Double Helix

I have never seen Francis Crick in a modest mood. This has nothing to do with his present fame. Already he is much talked about, usually with great respect, and one day he may be considered an equal to Rutherford or Bohr. But this was not true when, in the autumn of 1951, I came to the Cavendish Laboratory of Cambridge University to join a small group of physicists and chemists working on the structure of proteins. At that time Francis was thirty-five, but almost totally unknown. Although some of his colleagues respected his quick mind and frequently asked his advice, he was often not appreciated, and most people thought he talked too much. Leading the unit to which Francis belonged was Max Perutz, an Austrian-born chemist who came to England in 1936. He had been collecting X-ray diffraction data from protein crystals for over ten years and was just beginning to get results. Helping him was Sir Lawrence Bragg, the director of the Cavendish. For forty years Bragg, a Nobel Prize winner and one of the first crystallographers, had been watching X-ray diffraction methods solve structures of increasing difficulty. In the immediate postwar years he was especially keen on the possibility of solving the structure of proteins, the most complex of all molecules. Somewhere between Bragg the theorist and Perutz, the experimenter was Francis, who occasionally did experiments but was more often interested in theories for solving protein structures. Often he had a new idea, became enormously excited, and would immediately tell anyone who was willing to listen. A day or two later he would often realize that his theory did not work and return to experiments, until he got bored with them and turned again to theory. These ideas brought an atmosphere of excitement to the laboratory, where experiments usually lasted several months to years. This came partly from the volume of Cricks voice; he talked louder and faster than anyone else, and when he laughed everyone knew where he was in the Cavendish. Most people enjoyed these exciting moments, especially when we had time to listen closely and to tell him when we lost the logic of his argument. But there was one significant exception. Conversations with Crick frequently upset Sir Lawrence Bragg, and the sound of his voice was often enough to make Bragg move to a safer room. Only infrequently would he come to tea in the Cavendish, since it meant he had to hear Crick's loud voice in the tearoom. Even if he stayed away, Bragg was not completely safe. On two occasions, the corridor outside his office was flooded with water pouring out of a laboratory in which Crick was working. Francis, with his interest in theory, had not properly connected the rubber tubes to his pump. At the time of my arrival, Francis's theories spread far beyond the boundaries of protein crystallography. Anything important would attract him, and he frequently visited other laboratories to see which new experiments had been done. Though he was generally polite to colleagues who did not realize the real meaning of their latest experiments, he did not attempt to hide this fact from them. Almost immediately, he would suggest a number of new experiments that would confirm his analysis. Moreover, he could not stop himself from later telling anybody who would listen how his clever new idea might move science forward.