In previous papers of F. and H. London supraconductivity has been described as a phenomenon, in which the current density is not connected with the electric field, as in normal conductors, but depends on magnetic field strength according to the equation Λ c curl J = - H with B = H and with Λ = m / ne 2, a new characteristic constant which contains the number n of supraconducting electrons. the behaviour of the electric field is not completely determined by this equation. Using Maxwell's induction law one can conclude from (1) only that Λ c curl j = c curl E or Λj = E + grand μ, where the physical signifance of grad μ is yet unknown.