After teaching a course on electromagnetic oscillations in the winter of 1913–14, Hilbert's interest in physical issues was kept alive although it was perhaps less intensive than during the previous two years. In June 1914, he published the third part of his work on the foundations of the theory of radiation (§ 5.3.4 above), and about the same time two of his students completed doctoral dissertations on physical topics: Bernhard Baule ("Applications of the theory of integral equations to the theory of the electron and the theory of dilute gases") and Kurt Schelenberg ("The applications of integral equations to the theory of electrolysis") (§ 5.3.5 above).