Pauli is glad about the changes Bohr made in his manuscript, in particular about his explanation of complementarity. He looks forward to meeting him in Hamburg.

Pauli hopes that Kronig will accept the post of Pauli's assistant in Zürich.

Pauli writes Kronig that his appointment runs from May 1st until the end of the summer term.

Pauli asks if the last proofs of Bohr's paper are completed; if so, he would like to come to Copenhagen for some talks.

Heisenberg continues his letter on ferromagnetism.

Heisenberg replies to Pauli's questions about his letter on ferromagnetism: 1) on the magnetic moments of the atom residues, 2) the case of paramagnetism, 3) the calculation of the state-sum.

Pauli replies to a question from Bohr, whether an H-theorem can be derived from the point of view of quantum mechanics. He has made no progress in quantum electrodynamics and thinks that a completely new idea is still missing. He writes about Kronig's works and about Nature's introductory remark to Bohr's article.

The letter includes remarks on a paper by Pauli, on a second paper by himself on ferromagnetism for the Sommerfeld-Festschrift and on Dirac's theory.

Pauli gives some personal evaluations of Oppenheimer and Bloch. He also comments on Rutgers and his progress with quantum electrodynamics.

Pauli and Scherrer invite Kronig to a conference in Zürich on X-ray physics.