Daguerreotype

First successful form of photography, named for Louis-Jacques-Mandé Daguerre of France, who invented the technique in collaboration with Joseph-Nicéphore Niepce in the 1830s. Daguerre and Niepce found that if a copper plate coated with silver iodide was exposed to light in a camera, then fumed with mercury vapour and fixed (made permanent) by a solution of common salt,