"W. D. Porter, in the New York Herald, points out a new way to discover murderers. He says: ‘The following method will, in many cases, detect the perpetrators of a murder: It is well known that all objects are actually painted or impressed upon the retina of the eye. - Should a person die a violent death, the object before the eye at the time remains impressed on the retina. If the covering of the eye is scraped down thin, and a powerful magnifying glass applied, his image will be distinctly seen. This was the first discovery of the daguerreotype. Any scientific physician can do this.’"
~From Galveston Weekly News (Galveston, Tex.), Tuesday, August 12, 1856