When working with wet photographic plates, I noticed that heat increased the sensitivity of the silver bromide emulsion. By 1871 I had devised a method of using dry plates and substituting nitro-cellulose plastic for glass plates, thus initiating the age of convenience in photography. Eight years later I patented bromide paper, developments of which are still used for black and white photographic prints.

obrien, nikolas. "joseph swan." en.wikipedia.org. wikipedia, 3/25/2011. Web. 25 Mar 2011. <http://en.wikipedia.org/wiki/Joseph_Swan>.