January 9, 1941

Professor William C. Boyd

Department of Biochemistry

Boston University

School of Medicine

80 E. Concord Street

Boston, Massachusetts

Dear Professor Boyd:

I am enclosing a copy of our manuscript on serological reactions with simple substances, and I would be glad to have your comments on it. We have included mention of the substances referred to in your letter, rather than only the substance referred to in the published discussion of your work. Is this satisfactory to you?

Dr. Pressman has pointed out to me that it is easier to attach azo groups in the 4.5 positions of dihydroxynaphthalene than the 2.7 positions. Have I interpreted your formula correctly as the 2.7 derivative?

I don't think that there can be misunderstanding about the question of composition of precipitate versus final concentration of reagents when the discussion is detailed enough to be understood. If equilibrium is reached, the composition of the precipitate must be determined by the final composition of the solution. If equilibrium is not reached, this need not be so.

I do not feel that the lattice theory is necessarily right - that is I am willing to be convinced by the evidence, although I recognize that it is going to be difficult to find a crucial experiment. It seems to me that the available information tends to support the theory rather than to discredit it. For example, I have felt on reading your papers on agglutination that you usually observed separate agglutination of different cells, and observed clumping together only when conditions were just right. This would be expected from the framework theory. How do you explain the formation of separate clumps under various conditions?

Sincerely yours,

[Linus Pauling]

LP: jr