The historical background of the 19th century electromagnetic theory is revisited from the standpoint of the opposition between alternative approaches in respect to the problem of interactions. The 19th century electrodynamics became the battle-field of a paramount importance to test existing conceptions of interactions. Hertz’s experiments were designed to bring a solid experimental evidence in favor of one of them. The modern scientific method applied to analyze Hertz’s experimental approach as well as the analysis of his laboratory notes, dairy and (...) private letters show that Hertz’s ‘‘crucial’’ experiments cannot be considered as conclusive at many points as it is generally implied. We found that alternative Helmholtz’s electrodynamics did not contradict any of Hertz’s experimental observations of transverse components as Maxwell’s theory predicted. Moreover, as we now know from recently published Hertz’s dairy and private notes, his first experimental results indicated clearly on infinite rate of propagation. Nevertheless, Hertz’s experiments provided no further explicit information on non-local longitudinal components which were such an essential feature of Helmholtz’s theory. Necessary and sufficient conditions for a decisive choice on the adequate account of electromagnetic interactions are discussed from the position of modern scientific method. (shrink)