Rosalind Franklin DressRosalind Elsie Franklin was an English chemist and X ray crystallographer who made contributions to the understanding of the molecular structures of DNA, RNA viruses, coal, and graphite. Although her works on coal and viruses were appreciated in her lifetime, her contributions to the discovery of the structure of DNA were largely recognized posthumously. Franklin is best known for her work on the X ray diffraction images of DNA, particularly Photo 51.