Titles
- Letter from Florence R. Sabin to Rudolph J. Anderson2
- Letter from Frank B. Hanson to Edward L. Tatum1
- Letter from Frank S. Burch to Clarence Dennis1
- Letter from Fred E. Wright, National Academy of Sciences to Oswald T. Avery1
- Letter from George W. Beadle to Edward L. Tatum2
- Letter from Good Housekeeping Magazine to Florence R. Sabin1
- Letter from H. B. Zimmermann to Clarence Dennis1
- Letter from H. H. Dale to Alan Gregg1
- Letter from Harvey Cushing to Alan Gregg1
- Letter from Helen Keller to Florence R. Sabin1
- Letter from Hugh S. Taylor, Princeton University to Michael Heidelberger1
- Letter from K. Starr Chester, Rockefeller Institute for Medical Research to Michael Heidelberger1
- Letter from Kai O. Pedersen to Michael Heidelberger4
- Letter from Karl A. Connell to Virginia Apgar2
- Letter from Leonard Colebrook to Alan Gregg1
- Letter from Lewis Hackett to Fred L. Soper1
- Letter from Linus Pauling to H. D. Springall1
- Letter from Linus Pauling to Professor Noyes1
- Letter from Linus Pauling to Warren Weaver7
- Letter from Lloyd H. Ziegler to Lawrence Kolb1