Richard Willstätter at the Eidgenössische Technische Hochschule. There he perfected the synthesis of cyclooctatetraene, an important intermediate in organic research. Willstätter helped his somewhat impecunious American student by sharing the cost of laboratory supplies with him, arranging that when expensive materials, such as silver nitrate, were to be bought, it was his turn to pay, while Heidelberger took turns buying cheaper materials like sulfuric acid. "Better training than that you couldn't have," Heidelberger summed up his experience with Willstätter. They remained friends for three decades, through Willstätter's flight from Germany in 1938 and until his death in Switzerland in 1942. While visiting relatives in Germany on his return from Zurich, Heidelberger received a telegram from his father relating an offer of a position of Fellow of the Rockefeller Institute, conditional upon a personal interview and approval by the institute's director, Simon Flexner. Rockefeller Institute Heidelberger passed muster, and in September 1912 began working in Walter Abraham Jacobs' laboratory on a derivative of hexamethylene tetramine, a complex that seemed to prolong the life of monkeys suffering from polio, and that Flexner hoped could be adapted for use in humans. Results appeared promising at first, but Heidelberger and Jacobs later attributed them to loss of virulence of the virus. In the summer of 1915, after attending officer training camp in Plattsburgh, New York, for a proposed volunteer army (an outgrowth of the movement to prepare the United States for entry into World War I) and earning a commendation as a marksman, Heidelberger traveled to Lake Kezar in Maine for a vacation. After performing Pergolese's Nina there, his piano accompanist exclaimed, "meet Nina," and in walked a young lady, Nina Tachau. They were married in 1916 to the strains of a wedding march composed by Heidelberger. She was a writer and activist for the New York chapter of the League of Women Voters and, during the 1940s, for the American Association for the United Nations. After her death from cancer in 1946, Heidelberger continued her work on behalf of the United Nations, and was a member of the U.S. delegation to meetings of the World Federation of United Nations Organizations in Prague, Bangkok, and other cities. He met his second wife Charlotte Rosen at a concert. She was the violist in a Mozart trio in which Heidelberger performed. They married in 1956. For ten years prior to her death in 1988, he took