Pauli gives additional remarks to a paper by S T Epstein on self-energy. He comments on the physical significance of auxiliary particles. The letter mentions his work on D-factors, appearing in connection with the Lambshift and the magnetic moment of the electron.

Pauli mainly writes on positions offered to younger colleagues.

Pauli gives his reactions to Schwinger's work, news about Heitler and Staub and lecture plans.

Pauli discusses about a paper by Weibel.

Pauli talks about the sign of vacuum polarization. He says that the vacuum polarization charged auxiliary particles must be introduced (positive and negative, zero spin).

Pauli refers to a discussion he had with Born, Klein and Kirkwood. He also describes his own objections to a talk given by Born during a conference in Florence (properties of a certain operator). The letter touches briefly on other matters, including Born's theory of reciprocity.

Pauli was glad to have Bohr's recent letter and was particularly glad to hear that part II of the joint paper by Bohr and Rosenfeld made such good progress. However, he goes on to say that "there is one important point regarding the consequences of the quantum-electrodynamical formalism for charge- (and current-) fluctuations (positron-theory) on which he cannot agree with you: according to my opinion Heisenberg was entirely right in his claim of unsharp limitations of either the space or the time domain in which the charge (or current) fluctuation is considered in contrast to the case of energy (and momentum) fluctuation of the radiation (where a sharp limitation of the space-time region is sufficient to guarantee a finite value of the square of the mean value of the field strenght over this domain)". The letter also contains other scientific problems.

Pauli writes on Schwinger's impending visit to Zürich.