13 September 1957
Dr. F. H. C. Crick
I had intended to have a chat with you, when I saw you in Cambridge this summer, about the three hydrogen bonds between guanine
and cytosine, but I forgot to do so. Now I have been jogged into thinking about the matter again by reading your article
in The Scientific American.
I suppose that you saw the paper that Professor Corey and I published in Archives of Biochemistry and Biophysics last year,
in which the matter is discussed. I enclose a reprint.
It seems to me that there is no justification whatever for continuing to show guanine and cytosine with only two hydrogen
bonds, as you do in The Scientific American article, both in the text and in the figure. What do you have to say?
With best regards, I am
cc: J. D. Watson