Before transfiguration can take place, a person who is said to have psychic abilities that enable them to communicate with the spirit world, will go into an altered state of consciousness to makes it easier for the dead to communicate with the living. In some cases, they may be in such a deep state of trance that they appear to have fallen asleep.
If the transfiguration is successful, a veil of ectoplasm will appear on or just in front of the sitters face. This is moulded into the features of the spirit that is trying to communicate. Ectoplasm is a light coloured, glutinous substance that allegedly oozes from the medium's body and is then physically manipulated by the spirit. It's sensitive to light and so séances often take place in darkened rooms. Sometimes it may be barely visible to the naked eye but can be seen in photographs. At the end of the séance, the ectoplasm is said to return to the medium's body.
During transfiguration the face that materializes may appear to be almost translucent, or in extreme cases the medium's face might disappear altogether, replaced by the features of the spirit. The spirit may mouth words and in some cases may also manipulate the vocal chords of the medium and speak through them. It isn't just the face that can be affected by transfiguration. There are stories of other parts of the body taking the form of the spirit, making the sitter appear taller or shorter, or changing their hair and other physical features. If the dead person used to wear certain clothes or jewellery, these may materialize too.
There are cases where more than one face has appeared during a transfiguration séance. If there is a group of people present, many of them may claim to see a face or number of faces that they recognize as dead loved ones.
Transfiguration was popular during the Victorian period and the beginning of the 20th century, when interest in spiritualism was at its height. Many séances were held in the hope that the faces of dead loved ones would appear, especially during and after World War I. Sir Arthur Conan Doyle, famous for his Sherlock Holmes novels, was a great supporter of spiritualism, including transfiguration. He wrote books on the subject and was president of the College of Psychic Studies.
During the manifestations, the sitter usually sits within an enclosed area, called a cabinet. The cabinet is basically anything which allows a physical medium to sit away from the sitters. The cabinet also helps focus the energies and creates a type of battery from which the phenomena can be formed and energized.
Cabinets appeared during the heyday of Spiritualism and were used by mediums as part of the trappings of the physical séance. The "cabinets" as they were called were often either actual pieces of furniture, a curtained off corner of a room or even a doorway. They became the physical medium's work space and its purpose was to "attract and conserve spiritual forces". Paranormal researcher Hereward Carrington referred to a spirit cabinet as a "spiritual storage battery."