Pauli has waited quite a while since receiving Bohr's letter of February 8, because he hoped to be able to say something on Schwinger's answer to his long letter. Pauli did not receive any answer. One of Schwinger's pupils contacted Pauli, from which he has the impression that Schwinger takes the matter seriously. Meanwhile Pauli and Villars have completed the calculations mentioned at the end of of Pauli's letter to Schwinger. He has almost no doubts on the correctness of his results for the electron magnetic moment, although the argument is somewhat different from his own. Villars and Pauli will send a joint paper with all their calculations to the Einstein issue of the Rev. of Mod. Physics which is edited by Pais. He also says that the work on quantum electrodynamics in their institute is proceeding well.

Pauli writes about his visit to Sweden

Pauli discusses matrix representation of Maxwell's equations, relation of Heisenberg-Pauli to Dirac theory, problem of self energy. He opposes Dirac's interpretation of negative states and Bohr's views on continuous beta spectrum.