Featured on PDR in the collection Decayed Daguerreotypes

A selection of images from the Library of Congress found via the always excellent Ptak Science Books blog. The daguerreotype, invented by Louis-Jacques-Mandé Daguerre in 1837, was the first commercially successful photographic process and was popular throughout the mid-19th century. Daguerreotype portraits were made by the model posing (often with head fixed in place with a clamp to keep it still the few minutes required) before an exposed light-sensitive silvered copper plate, which was then developed by mercury fumes and fixed with salts. This fixing however was far from permanent - like the people they captured the images too were subject to change and decay. They were extremely sensitive to scratches, dust, hair, etc, and particularly the rubbing of the glass cover if the glue…