April 26, 1939

Professor A.R. Todd

The University of Manchester

Manchester, 13

England

Dear Alex:

After we had decided definitely to come to Europe this summer, the political situation made such progress in the wrong direction that we have decided to remain undecided for a while. Perhaps Hitler's address scheduled for day after tomorrow will be sufficiently significant in one way or the other to make up our minds for us. If we do come, we shall arrive in England early in July, and we are looking forward to seeing you and Alison.

We moved into our new house on March 10, Linus' birthday, and, although we are not yet settled there, we have been very happy. The children enjoy especially the freedom of life in the country, and they seem to be happier than ever before. I have been very pleased to have a pleasant study in which to work, as well as to admire the views, and I have spent more time at home than formerly. Ava Helen and I are driving up to Deep Springs and to Berkeley over the weekend, starting tomorrow. It has been a year and a half since I have gone to Berkeley, and I am looking forward to seeing what G.N. Lewis's men have under way.

I wish to thank you for your words about Zechmeister. I understand that he is troubled by the political situation in Hungary, and has been considering the question of leaving the country. We have not made any definite decision regarding another appointment in organic chemistry here.

Niemann seems to be getting along very well--he has done a fine job in outfitting the laboratory this year. No matter what addition to the staff is made, Niemann will retain complete freedom for carrying on his own work, as you advised.

With best regards, I am

Sincerely yours,

LP.jr

April 26, 1939

Professor T. H. Hogness

Department of Chemistry

University of Chicago

Chicago, Illinois

Dear Thorfin:

I am sorry that I have delayed so long in writing you about your manuscript, which I am returning enclosed. I found the manuscript very interesting, and Drs. Coryell and Davies have also read it and made some suggestions. I forgot that you would return to Chicago from the Baltimore meeting before the boys who went to Baltimore from here would get hack, and so I delayed overly long in writing to you.

Your results are extremely interesting and I think that the change in the values of the interaction with change in salt concentration is especially interesting and difficult to interpret.

Coryell, Dodson, and I have sent some time ago a paper to the Journal of Physical Chemistry on hemoglobin in which there is a re-derivation of the oxygen equilibrium expression. This was accompanied by another paper by Coryell in which he discussed the use of Hill's equation and the value of Hill's n in determining the value of α from empirical data. I am enclosing a letter from Coryell in which he makes some remarks about your paper. The remark about one acid group rather than two per heme needs some explanation. In ay paper on oxygen equilibrium of hemoglobin I said that the experimental data did not fit the theoretical equation for one acid group per heme but did fit that for two acid groups per heme. Coryell discovered some time ago that actually both equations fit about equally well, and that I must have made a numerical error when I was trying to apply the one acid group equation.

Professor T. R. Hogness -2- Aprll 26, 1939

It seems probable that there is only one acid group per heme effective in this particular pH range.

Ava Helen and I are planning to be in Chicago from June 24th on for a few days, at the time of your symposium and we are looking forward to seeing you then.

With best regards, I am

Sincerely yours,

Linus Pauling

LP/jr