The chapter discusses the possibility of interpreting the predictive explanation of the Zeeman Effect as a case of continuity between Lorentz theory of Electron and Relativistic Electrodynamics. The result is negative and it seems so both in structuralist and in selective realist terms. The strategy of the case study is not to look for elements of continuity with modern reading in the old explanation. Rather, I propose a comparison between these two successive phases of electrodynamics