Mathisson went to Cracow in 1937 where he collaborated with Professor Weyssenhoff, who held the chair of theoretical physics in the Jagellonian University, working on the theory of spin particles.
Mathisson napunta sa Cracow sa 1937 kung saan siya sa collaborated Professor Weyssenhoff, na gaganapin sa silya ng panteorya physics sa Jagellonian University, nagtatrabaho sa teorya ng magsulid particles.