Pauli writes about Gorter's preprint on 58 co-experiments and about a note by Salam.

Heisenberg replies to Pauli's arguments about the splitting of the dipole ghost by an interaction energy, and about the problem of causability in connection with his theory.

Pauli talks about his plans for a journey to England and Copenhagen. He writes more about parity violation.

Pauli asks which of Touschek's papers he could read. He writes about Leiden's paper on Gorter's experiments with orientated 58 co-nuclear spins which are in good agreement with the two-component theory.

Pauli replies to Heisenberg's letter of 27 February. He thinks that understanding between him and Heisenberg may be impossible, because he regards Heisenberg's calculations and interpretation as "wishful thinking". There is a discussion of the parity problem.

Pauli makes a comment on Fierz's letter. He writes that equations which cannot be derived from a variation principle must fail in the end, both in the mechanics of points and in classical field theory. He speaks about a book by Jordan and he speculates on the origin of life. Pauli suspects that its first beginnings are non-reproductive phenomena like Jung's "synchronic" phenomena.

Heisenberg makes two remarks on Pauli's questions: 1) about complex eigenvalues of the system N+2$\Theta$, 2) about potentials of forces between elementary particles.

Pauli writes on the recent experiments by Gorter and by Frauenfelder. He talks about a theoretical paper by Touschek and suggests to Fierz that he publishes his work on the isomorphism of the Majorana-theory theory.

Pauli makes technical arrangements in connection with his impending visit to London. He criticises the title of Salam's paper "Universal Fermi-interaction". He says that theoreticians should never use the word "universal".

Pauli makes detailed comments on a paper by Salam which on the whole is regarded by Pauli as an important step forwards.