Pauli makes a short acknowledgement of Heisenberg's letter of the 12 March.

Pauli gives comments on a new manuscript by Heisenberg which is valued very positively by Pauli.

Pauli writes about a work by Uhlenbeck and Kahn. Pauli uses the V D Waals state equation in order to show that the thermodynamical considerations of Uhlenbeck cannot be correct. He hopes to come again to Holland. He writes about Heisenberg's difficulties with Stark and the Gestapo, and that Heisenberg requests that physicists abroad should support him. He writes about the necessity of jobs for dissmissed Viennese physicists.

Heisenberg hopes that "Nature" will reply to Stark's article. He talks about the possible reasons for the asymmetry of Beta-ray-spectra.

Pauli discusses the problem of scattering of mesons and protons. He talks about the preparation for the next Solvay congress.

Pauli writes again on the question concerning de Broglie 's equation.