Pauli writes more about the history of the neutrino. He makes critical remarks on Wu's historical paper.

Pauli writes about Miss Meitner's older contributions to the beta-decay problems, mentioned in Pauli's German paper on the neutrino's history. He makes a short condensation of his paper, beginning with Chadwick's paper of 1914 and ending with Meitner's and Orthmann's paper of 1930. Pauli comments on the situation after Chadwick's discovery of the neutron (1932).

Pauli thanks for Yank's and Feldman's paper. He writes about Glauber's calculations.

Pauli invites Yang to a lecture in Zürich. He comments on an interpretation of a recent experiment by Garvin and Ledermann and by Deutsch and Frauenfelder on parity violation. He critizices two-component theory. He writes of his own views on T-invariance and conservation of Lepton-Charge. Only the development of quantized field theories will provide answers to the deeper questions.

This is a supplement to the letter of the 26th May 1957. Pauli comments on a theoretical paper by Preston (Birmingham) which fits well with Pauli's critical attitude towards the two-component theory. He writes about Preston's proposal to give up the conservation of leptons. Pauli thinks that T-invariance seems still to be possible.

Pauli replies to Yang's and Lee's letter of the 12th February 1957. He writes about several experimental checks which should be made: 1) On the equality of beta-decay life times in meteorites and on earth, 2) For CPT invariance (equality of the mass of particles and anti-particles). He comments on a paper by Wheatley, Tolhoek et. al., with oriented Co6o nuclear spins.

Pauli compares some of Yang's equations with his own results.

Pauli comments on a paper by Salam and his B-field. He writes about the open question whether the rest mass of the B-particles is zero. He writes about the conservation of lepton charge, two-component theory and CP or T symmetry. He writes about Lüders' and Pauli's theorem, and Schwinger's previous theorem. He makes remarks on his calculations last autumn, connected with the "Pruett-factor".