The Probert Encyclopaedia of Science & Technology

DAGUERREOTYPE

Daguerreotype was the earliest process of photographic reproduction, and was so called after its inventor Louis Daguerre. A copper plate, polished and silvered, was sensitised by exposure to iodine vapour, and so coated with a fine layer of silver iodide. It was then exposed in a camera, like modern photographic film, but with a longer exposure time. It was afterwards removed and treated with mercury vapour, the mercury attaching itself to those areas which had been most exposed to light and settling there in a density proportionate to the strength of the light.
Research Daguerreotype