Upon the Retina

A Mr. Warner, photographer, on reading an account of Emma Jackson in St. Giles's, addressed a letter to Detective Officer James F. Thompson, informing him that "if the eyes of a murdered person be photographed within a certain time after death, upon the retina will be found depicted the last thing that appeared before them, and that in the present case the features of the murderer would most probably be found thereon." The writer exemplified his statement by the fact of his having, four years ago, taken a negative of the eye of a calf a few hours after death, and, upon a microscopic examination of the same, found depicted thereon the lines of the pavement on the slaughterhouse floor. This negative is unfortunately broken, and the pieces lost.

The Cincinnati Lancet & Observer (1863)