The last two equations together make a magnetic field oriented along the radius-vector (when q is positive) in the upper half-plane x$_{3}$ > 0 and opposite to the radius-vector in the lower half-plane: h = x | x | q M 8 π 1 | x | 2 x$_{3}$ | x$_{⊥}$ | . (46) The magnetic lines of force make a pencil of straight lines passing through the origin where the charge is located and go radially from/to the charge with their density being the cotan- gent of the observation angle increasing towards the axis 3 , where it is singular. The mag- neton q M / (8 π ) is proportional to the pseudoscalar G ; in perturbation theory it has the fine structure constant α as its overall factor. The result (46) is approximation-independent, but holds true only as long as the magnetic field produced by the charge may be considered as a small perturbation of the background field. It is worth noting that analogous magneto-electric phenomenon should be present in a plasma with external magnetic field. The reason is again in the mixing – after plasma is added – of basic vectors [13] (see also [5]), which are electric and magnetic carriers in the magnetized vacuum alone. If the plasma is charge-symmetric, e.g. consists of equal numbers of positively and negatively charged otherwise identical particles, say electrons and positrons, the vector ♭ (1) µ ∣ G =0 from (7) linearly combines with the pseudovector ♭ (2) µ ∣ G =0 = ( ˜ F k )$_{µ}$, to become an eigenvector, unlike the situation considered above, while ♭ (3) µ ∣ G =0 = ( F k )$_{µ}$ remains an eigenvector. The pseudoscalar, needed for this combination, is built of the same pseudovector contracted with the vector of 4-velocity of the plasma. It plays the role of G . For a more general charge-non-symmetric case, say, electron gas or a gas of ionized atoms, the situation is even more rich, because all the three basic vectors mix. V. DEGENERACIES We have to consider the degeneracies of the polarization matrix taking place for two special kinematical conditions owing to the symmetries of the external field. For the real or virtual excitations directed parallel to the external field in the special frame the polarization operator is symmetric under spacial rotations around the common field direction 3 , since the external field is invariant under them, while the excitation does not introduce an additional anisotropy in the perpendicular plane owing to the relation 22