Women were granted the right of habilitation in Prussia in 1920, and in 1922 Meitner was granted her habilitation and became a Privatdozentin. She was the first woman to receive her habilitation in physics in Prussia, and only the second in Germany after Hedwig Kohn. Since Meitner had already published over 40 papers, she was not required to submit a thesis, but Max von Laue recommended that the requirement for an inaugural lecture not be waived, since he was interested in what she had to say. She therefore gave an inaugural lecture on "Problems of Cosmic Physics". From 1923 to 1933, she taught a colloquium or tutorial at Friedrich Wilhelm University each semester, and supervised doctoral students at the KWI for Chemistry. In 1926, she became an außerordentlicher Professor (extraordinary professor), the first woman university physics professor in Germany. Her physics section became larger, and she acquired a permanent assistant. Scientists from Germany and around the world came to the KWI for Chemistry to conduct research under her supervision. In 1930, Meitner taught a seminar on "Questions of Atomic Physics and Atomic Chemistry" with Leó Szilárd.