Letter from Phoebus A. Levene, Rockefeller Institute for Medical Research to Michael Heidelberger

In this letter Phoebus A. T. Levene related the positive reaction to Heidelberger's work by a European colleague, and recounted details of his European vacation. Heidelberger had first met the biochemist Levene during his initial exploratory visit to the Rockefeller Institute in 1911, when Levene recommended that Heidelberger study a year in Europe, specifically with Richard Willstatter in Zurich, to enhance his chances of receiving an appointment at a major research university in the United States.