The short notice evokes memories of an experimental observation published in 1920 by B. Gudden and R. W. Pohl, and since known as the Gudden-Pohl effect. The important role played by the effect during the development of quantum solid state physics between 1920 and 1950 is stressed. Other scientific activities of B. Gudden are briefly mentioned as well., Ivan Pelant., and Obsahuje bibliografii