Pauli makes comments on Ma's paper. He is against the waste of too much work on purely classical theory. He makes comments on an earlier letter of Ma, concerning a certain invariant factor.

Pauli writes on the "universal length" and about his discussions with Stern concerning the connection of entropy and observation.

Pauli asks questions about the unitary representations of the Lorentz group.

Pauli announces that he is going to send Bohr a copy of his article for the Einstein volume containing a survey of the epistemological situation in quantum mechanics and is eager to hear Bohr's opinion on it. He also asks Bohr to paper for the issue of "Dialectica" on complementarity and talks about a group of experimental physicists in Rome.

Pauli encloses a note on the magnetic moment of the triton, which can be explained by exchange momenta given by the meson theory.

Pauli says that the magnetic moment of the triton can only be accounted for by the use of exchange current.

Pauli gives further details about the impending visit to Sweden.

Pauli comments on a paper by Pomeranchuk (Moscow) which generalizes the Lamda-limiting process so that logarithmic divergencies are made finite.

Pauli congratulates Bohr on his article for the Einstein volume and makes some little corrections. He announces an international physics conference in Zürich and hopes that Bohr will accept an invitation.

Pauli is glad to have Bohr's letter of May 11th and he hopes that Bohr will soon be back in Copenhagen. Einstein has sent Pauli an article for "Dialectica", which essentially repeats his old arguments. Pauli encloses copies of his letter to Einstein and also his reply. Pauli did not agree with Einstein's point of view expressed in his letter and he did not continue this correspondence. Pauli urgently needs Bohr's promised article for "Dialectica". A short address clarifying some concepts used by Bohr would be sufficient without any discussions of historical questions. They all hope that Bohr will be able to come to the conference in Zürich.