Heisenberg has some considerations proving the near relation between his work and the Lee-model.

Heisenberg makes a tentative reply to Pauli's question about dipole ghosts.

Heisenberg talks about objections to Pauli's argument as regards the proof of the unitary character of the S-matrix.

Heisenberg talks about a reviewed discussion of the mathematical results for the three sectors V, N+2$\Theta$, N+V.

Heisenberg summarizes the mathematical results as regards dipole ghosts on which he ana Pauli agree.

Heisenberg replies to Pauli's arguments about the splitting of the dipole ghost by an interaction energy, and about the problem of causability in connection with his theory.

Heisenberg makes two remarks on Pauli's questions: 1) about complex eigenvalues of the system N+2$\Theta$, 2) about potentials of forces between elementary particles.

Heisenberg explains that the unitarity of the o-matrix and the positive sign of the norm of stationary states in the Hilbert-space I are two aspects of the same fact.

Heisenberg thanks Pauli for his preprint on the conservation of leptonic charge. He sends by the same mail a first blueprint of the Lee model paper. He writes about further progress in his calculations.

Heisenberg states the points on which he and Pauli agree. He asks Pauli's view on several other points.