XIII. Contributions to the molecular theory of induced magnetism

Abstract

As the facts of induced magnetism become better known, increasing interest attaches to molecular theories and increasing difficulty attends the theories that are current. Weber’s fundamental conception that the molecules of iron or nickel or cobalt are always magnets, and that the process of magnetising consists in turning them from many directions towards one direction, has been strongly confirmed by the now well established fact that there is a true saturation value, a finite limit to the intensity of magnetism, which may be reached or very closely approached by using a strong magnetic force. Without going further back, to 'enquire (with Ampere) how the molecules come to be magnets, we may take this conception as the natural starting point of a theory.