The Crick Papers: 1952 At the Cavendish 1/3/03. By Giles Newton In 1949, Francis Crick joined the Medical Research Unit at the Cavendish Laboratory.

1952 At the Cavendish Group portrait of Physics Research students at the Cavendish Laboratory, Cambridge. James Watson and Francis Crick are in the first row standing, sixth and seventh from the left, respectively.

The Cavendish Laboratory is the University of Cambridge's Department of Physics. Founded in 1871, is was the first specially designed physics laboratory in the world. It is named after the scientist Henry Cavendish (1731-1810), who is generally credited with having discovered hydrogen and with one of the earliest accurate calculations of the density of the earth.

In 1949, Francis Crick joined the Medical Research Unit at the Cavendish. There, a team led by Max Perutz was using X-ray crystallography to discover the structure of proteins – a subject that became the topic of Crick's PhD thesis.

In 1951, James Watson arrived at the Cavendish and met Crick. The two quickly became friends and embarked on an attempt to uncover the structure of DNA. Crick brought to the project his knowledge of X-ray diffraction, while Watson brought knowledge of phage and bacterial genetics.

Combining evidence from biochemistry, X-ray diffraction images created by Rosalind Franklin and Maurice Wilkins, and physical clues from molecular models, they determined the three-dimensional structure of the DNA molecule to be a double helix.

This discovery was published in the 25 April 1953 edition of the journal Nature. The order of the names on the paper (Watson and Crick) was decided by the flip of a coin. This paper was quickly followed by another that suggested a mechanism for the replication of DNA.