Dr. Kersten Hall, an Honorary Fellow, in the School of Philosophy, Religion and History of Science, posts about the pioneering scientist, Florence Bell.

At first sight Florence Bell’s PhD thesis, now available online, seems to be an unlikely scientific milestone. Its description of X-ray studies of the fibrous proteins found in jellyfish, shark fin, and rare diseases of hair hardly seem likely to set scientific pulses racing. But amongst this eclectic mix of subjects, one chapter stands out. It contains a series of blurry photographs which helped lay the foundations for one of the biggest scientific landmarks of the 20th century.  This was discovery of the structure of DNA the carrier of genetic information.

The front page of Florence Bell’s 1939 thesis. Image credit University of Leeds Library.

Bell’s work on DNA had an unlikely origin. She arrived in Leeds in 1937 to take up the post of research assistant to the scientist William Astbury in the Department of Textile Industries.  He had made X-ray studies of the molecular structure of wool fibres. From this early work, Astbury established himself as a pioneer in applying the method of X-ray crystallography to the study of biological fibres such as hair, nail and wool.  Astbury became convinced that the best way to understand the complexity of living systems was through studying the structure of the giant molecules, such as protein fibres, from which they were made. He popularised this approach under the name ‘molecular biology’.

As Astbury’s ambitions grew, he needed the help of a skilled X-ray crystallographer.  He quickly recognised Bell’s talents and when the Institute of Physics held a conference in Leeds in 1939, he chose her to present the work of his laboratory on textile fibre structure.  The event was reported in the local press with the stunned headline ‘Woman Scientist Explains‘. What the newspapers could never have anticipated was that thanks to her PhD thesis published that year, the legacy of Bell’s work was to go far beyond the woollen industry of West Yorkshire.

Although today, DNA is well known for being the carrier of genetic information, at the time Bell was doing her research things were very different. Most scientists believed it to be an extremely dull molecule, but Bell recognised it might have some important role in biology:

‘Possibly the most pregnant recent development in molecular biology is the realisation that the beginnings of life are closely associated with the interactions of proteins and nucleic acids ‘(Bell, 1939, p.63)

DNA fibres
Photograph of diffraction patterns from DNA fibres taken by Florence Bell. Image credit University of Leeds Library.

From her X-ray studies, she proposed an early model of how the molecule might function and although we know that many features of this model were incorrect, her work was invaluable. She demonstrated for the first time that X-ray crystallography could be used to reveal the structure of DNA and laid the foundations for work by the scientists Rosalind Franklin and Raymond Gosling.   Their X-ray studies of DNA were crucial in solving its double-helical structure.

Unfortunately Bell’s work on DNA came to an abrupt end when she was called for military service during World War Two, after which she immigrated to the United States. Here she gave up her scientific career to look after her family and, presumably to reflect this change, when she died in 2000 her occupation was listed as ‘housewife’. But thanks to her PhD thesis, she was also an important figure in the story of DNA who has for too long remained in the historical shadows.

Dr. Kersten Hall is the author of ‘The Man in the Monkeynut Coat: William Astbury and the Forgotten Road to the Double-Helix.’