Richard Leach Maddox (4 August 1816 – 11 May 1902) was an English photographer and physician who invented lightweight gelatin negative dry plates for photography in 1871.

The eminent photomicrographer of the day, Lionel S. Beale, included as a frontispiece images made by Maddox in his manual 'How to work with the Microscope'[1] In photography, the Collodion process was invented in 1851 by Frederick Scott Archer.

He suggested in the 8 September 1871 British Journal of Photography article An Experiment with Gelatino-Bromide that sensitizing chemicals cadmium bromide and silver nitrate should be coated on a glass plate in gelatin, a transparent substance used for making candies.

Eventually Charles Harper Bennett made the first gelatin dry plates for sale; before long the emulsion could be coated on celluloid roll film.

silver nitrate with a binder of albumen - derived from egg white, and widely used in printing-out paper in the nineteenth century - had been coated on glass; but these proved to be too insensitive for camera use.

He combined silver bromide with "vegetable gummy matters" (lichen, linseed, quince), and "starchy substances" (rice, tapioca, sago).

Maddox freely gave his discovery of the dry gelatin process to the world, saying (to W. J. Harrison, in a letter of 1887) that "[I had] no thought of bringing the subject into notice until it had been lifted from the cradle".

Maddox, at the initial stage of invention, could probably produce only 'lantern slides' contact-copied from his microscope plates, the slow speed being impracticable for camera lens images.

The reason for this is that the editor of the British Journal of Photography, J. Traill Taylor, had fallen ill and made a desperate appeal for contributions from his friends.

[5] Similarly, the editor of the American Amateur Photographer, in the same month, found that "no honor is great enough to bestow on a discoverer who acts so generously in giving his process to the world".

The obituary in the Almanac of the British Journal of Photography was not entirely uncritical, saying that the "real difficulties of the process were encountered and overcome by those who came after Maddox...whose ideas were not altogether practicable."