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Codebreakers: Makers of Modern Genetics

The Francis Crick papers

By discovering (with James Watson) the double helix of DNA, and helping to crack its code, Francis Crick laid the foundations of modern molecular biology.

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Collection overview

No one played a more central role in the biological revolution of the 1950s and 1960s than Francis Crick (1916-2004). Never the 'solitary genius', he deliberately sought others from whom his incandescent intellect could strike sparks. His papers and correspondence document the ferment of ideas that he generated wherever he went, both in himself and in others.

Working at Cambridge with the 23-year-old geneticist James Watson, Crick made his first great discovery in 1953. Model-building and mathematics revealed the double helical structure of DNA, aided by crucial glimpses of experimental results obtained by Maurice Wilkins and Rosalind Franklin at King's College in London. Debates about the credit for the discovery continue to this day, and correspondence at the time shows that all involved knew it was a contentious issue.

Crick lecturing
Francis Crick lecturing, 1975
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Crick was a conscientious note-taker, and a careful filer of unpublished drafts. His records of the meetings he attended and trips he took provide a chronological backbone to the DNA story, and the story of his subsequent work. Through the correspondence and unpublished material, such as his notes to the 'RNA Tie Club' started by George Gamow, you can see how Crick's mind leaped from one problem to the next, addressing the fundamental theoretical problems of heredity and challenging his colleagues to solve them through experiment.

Crick wrote as he thought, with uncompromising directness and clarity, and did not spare the feelings of those with whom he disagreed. He was driven by a conviction that all of biology could eventually be explained through physical processes, and therefore opposed vitalism in any form. He saw no role for religious belief, and enthusiastically supported proponents of eugenic 'improvement'. He was always willing to enter debate with those he disagreed with, and so his papers offer a unique insight into half a century of evolving views on the relationship between science, nature and society.

The bulk of Crick's personal archive is not in this collection but at the University of California at San Diego; however, the close friendships he formed among his scientific colleagues ensure that his exchanges with them reveal every facet of his forceful personality.


Francis Harry Compton Crick was born in 1916 near Northampton, England, the son of a shoe-factory manager. He studied physics at University College London and by the outbreak of World War II had begun a PhD on the viscosity of water.

Summoned to do war work for the Admiralty, he made important contributions to the development of mines for the Royal Navy. Meanwhile he read Erwin Schrödinger's 'What is Life?', and decided to switch from physics to biology. He began another PhD in 1950 at the Medical Research Council's unit at the Cavendish Laboratory in Cambridge, where Max Perutz was using X-ray diffraction to uncover the molecular structure of proteins.

Replication of DNA

A set of notes on 'The Replication of DNA', c. 1958
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When James Watson arrived from the USA a year later, they began to work together on the structure of DNA. In 1953 they published their landmark paper in 'Nature', describing the twin chains of nucleotides wound into a double helix that provided the physical basis for inheritance in all living things. Two big questions remained: how was the genetic information encoded, and how was the code translated into proteins? Crick's restless imagination and gift for collaboration proved central to the solution of both problems. He and Watson shared the Nobel Prize in Physiology or Medicine in 1962.

Crick was primarily a theorist, leaving it to others to confirm his ideas through experiment. In the 1970s he turned to thinking about the neural basis of consciousness, and moved to the Salk Institute in California, where he remained for the rest of his life. Throughout his career, he was known for his loud voice and braying laugh, and his sharp mind and ebullient personality were in demand wherever he went.

Originals held by...

This material is held by the Wellcome Library where originals may be consulted.

View details in the Archives and Manuscripts catalogue

To produce a really good biological theory one must try to see through the clutter produced by evolution to the basic mechanisms lying beneath...

Francis Crick, 'What Mad Pursuit', 1990

Digitised book

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Read the full text online

Foundations of genetics

In The Timeline

1953: James Watson and Francis Crick publish the double helix structure of DNA

James Watson and Francis Crick publish the double helix structure of DNA

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