Wikipedia page about this book: https://en.wikipedia.org/wiki/Spectropia

Release date is 2020-11-22

Tim Lindell, Chuck Greif and the Online Distributed
Proofreading Team at https://www.pgdp.net (This file was
produced from images generously made available by The Internet
Archive/American Libraries.)

"Spectropia; or, Surprising Spectral Illusions" by J. H. Brown is an optical illusion book published in 1864. Disturbed by growing public belief in spiritualism, Brown created this illustrated work to offer scientific explanations for ghostly apparitions. The book features hand-colored plates that, when stared at and then looked away from, create spectral images floating on walls through the phenomenon of afterimage. Brown hoped to extinguish superstitious beliefs by showing how our senses can deceive us. (This is an automatically generated summary.)

Original publication data not identified