In the text “Electricity and Magnetism”, I propose a hypothesis about the whole mechanism for electricity and magnetism and their interactions, including the discussions about followings: 1, the possible existence of magnetic charges in protons and electrons where the positive and negative electric charges locate exactly; 2, the mechanism of the activation and deactivation of magnetic charges with in protons and electrons; 3, how electricity, magnetism and Lorentz effect interact with each other within hydrogen atom; The whole mechanism can provide a framework for hydrogen atom and solve the atomic stability issue.