The chemical company that employed me, among other goods and services, produced photographic plates, which led my to some of his most impressive scientific innovations. In 1862, I patented the first commercially feasible procedure for carbon printing in photography. Then, having observed that heat increases the sensitivity of silver bromide emulsions, I invented the dry plate in 1871, followed by the development of bromide photographic paper in 1879.

obrien, nikolas. "molecular expressions." micro.magnet. micro.magnet, 3/25/2011. Web. 25 Mar 2011. <http://micro.magnet.fsu.edu/optics/timeline/people/swan.html>.