The author investigatess the structure of material forces in electromagnetic materials. For this purpose, he introduces scalar and vector potentials to express the electromagnetic fields and introduces the Lagrangian density. He then derives the governing equations as the associated Euler equations. In structured or micro-structured materials, an Eshelby-like stress tensor can be assembled by following a simple rule. By appealing to this rule, the author is able to propose an expression for the Eshelby tensor in electromagnetism. The paper is well written and may interest several readers working in the area of electromagnetism.