The letter describes a problem of classical theory of harmonics. It talks about Pauli's calculations on Bohr's He-Model. He looks forward to his work in Copenhagen.

Pauli speaks about his calculations on the thermic equilibrium between radiation and free electrons, about scientific life in Hamburg and about the German translation of Bohr's Nobel-lecture.

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.

In this reply to a letter from Pauli, Bohr develops his exclusion principle and attempts to explain this rule in the framework of the electronic orbit model.

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

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.

Pauli suggests postponing his visit to Copenhagen. He talks about his work on quantum electrodynamics and makes a criticism of Klein's paper in the Zs. f. Phys. Pauli thinks that Klein is not ready to see the use of multidimensional spaces as an inherent part of the approach of quantum phenomena.

This letter is a reply to Bohr's letter of the 15th July. Pauli writes about Jordan's manuscript. He criticises its last paragraph where Jordan does not distinguish between the particles (de Broglie field) and the electromagnetic field. He talks about Jordan's and his own work on radiation electrodynamics in the absence of charged particles. He also writes about a paper by de Broglie in the Journ. de Phys. which attempts to harmonize between dualism of waves and corpuscles on the one hand and complete determinism of physical events on the other hand.

Pauli talks about a paper by Holtsmark in Naturwissenschaften.

Pauli writes about his discussion with Miss Meitner on the experiments of Ellis and Wooster on Beta-decay.