molecular weight of polymer molecules. This started as a result of his research during World War II on synthetic rubber, but was extended to proteins and other macromolecules. In April 1966, Debye suffered a heart attack, and in November of that year a second one proved fatal. He is buried in the Pleasant Grove Cemetery (Ithaca, New York, US). War activities and controversies 2006 controversy In January 2006, a book (in Dutch) appeared in The Netherlands, written by Sybe Rispens, entitled Einstein in the Netherlands. One chapter of this book discusses the relationship between Albert Einstein and Debye. Rispens discovered documents that, as he believed, were new and proved that, during his directorship of the Kaiser Wilhelm Society, Debye was actively involved in cleansing German science institutions of Jewish and other "non-Aryan elements". Rispens records that on December 9, 1938, Debye wrote in his capacity as chairman of the Deutsche Physikalische Gesellschaft (DPG) to all the members of the DPG: In light of the current situation, membership by German Jews as stipulated by the Nuremberg laws, of the Deutsche Physikalische Gesellschaft cannot be continued. According to the wishes of the board, I ask of all members to whom these definitions apply to report to me their resignation. Heil Hitler! Many biographies published before Rispens' work, state that Debye moved to the US because he refused to accept German citizenship forced on to him by the Nazis. He planned his departure from Germany during a visit with his mother in Maastricht in late 1939, boarded a ship in Genoa in January 1940 and arrived in New York in early February 1940. He immediately sought a permanent position in the US and accepted such an offer from Cornell in June 1940. That month, he crossed the US border into Canada and returned within days on an immigration visa. He was able to get his wife out of Germany and to the US by December 1940. Although his son already was in the US before he departed, Peter Debye's 19-year-old daughter and his sister-in-law did not leave. They lived in his official residence in Berlin and were supported by Debye's official Berlin wages (he carefully maintained an official leave of absence for this purpose). Further, Rispens alleges that Albert Einstein in the first half of 1940 tried to prevent Debye from being appointed in the United States at Cornell. Einstein allegedly wrote to