From 1848 to 1858, Dr. Hugh Welch Diamond was the Resident Superintendent of the Female Department at the Surrey County Lunatic Asylum in England. During this time, he also photographed the mentally ill patients, believing the images could be used in diagnosing and treating them.
He was a supporter of the pseudo-science of physiognomy, in which the face was thought to mirror the soul.
In a 1856 paper titled On the Application of Photography to the Physiognomy and Mental Phenomena of Insanity, this was written:
The Photographer catches in a moment the permanent cloud, or the passing storm or sunshine of the soul and thus enables the Metaphysician to witness and trace out the visible and the invisible in one important branch of his researches into the Philosophy of the human mind.
To see the haunting photographs, scroll through the slideshow above.