September 28, 1942

Professor Joel H. Hildebrand

Gilman Hall

University of California

Berkeley, California

Dear Joel:

When I reached home on September 20 I found the accompanying manuscript waiting for me. It had been mailed on September 10 by Dr. Long, at your request. Dr. Schomaker and I have read the manuscript with much interest, and thank you for sending it on to us.

Dr. Schomaker has calculated isothermals from the DF data at five temperatures, and has interpreted them by the method which he has applied to the HF data of Fredenhagen. He would be very glad if you would send him the numerical data corresponding to the isothermals for HP as given in Figure 3.

I shall not mention a few minor points in the manuscript, which will no doubt be taken care of while you are pruning the paper for publication. The main suggestion that I make is that a change in emphasis on the nature of the polymerization seems to be called for. Your data look good, and I think that it is doing them an injustice to be so hesitant to accept the evidence which they give that a single polymerization, to a hexamer, is not sufficient. The evidence of the electron diffraction work and of Fredenhagen's 299° curve together with your own data, all indicate that polymers other than the hexamer are important. Of course, you recognize this in the manuscript, but the emphasis on the hexamer in the manuscript is so strong that a reader might well carry away the wrong impression. The fact that Dr. Schomaker is able to account for the data satisfactorily by assuming equal equilibrium constants for successive polymerizations above the third might make it desirable to cut down the discussion given the hexamer, and to mention in any case that values of quantities calculated on this basis are presumably to be interpreted as averages for various polymers.

If you would like to mention in your paper that Dr. Schomaker is going to publish his conclusions about polymers of HF obtained from your data and other data in connection with his electron diffraction work, he could communicate any additional results that he has obtained to you, to help in wording the statement about his work.

Sincerely yours,

Linus Pauling

LP:jr