is a substance or spiritual energy “exteriorized” by physical mediums. Ectoplasm is said to be associated with the formation of spirits, and asserted to be an enabling factor in psychokinesis.
"Photo of a spirit medium with Ectoplasm. Thomas Glendenning Hamilton, "Mary M. with umbrella ectoplasm", 25 February Gelatin silver print" Hoax? Many ectoplasm photos were faked.
This is NOT "a card given to men to advertise houses of prostitution. " It was a Victorian custom to have a mourning photo taken with one's back to the camera.