The first practicable dry-plate process was devised by Richard Leach Maddox. Details published in 1871 described how an emulsion of silver bromide in gelatin, coated on to a glass plate and dried, remained light sensitive for a prolonged period. Although plates based on Maddox's formula were sold in London by John Burgess in 1873, it was only after improvements by Richard Kennett in 1874 and Charles Bennett in 1878 that fully satisfactory dry plates were manufactured and mass marketed. The new plates were widely adopted and within a few years dry emulsions had completely revolutionized photographic practice. More convenient to use and with greater sensitivity than wet- collodion plates, shorter exposures led to the introduction of hand cameras; dry emulsions made roll-film possible. Modern sensitized materials continue to be based on gelatin silver halide emulsions.
— John P. Ward
