Pauli asks if Bohr could go through Heisenberg's manuscript dealing with a new conception of the Zeeman-effect.

The letter talks about Pauli's visit to Copenhagen in April and about the progress he made in the kinetic of heat conduction in solids.

Pauli writes about electron configurations in the elements K to Cu, and about the question of clarification of the hydrogen spectrum and its analogy with a reduced X-ray spectrum.

Pauli makes more remarks about the H-atom and its spectrum.

Pauli's interpretation of intercombination lines and the application of his model to several cases (Zeeman-effect). He expresses hope for the progress of physics through Heisenberg's mechanics.

Bohr thanks Bohr for his letter of the 25th September.

Pauli writes about mathematical contributions to the quantum-mechanical calculus.

Pauli makes some objections to Thomas' derivation of the missing factor in magnetic interaction of the spinning electron. He is opposed to its publication.

Pauli describes the theoretical tasks if the spinning electron is correct. He criticizes Thomas' relativistic derivation, published in: Nature : 117 (1926), 514.

Pauli capitulates to Bohr and Thomas and suggests some improvements in Thomas' manuscript. He also plans to visit Copenhagen. At the end of the letter Pauli writes to Kramers.