Heisenberg writes on stability considerations in H$_{2}$ and about failure of the energy-calculations for He.

Heisenberg encloses a manuscript discussing certain properties of the propagation function of the non-linear wave equation. He asks for Pauli's opinion.

Heisenberg writes on excitation times and line widths.

Heisenberg writes about the quantum theory of the Zeeman effect. He makes a comparison with a paper by Bohr.

Heisenberg replies to Pauli's letter about quantum numbers. He also writes on Pauli's use of the summation principle for the calculation of Lande's g value and on the difficulties of the doublet-theory.

Heisenberg replies to Pauli's lettter and asks about the behaviour of the operator $\chi$ on the light cone.