Noun
A picture taken on a plate of prepared glass, in which the lights are represented in silver, and the shades are produced by a dark background visible through the unsilvered portions of the glass.
Source: Webster's dictionaryGittings (1968), 264 Ambrotype of Fanny Brawne taken circa 1850 (photograph on glass) On 3 April 1819, Brawne and her widowed mother moved into the other half of Dilke's Wentworth Place, and Keats and Brawne were able to see each other every day. Source: Internet
July–September * July 4 James Ambrose Cutting takes out the first of his three United States patents for improvements to the wet plate collodion process ( Ambrotype photography). Source: Internet