Heisenberg writes on the difficulties of the phase problem in radiation theory, and on a Hund's paradoxon about optically left- and right-rotating substances and its solution.

Heisenberg writes about Pauli's suggestions for the quantum-theoretical relations between electrical and magnetic field strengths. He writes also about Pauli's criticism of Dirac's paper and discussions with Bohr about his thought experiments.

Heisenberg writes about his discussions with Bohr on the "$\Gamma$-ray-microscope". He makes some remarks on Pauli's electrodynamical considerations, on the Hamiltonian interaction function between radiation and matter and on a paper by Darwin about Heisenberg's and Jordan's formulae.

Heisenberg writes about the Dirac-Jordan theory and Heisenberg's criticism of Bohr's objections.