Hedwig Kohn

April 5, 1887 to 1964

Hedwig Kohn, signature, Department of Physics, University of Breslau 1930-1931

Before the Second World War, Kohn was one of only three women to gain the qualification required to teach physics at a German university (the habilitation).

She studied physics at Breslau from 1906 to 1913, gaining her doctorate in 1913. In 1930 she gained her habilitation qualification.

Hedwig Kohn, Physics Institute, Breslau, 1930-1931

As can be seen in the extract above, Kohn was an assistant at the Institute of Physics, located at Oranienstraße (see map below).

Hedwig Kohn, Oranien Straße, Breslau, 1933

Kohn was also teaching at the Institute of natural sciences and medicine in 1930-1931, as can be seen in this extract (below) from the University of Breslau handbook from that academic year.

Hedwig Kohn, Natural sciences, Univerity of Breslau, 1930-1931

Kreuzkirche can be seen in the map extract below.

Institute of Physics, Kreuz Kirche Straße, Breslau, 1930s

In addition, Kohn was teaching on a number of general physics courses in this year (see below), including on a beginner’s physics internship, jointly with other staff, three or six hours, according to choice, Wednesdays 3-6pm, and Sundays, from 9-12pm; on a practical physics for medicine course, for pharmacists, jointly with other staff, on Wednesdays, 3-6pm; finally here, she taught advanced physics, jointly with other staff, daily, full time.

Hedwig Kohn, physics teaching, University of Breslau, 1930-1931

The last entry in the Breslau handbook for 1930-31 (below) shows Hedwig Kohn teaching a seminar on atomic physics, jointly with Dr Senftleben, for two hours.

Hedwig Kohn, atomic physics, Unversity of Breslau, 1930-1931

When the National Socialist changes in legislation meant that she was banned from teaching in 1933, Kohn took up employment in industrial physics until 1939; soon after this she left Germany with the help of friends and colleagues and escaped to the USA.

Subsequently, Kohn taught physics first at Greensboro, NC, and then at Wellesley, MA, where she gained her professorship, won a research award; she retired in 1952.

At Breslau, Kohn had been a student of Otto Lummer, exploring the quantitative determination of light intensity. (Lummer was known for precision radiation measurements that contributed to the formulation of Planck’s radiation law.) In the earlier and later periods of her work, Kohn worked on the quantitative measurement of radiation intensity, contributed to atomic and molecular spectroscopy, and was involved in quantitative measurements of luminosity or temperature.


The website of the American Institute of Physics has some photographs of Kohn before the war in Germany, and after the war in the USA. In the pre-war images she can be seen with colleagues including Schafaer, Senftleben, and Reiche, who are outlined in these pages, as well as with eminent physicists Albert Einstein and Ernest Rutherford.


All black and white extracts on this page are from the 'Vorlesungs und Personal Verzeichnis der Schlesischen Friedrich Wilhelms Universität zu Breslau Winter Semester 1930/1931', and the equivalent handbook for 1935-1936, available online at the University of Wrocław.

The map extract is from the excellent fotopolska.eu.