A man with closed eyes walking into a skeletal death figure, a group of anxious undertakers run after them. Coloured etching by R. Newton, 1794, after himself.

Science fiction and laymen’s superstitions abound with the concept that the image of the killer is embedded in the retina of the victim. Thanatographia is the account of a person’s death experience and imago mortis is the hypothesis that the image imprinted on the retina after a violent death can remain there for a long time, almost as if the retina itself performed the task of the photosensitive emulsion of any photographic film or plate.

Alessandro Giuseppe Antonio Anastasio Volta

Early 18th to Late 19th Century Forensic Experiments

To investigate the origin of this possibility one should return to some scientific experiments of the 18th century in Bologna, focused on the relationship between electricity and vital functions.

Alessandro Giuseppe Antonio Anastasio Volta (1745 - 1827) was an Italian physicist, chemist, and a pioneer of electricity and power, who is credited as the inventor of the electric battery. Volta was embroiled in a dispute with contemporary Luigi Galvani (1737 - 1798) over the true origin of the movements of the frogs, used by Galvani in his experiments.

At the time in Bologna, between the two schools of thought, the theory advanced by Volta prevailed, who saw in the spasmodic movements of the frogs sacrificed on the altar of science, only the effect produced by the contact of two metals, copper and zinc, within the muscle structures of the poor frogs. In such conditions, in fact, a difference in potential is created, of a fraction of a volt, due to the bimetallic pair able to stimulate for a moment the muscular apparatus of the frogs and give the impression that they are almost resurrected.

Luigi Galvani (1737-1798)

In Bologna, Galvani's nephew, the physicist Giovanni Aldini (1762 - 1834), published his London study entitled: An account of the late improvements in Galvanism in which he describes his experiments with bimetallic arches, no longer intended to move the legs of innocent frogs, but the limbs of human corpses.

Giovanni Aldini often set up shows in which - through electricity - he induced spasmodic, perhaps gruesome, movements of facial muscles, and muscles of the limbs in human beings who had recently passed on.