This 19th-Century ‘Toy Book’ Used Science to Prove That Ghosts Were Simply an Illusion

In 1864, a book called Spectropia set out to expose how the brain can trick people into believing they’ve seen a ghost. Across 27 pages, author J.H. Brown laid out how readers could summon spooky images by staring at one of the book’s 16 illustrations of “specters” and then immediately looking at a blank wall. The resulting optical illusion wasn’t a supernatural apparition: Instead, it was the product of a scientific phenomenon known as afterimages.

Brown wanted Spectropia to act as a bulwark against the rising tide of Spiritualism, a religious movement that suggested the living could commune with the dead, typically through mediums and séances. Brown’s background, including how he came to be so well versed in the science of the time, has been lost to history. But his writings make it clear that he was ardently anti-Spiritualist. As Brown argued in Spectropia:

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 seasons to affect our minds, and one of the oldest of these moral afflictions—witchcraft—is once more prevalent in this 19th century, under the contemptible forms of spirit-rapping and table-turning.

Despite Brown’s serious intentions, Spectropia’s publisher marketed the book as a fun parlor game, a way for folks to stave off boredom for an evening. “Ghosts everywhere,” one contemporary ad stated. The notice promised that buyers would conjure up “ghosts of all sizes, all styles, all colors, at 60-second notice.”

The “toy book,” as Spectropia was also described, proved popular, first in London and Sydney and then in the United States, where it sold for $1 (around $20 today). While one reviewer heralded the work as an “elegant volume [that] may familiarize even the thoughtless with optical laws, and thus abate the tendency to superstitious impressions,” Spectropia’s success as an anti-Spiritualist tool is difficult to measure. Indeed, another critic dismissed the publication as a “philosophical plaything intended to amuse children and youth.”

The science behind the “specters”

Brown implicitly acknowledged that many readers would open Spectropia and skip all text besides the directions for creating afterimages, as the illusions are now known. But for “those who may wish to know more,” he included a “brief and popular, as well as a scientific, description of the manner in which the specters are produced.”

In that section, says Tedi Asher, a neuroscientist at the Peabody Essex Museum in Massachusetts, Brown correctly described why, if a person stared at one of the book’s images under a strong light source for about 20 seconds and then gazed at a blank wall in a darkened room, a version of that image in inverted colors appeared.

Today, psychologists know that this phenomenon occurs because the color-sensing cells, or cones, in humans’ retinas decrease in sensitivity to a certain color after looking at an object of that hue for an extended period of time. Let’s say you stare at the fifth illustration in Spectropia—a wizened individual, colored entirely in red, with their arm ominously raised—for about half a minute. If you then look at a white wall, you’ll see a green version of the figure, which will start to break up before disappearing entirely.

This color change takes place because your retinas’ ability to see red is temporarily fatigued. Since white light contains all color wavelengths, you’ll still see the primary colors of blue and yellow, which, when mixed together, yield red’s complementary color, green. In addition to reversing the color of an image, afterimages can convince your brain that an object has changed in shape or size. All told, Brown argued in Spectropia, “There can be little doubt but that many of the reputed ghosts originate in this manner.”

The Colour After Image Illusion (best full screen)

Many of the 19th-century readers who enjoyed a fun night creating ghostly images with Spectropia undoubtedly also believed in supernatural spirits. “[Brown] is saying our minds and our eyes [can] play tricks on us, and this is a well-known scientific principle,” says Jim Steinmeyer, an illusion designer and historian. “[He’s asking], ‘Can’t I demonstrate to you that you can’t trust your senses?’ And overall, that somehow never works, because anyone who’s really convinced just says, ‘Well, it doesn’t make any difference [in what I believe].’”

Asher, who wrote an essay about Spectropia for a book accompanying one of the Peabody Essex’s current exhibitions, “Conjuring the Spirit World: Art, Magic and Mediums,” says that three processes shape people’s beliefs. Humans perceive something, attribute personal meaning to it and then act on it accordingly.

“People have real needs that drive the way they choose to understand the world and their experiences in it,” Asher explains. “Certain aspects of any visual input are going to be salient and stand out to a given individual for one reason or another. You connect those dots—literally or figuratively—to generate a particular need. It’s similar to how two dots and a half circle under them causes a smiley face, even without a bounded circle around it. It’s the way our brains take bits of information and weave together a narrative.”

