Pauli writes on the basis of his Princeton experience to suggest a new approach to problems like that dealt with in Fermi's theory.

The letter asks a question about a model for neutrinos with Delta-like interaction.

Pauli replies to Heisenberg's letter of 26th November. He writes about consideration of the possibility of introducing the lattice method for the solution of the impact problem.

Pauli makes some remarks on Heisenberg's latest results, especially properties of the Hamilton-function. He gives some comments on nuclear theory, especially the role of the neutrino-field for nuclear forces.

Pauli makes a short report about his research program and about pair creation.

Pauli comments on recent work on cosmic rays (Bhabha and Heitler), and on the experimental confirmation of Bethe-Heitler's brems-formula for fast electrons. He talks on the quantization of waves.

Pauli congratulates Heisenberg on his engagement.

Pauli makes further remarks about the necessity of a universal length.

Pauli writes mainly about books. He recommends C Morgan's "Sparkenbroke" whose religious approach is reminiscent of gnostic ideas.

Pauli thanks Kemmer for his letter and his satisfactory results.