While it was early people who saw fluorescent light, Sir George Stokes was one of the first people to actually be able to explain it with any degree of certainty. He was working at the University of Cambridge, and he was the one who named the phenomenon fluorescence. He got the name because fluorite is a mineral that would fluoresce quite a bit because of the impurities that it had. He used work of Faraday and Maxwell, who worked with electricity and light earlier, to help him explain the reasons behind the fluorescing.
In 1856, a German glassblower was actually the one who created a mercury vacuum pump, and this was able to remove the air from a glass tube better than anything that had come before it. When they would pass an electrical current through the glass tube, it would give off a green light. Because it was so different, it was actually popular simply as an amusement. Little did anyone know just how important those early discoveries would be in later years.