In the mid-19th century, a movement was spreading, one in which people talked to the dead. The emergence of Spiritualism is traced to March 31, 1848 in Hydesville, New York, where sisters Kate and Margaret Fox claimed they’d made contact with a spirit, communicating through a series of taps. Soon public séances were attracting everyone from newspaper man Horace Greeley to Sojourner Truth, and table rapping, spirit photography, and mediums were part of a new, much more personal, connection with the afterlife.
There were plenty of skeptics who considered this to be all superstition and trickery. One was J. H. Brown, who decided to create a book of optical illusions to demonstrate how “ghosts” could be manifested through science. Elaborately titled Spectropia, or, surprising spectral illusions showing ghosts everywhere and of any colour, it was first published in 1864, with 16 plates each showing a different phantom. One featured a skeleton emerging from a cloud, another a witch flying on a broom. At the center of every illustration was a small asterisk that viewers are asked to stare at “for about a quarter of a minute,” before turning their eyes to the ceiling or a white sheet, where “the spectre will soon begin to make its appearance.”
If the conditions were right, what the reader saw was an afterimage, an optical experience in which the eye’s photoreceptors take in a stimulus and lose sensitivity. (Think of looking at a bright light or getting flashed in the face with a camera.) Further, it creates a negative of the viewed colors (so a red ghost would be green, a skeletal hand draped in orange would be blue). Brown explained his motive behind Spectropia in an introductory essay:
It is a curious fact that, in this age of scientific research, the absurd follies of Spiritualism should find an increase of supporters; but mental epidemics seem at certain season to affect our minds, and one of the oldest of these moral afflictions — witchcraft — is once more prevalent in this nineteenth century, under the contemptible forms of spirt-rapping and table-turning. … One thing we hope in some measure to further in the following pages, is the extinction of the superstitious belief that apparitions are actual spirits, by showing some of the many ways the eye may be deceived.
Brown followed his calling out of the “modern professor of these impostures” with a few pages of scientific explanation of the afterimage, and then came the ghosts. I happen to own a 19th-century edition of Spectropia, and have carefully opened its weathered green cover to experiment with seeing “ghosts everywhere.” While the details put into the illustrations — like the hairs on a witch’s nose or an angel’s halo of stars — don’t translate into the afterimage, they do suggest a haunting outline.
Brown’s book was popular and went through several editions, although it’s not clear if any Spiritualists lost their faith through his optical demonstration. A copy was owned by Lewis Carroll, who was a member of the Society for Psychical Research that delved into the paranormal, and pages even made it into Robert Mapplethorpe’s collection of mystical imagery. It’s also unique because the afterimage isn’t an effect that’s frequently used in art. Jasper Johns’s 1960s “Moratorium,” made to protest the Vietnam War, is an exception, its black, green, and orange colors suggesting camouflage and Agent Orange, with a dot in the middle like a bullet hole. Yet focus on it and look away, and the full red, white, and blue soars as a ghost of itself.
Below, you can try out some selections from Spectropia. A digitized version of an 1864 edition at Yale University is available at the Internet Archive, and the Library Company of Philadelphia recently created some delightful GIFs if you want to see them in motion.