Pauli gives a few results concerning the S-matrix which where found by his collaborator Ma in Princeton. He doesn't believe that the S-matrix is a fundamental concept which will play a basic role

Pauli is working on the w-space of Pais. He asks about progress of Heisenberg's work.

Pauli hopes to meet Heisenberg in Bern.

Pauli replies to Heisenberg's letter of 19 June.

Pauli replies to Heisenberg's letter of 25 December, especially about field-operators. He writes about his paper for the forthcoming meeting in New York on quantum electrodynamics.

Pauli asks about the character of the conference of Nobel prize winners in Lindeau because possibly he will attend this time. He asks about a symposium in Karlsruhe on the limits of physics.

Pauli comments and questions in connection with Heisenberg's letter of 26 December which Pauli regards as a progress.

Pauli gives some qualifications of his last arguments about the proportion of the S-matrix.

Pauli preliminarly replies to Heisenberg's last letter. He does not agree with Heisenberg's treatment of the mathematics of the problem. He writes of a recent letter from Princeton with the news about Mrs. Wu's experiments with "killing" parity. He thinks that agrees with a suggestion by Salam who connected the laxk of left-right symmetry with the vanishing of the rest mass of the Neutrino.