The letters are: Marian Dale, Harvard School of Public Health, to Hunt, 1932 April 7; Hans Zinnser, Harvard Medical School, to Hunt, 1932 April 12; Hans Zinnser to Hunt, 1932 June 6; and Leroy D. Fothergill, Children's Hospital, Boston, to Hunt, 1932 June 20. The letters were donated by Willis R. Hunt in December 1967.