The Invisible Man

The Invisible Man is a 1897 science fiction novel, originally serialized in Pearson's Magazine. The Invisible Man of the title is "Griffin", a scientist who theorizes that if a person's refractive index is changed to exactly that of air and his body does not absorb or reflect light, then he will not be visible. He successfully carries out this procedure on himself, but cannot become visible again, becoming mentally unstable as a result.