The metric coefficients g/sub 00/ and g/sub 11/ of both the Schwarzschild and Reissner-Nordstroem metrics satisfy the relation g/sub 00/g/sub 11/ = -1. A coordinate-independent statement of this relation using the eigenvalues of the Einstein tensor is given. By considering the relation between the metric coefficients to be valid inside a charged perfect-fluid distribution, it is shown that the mass-energy density and the pressure of the distribution are of electromagnetic origin. In the absence of charge, however, there exists no interior solution. A particular solution which confirms the same and matches smoothly with the exterior Reissner-Nordstroem metric is obtained. This solution represents a charged particle whose mass is entirely of electromagnetic origin.