1963: Peter J. W. Debye (1884–1966)

The 1963 Priestley Medal was presented to Nobel Laureate Peter J. W. Debye at the 144th ACS national meeting in Los Angeles. His long and distinguished scientific career—which spanned critical years in Nazi Germany—has been critically examined and discussed well after his death in 1966.

Debye was born in Maastrict, the Netherlands. In 1905, he received a degree in electrical technology from RWTH Aachen University, Germany. In 1908, he received a Ph.D. in physics from the University of Munich. And in 1911, he succeeded Albert Einstein as professor of theoretical physics at the University of Zurich and then assumed a similar position at the University of Utrecht in 1912.

Debye’s first major scientific contribution came in 1912 with the application of the concept of dipole moment to the charge distribution in asymmetric molecules, developing equations relating dipole moments to temperature, dielectric constant, and other molecular properties. Dipole moments are measured in debyes, a unit named in his honor. He received international recognition for his equations for heat capacities of molecules at low temperatures, as well as for his theory on the scattering of light by polymers in determining molecular structure. Both his work on the X-ray analysis of molecular structure and his part in developing the Debye-Hückel theory of the distribution of ions brought him widespread recognition.

But it was his concern with molecular forces that garnered Debye the 1936 Nobel Prize in Chemistry. He was cited “for his contributions to our knowledge of molecular structure through his investigations on dipole moments and on the diffraction of X-rays and electrons in gases,” according to the website Nobelprize.org. His subsequent studies on polar molecules and X-ray diffraction of free molecules opened new research frontiers in physical chemistry.

Although Debye served in a variety of academic posts in Europe, it was his tenure as director of the physics section of the Kaiser Wilhelm Institute in Berlin from 1934 to 1939 that would later tarnish his scientific legacy. He oversaw the institute at a time when Jewish scientists were being forced from academic positions by the Nazis. Debye, it turns out, signed a letter ordering the resignation of Jewish colleagues from the physics institute. The letter was signed “Heil Hitler.” Scholars have disagreed over whether Debye was forced to sign and distribute the letter and whether it constitutes collaboration. Finally, as war began to spread throughout Europe, Debye seized the opportunity to become a professor of chemistry at Cornell University, leaving Europe for good. He became head of the department there, a position he held until 1950 when he retired and became an emeritus professor.

In 2006, the letter that seemed to implicate Debye as a Nazi collaborator surfaced in a book, “Einstein in the Netherlands,” by German science writer Sybe I. Rispens. Almost immediately, the University of Utrecht removed Debye’s name from its Debye Institute for NanoMaterials Science and the University of Maastrict stopped distributing a Debye scientific award. But investigations by the two universities in the Netherlands and by Cornell have since cleared Debye’s name. His name is back on the institute, but the University of Maastrict stuck by its earler decision. Historians and others have pointed out that Debye hired many Jewish faculty members at Cornell at a time when anti-Semitism was apparent in the hiring practices of other Ivy League institutions.—William Schulz