Källén talks about his calculations on fields with indefinite metric.

Källén talks about a calculation in connection with his work on the Lee model.

Källén replies to Pauli's letter of the 2 February 1958 on the product of two or more field operators.

Bohr asks for Pauli's comments on his paper with Kramer and Slater and for suggestions on how to improve this text.

Bohr has heard that Pauli developed new thoughts on the mystic of relativity in the atom theory and is asking for some developments.

Bohr discusses Pauli's paper "Zs. Phys. : 31 (1925), pp.765" of which Pauli has sent a manuscript. The letters contains a long discussion of the electron groups and the periodic table. He also writes on fluorescence radiation.