Letter from Michael Heidelberger to Linus Pauling

In this letter Heidelberger commented on a hypothesis regarding the chemical structure of antibodies and the location of the sites at which they bind to antigens developed by Linus Pauling, the world's preeminent physical chemist at the time. Pauling's article was published as "A Theory of the Structure and Process of Formation of Antibodies" in the Journal of the American Chemical Society 62 (1940), pp. 2643-2657.