Pauling knew that Todd had been working with purified nucleotides and asked him to
send samples for x-ray analysis. "Dr. Corey and I are much disturbed that there has
been no precise structure determination reported as yet for any nucleotide. We have
decided that it is necessary that some of the structure determinations be made in
our laboratory. I know that the Cavendish people are working in this field, but it
is such a big field that it cannot be expected that they will do the whole job." He
then wrote his son Peter and Jerry Donohue that he was hoping soon to complete a short
paper on nucleic acids.
But the structure still was not quite right. Everything would seem to fall into place,
then Corey would run another set of calculations showing that the phosphates did not
quite fit. Pauling would readjust and tinker, bend and squash, so close to the answer
yet unable to make it all fit perfectly. Perhaps it would never be perfect. Perhaps
what he had would have to do.
On Christmas Day Pauling took the unusual step of inviting a small group of colleagues
into his lab to have a look at his work on DNA. He was tired of the niggling problems
with his model and ready for some good news. He got it from his small audience, who
expressed enthusiasm for his ideas. Much cheered, Pauling spent the last week of the
year working with Corey on a final manuscript.
On the last day of December 1952, Pauling and Corey sent in their paper, "A Proposed
Structure for the Nucleic Acids," to the Proceedings of the National Academy of Sciences. It was uncharacteristically tentative. This was "a promising structure," Pauling
wrote, but "an extraordinarily tight one"; it accounted only "moderately well" for
the x-ray data and gave only "reasonably satisfactory agreement" with the theoretical
values obtained by the Crick formula; the atomic positions, he wrote, were "probably
capable of further refinement."