We present an axiomatic foundation of non-integrable phases of Schr"{o}dinger wave functions and use it for interpreting Dirac's 1931 pioneering article in terms of the electromagnetic 4-potential. The quantization of the electric charge in terms of $e$ implies the quantization of the dielectric flux through closed surfaces $bar{Psi} := oiint vec{D} cdot mathrm{d}vec{S}$ in terms of the `Lagrangean' dielectric flux quantum $Psi_D=e$. The quantization of the analogous magnetic monopole charge in terms of $g$ implies the quantization of the magnetic flux through closed surfaces $bar{Phi} := oiint vec{B} cdot mathrm{d}vec{S}$ in terms of the `Diracian' magnetic induction flux quantum $Phi_B=g=h/e$, and textit{vice versa}. Here, the question is raised, if the quantization of the magnetic charge (and hence field) in a given volume depends on the total electric charge in that volume. Furthermore, we have $Phi_B/Psi_D = g/e = h/e^2 = R_text{K}$, the von Klitzing constant, the basic resistance of the quantum Hall effect. $R_text{K}$ and the vacuum permittivity $varepsilon_{0}$ and permeability $mu_{0}$, respectively, combine to two natural speed constants different from that of light in vacuum $c$.%footnote{This article is an extension of a talk presented (in German) before the Physical Society at Berlin, Febr. 15, 2023, url{https://www.dpg-physik.de/veranstaltungen/2023/mhb-agsen-2023-02-15}.}