Dorothy Crowfoot Hodgkin lectured at the Lindau Meetings five times and repeated her basic story several times. The story is about the development of X-ray diffraction as a method to determine the structure of biologically important organic molecules, such as insulin. This time she tells a very personal version of the story, with a lot of photographs that, sadly enough, are not in the archive of the Lindau Meetings. Some photographs are of beautiful organic crystals, the growing of which is an art in itself. Other photographs are of her mentors and colleagues.
Her foremost mentor, John D. Bernal, plays a large role in her lecture and she has even gone through his correspondence that is kept in an archive in Cambridge. Bernal, who was born in Ireland 1901, was the first to show clearly that even organic molecules can give rise to well defined X-ray diffraction diagrams. This discovery was made in Cambridge in 1934, using crystals of pepsin. According to Dorothy Crowfoot Hodgkin, his important discovery was that the crystals had to be kept in their mother liquid. This is because they contain water and may become deformed if dried. Bernal put the only millimetre large crystals in a small glass tube that had been sealed at the ends. I was particularly interested in hearing that the crystals for this groundbreaking experiment had been grown where I was born and went to school and university, in Uppsala, Sweden.
The pepsin crystals were grown by a visitor to the laboratory of The Svedberg, the Swedish Nobel Laureate in Chemistry 1926. Svedberg’s invention, the ultracentrifuge, evidently was a strong attractor for scientists from all over the world interested in sorting large organic molecules. So one of Bernal’s friends happened to pass by and saw the crystals and brought them back to him. This kind of story is by no means unique and shows the importance of scientific exchange and travel.