  We suppose that vacuum is filled with a kind of continuously distributed
matter which may be called the $\Omega(1)$ substratum, or the electromagnetic
aether. Suppose that the time scale of a macroscopic observer is very large
compares to the the Maxwelllian relaxation time of the $\Omega(1)$ substratum.
Thus, the macroscopic observer concludes that the $\Omega(1)$ substratum
behaves like a Newtonian-fluid. Inspired by H. A. Lorentz, we speculate that
electric charges may be extremely small hard spherical sources or spherical
sinks with finite radii. Based on the spherical source and spherical sink model
of electric charges, we derive Coulomb's law of interactions between static
electric charges in vacuum. Further, we derive a reduced form of the Lorentz's
force law for static electric charges in vacuum.
