April 15, 1946

Mr. Allan Maccoll

Sir William Hamsey and Ralph Forster Laboratories

University College

London W. C. 1, England

Dear Mr. Maccoll

Your manuscript has now been found, among some other papers in my laboratory, and I observe that it is marked received September 11, 1945 and, moreover, I see that my negligence is far more serious than I had thought hitherto, because in your letter of July 17 you ask me to forward the manuscript to the Journal of Chemical Physics. I apologize for having failed to do this.

I am not now sending the manuscript on to the Journal of Chemical Physics, because of the remark in your letter of March 5 that you are planning to publish it in the Journal of the Chemical Society. If you have not yet submitted it, and you would prefer to have it appear in the Journal of Chemical Physics, please let me know at once, and I shall send the copy which I have to the editor.

I have read the manuscript with interest, and I think that it is worthy of publication. I find it difficult to decide about the reliability of the simple calculation when applied to such complex phenomena; that is, in the interpretation of the difference in energy of two stationary states — I believe that the application to the calculation of resonance energy alone is somewhat more reliable. The only feature of the work which surprises me is the very small value, 0.20 v.e., of the nitrogen-nitrogen integral y. It is true that the energy of a single bond between two nitrogen atoms is very small; but the very great energy of the triple bond, in the nitrogen molecule, indicates that the exchange integral y is very large rather than very small.

I trust that you will continue to work in this interesting field, and I shall look forward to hearing from you again, and to meeting you at some time in the future.

Sincerely yours,

Linus Pauling

LP:gw