A shekara ta 1896, jim kadan kafin ya koma daga Leiden zuwa Amsterdam, ya auna rabuwa da layin bakan ta hanyar filin magnetic mai karfi, wani binciken da aka sani da tasirin Zeeman, wanda ya lashe kyautar Nobel a Physics a 1902. Wannan binciken ya shafi binciken tasirin filayen magnetic a kan tushen haske. Ya gano cewa an raba layin bakan zuwa abubuwa da yawa a gaban filin magnetic. Lorentz ya fara jin labarin lura da Zeeman a ranar Asabar 31 ga Oktoba 1896 a taron Royal Netherlands Academy of Arts and Sciences a Amsterdam, inda Kamerlingh Onnes ya sanar da waɗannan sakamakon.
Ƙasar Leiden