The power of belief, whether in spirits, the afterlife or mediums, is likely why Spectropia did little to stave off the Spiritualism movement.

The “mental epidemic” of Spiritualism

Spectropia came out during the first wave of Spiritualism, which many trace to upstate New York in 1848. That year, a pair of young girls named Maggie and Kate Fox convinced the public that spirits communicated with them through mysterious rapping noises. Though the Fox sisters eventually admitted to faking the sounds with their knuckles, joints and toes, the movement they spawned quickly gained a fervent following.

In the U.S., Spiritualism remained influential into the 1860s, in part because the Civil War left many grieving over the loss of loved ones they couldn’t properly bury. The movement inspired other fraudsters to claim they could commune with unnatural forces, too: Siblings Ira Erastus Davenport and William Henry Harrison Davenport, for example, made a name for themselves stateside before traveling to England in September 1864, the same year that Spectropia arrived on bookshelves.

On September 28, the Davenport brothers held a séance at a private residence in London. The act found the pair tied up inside a large cabinet. Once the doors were closed, various musical instruments, including a guitar and a trumpet, started playing and banging against the cabinet’s walls. An assistant “quickly dashed to open the doors, catching the instruments almost airborne as the two brothers were revealed, sitting quietly and tied up tightly,” writes Steinmeyer in Hiding the Elephant: How Magicians Invented the Impossible and Learned to Disappear. Many of the spectators believed the Davenports were true mediums, but the press was far from convinced.

“These American brethren, we are informed, can keep up an excitement for several hours successively,” the Standard reported a few days after the séance. “It was all ‘spiritual,’ they say; but might we, under the circumstances, be permitted to suggest that it was all from beginning to end a piece of flagrant jugglery?”

Referencing an illusion popularly known as Pepper’s Ghost, in which performers create a transparent image of a person onstage by having them stand behind a pane of glass that is strategically angled and lit offstage, the Standard noted, “White ghosts are in fashion. We have seen them at the theaters. We know how they are made. Sorcery of that kind is, in our day, excusably popular.” The newspaper argued, however, that the Davenports’ “vulgar legerdemain,” or sleight of hand, represented “an intellectual poison and intoxication.”

Against this backdrop of skepticism versus passionate belief, Spectropia aimed to use science, delivered via the promise of conjuring up “weird and ghostly figures,” to explain how acts like the Davenports’ worked. Ironically, part of the appeal of Spiritualism was that it claimed to take a scientific approach to ghosts. George Schwartz, curator of “Conjuring the Spirit World,” says there were those like Brown, “who believed science could be used to show that there’s nothing to Spiritualism, [and] those who were actually using it to test mediums and ‘prove’ that they did have supernatural abilities that could be scientifically tested.”

The chemist William Crookes, for example, held so-called scientific séances in the mid-1870s. During these get-togethers, he asked well-known mediums like Florence Cook to grasp a device called a galvanometer. If the supposed clairvoyant took their hands off the apparatus’ two handles, the electric current running through it would break, and observers—sitting in the next room with a mere curtain separating them from the medium—would know via the device’s readings. Several participants passed the test by circumventing the current, most likely using a coil of wire to replace their body resistance so they could move freely in the room and make various items levitate or change location.

Armed with supposedly scientific proof that clairvoyants were real, Spiritualists were often reluctant to accept alternative explanations for mediums’ abilities, however thoroughly researched they might be.

Spectropia “bridged the connection between the scientific world and the supernatural early on,” blurring the line between fun novelty and anti-Spiritualist screed, Schwartz says. In that way, the book was similar to the perennially popular Ouija board, which to this day is advertised as a toy, though some still believe it has true mystical capabilities.

Ouija Board: The Mysterious Origins of a Cultural Obsession

Beginning in the late 1860s, a few decades before the Ouija board debuted, the planchette, a small, usually heart-shaped board that spirits purportedly moved when people lightly touched its surface, took the U.S. by storm. As Spectropia’s popularity petered out, planchettes appeared in homes across the nation, where holding an impromptu séance to summon a deceased loved one was a common way to spend an evening. Perhaps the playful ambiguity of how planchettes worked made them more appealing than a book that sought to provide a rational explanation for a seemingly otherworldly phenomenon.

In the words of England’s Birmingham Gazette, which reported on the Davenport brothers’ séances in October 1864, “When one delusion is laid bare, a large section of the public will run just as eagerly after another, and rather resent than approve any attempt to undeceive them.”