Angelo Sala, a Venetian physician, first noted the natural blackening of silver nitrate when exposed to sunlight. A century later, silver salts were used to permanently blacken feathers and furs, and in 1727, Johann Heinrich Schulze of Magdeburg created photographic images of words by placing paper masks on the surface of a bottle containing chalk, aqua regia, and silver. However, despite the centuries-long use of the camera obscura among painters for the accurate depiction of landscapes, photography would not be invented until much later. Joseph Nicephore Niepce would use silver chloride for his original images, and Louis Daguerre would use silver plates sensitized with iodine vapor.
