Project Gutenberg 2020-11-22 Public domain in the USA. 118 Brown, J. H. 13004459 Spectropia; or, Surprising Spectral Illusions Showing Ghosts Everywhere, and of Any Colour Wikipedia page about this book: https://en.wikipedia.org/wiki/Spectropia 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 a scientific publication written during the mid-19th century. The book explores optical illusions and the phenomenon of seeing "ghosts" through the manipulation of light and the physiology of the eye. It aims to demystify the occurrence of spectral visions, presenting a rational and scientific explanation for these optical experiences that were often attributed to the supernatural. The content of "Spectropia" is divided into directions for witnessing spectral illusions and descriptions of the underlying scientific principles. Brown provides detailed instructions for creating spectral images by gazing at particular illustrations, whereby observers can see complimentary color spectres upon turning their gaze to a blank surface. He explores how the human eye perceives colors and how the brain can be deceived, arguing that many ghosts perceived throughout history are merely the result of visual phenomena rather than actual apparitions. The book also critiques spiritualism and witchcraft trends of the time, aiming to educate readers about the scientific explanations for what they might perceive as supernatural events. (This is an automatically generated summary.) Reading ease score: 69.6 (8th & 9th grade). Neither easy nor difficult to read. en Ghosts Optical illusions GV Text Category: Science - Physics 58273 2025-07-25T09:23:40.463878 text/html 32456 2024-10-18T08:24:28 text/html 2681758 2025-07-25T09:23:44.883861 application/epub+zip 2677233 2025-07-25T09:23:42.073933 application/epub+zip 320162 2025-07-25T09:23:41.119864 application/epub+zip 3523215 2025-07-25T09:23:46.962836 application/x-mobipocket-ebook 3506292 2025-07-25T09:23:43.983847 application/x-mobipocket-ebook 1155982 2022-09-28T19:04:03.158529 application/x-mobipocket-ebook 39782 2025-07-25T09:23:40.174872 text/plain; charset=us-ascii 19753 2024-10-18T08:24:28 text/plain; charset=us-ascii 15904 2025-07-25T09:23:47.178835 application/rdf+xml 24326 2025-07-25T09:23:41.364877 image/jpeg 3363 2025-07-25T09:23:41.243878 image/jpeg 2166410 2025-07-25T09:23:40.542882 application/octet-stream application/zip Archives containing the RDF files for *all* our books can be downloaded at https://book.klll.cc/wiki/Gutenberg:Feeds#The_Complete_Project_Gutenberg_Catalog