Spiro was on sabbatical in 1962-1963 in London, mainly at the Postgraduate Medical School. He communicated with the Section on Gastroenterology by means of dictaphone tapes, a new technology, that enabled a sturdy ring of red tape to be mailed. He corresponded mainly with Walter Thayer who transcribed the tapes. The folder contains the transcripts, a few other letters sent by Spiro, and two examples of the tapes and envelope-mailers.