Pauli replies to the letter of Lee and Yang of 12 February. He talks about My-decay and B-particles, and about recent experiments on parity non-conservation.

Pauli plans a reconsideration of the Pauli-Fierz work (in: Z. Phys. : 106 (1937), pp.572) on the H-theorem.

Pauli writes about the question of whether n or k determines the total moment of the atom.

Pauli wants to see Landé's manuscript. He also talks about the displacement of terms in strong fields.

Pauli thanks Landé for sending him the proofs of his paper. He comments on several points. He talks about the binding of the electrons in the He-atom.

Pauli writes about electron configurations in the elements K to Cu, and about the question of clarification of the hydrogen spectrum and its analogy with a reduced X-ray spectrum.

Pauli makes more remarks about the H-atom and its spectrum.

(In continuation of a letter by Sommerfeld to Landé) Pauli says that he has studied Landé's work about interaction of circular orbits by means of the adiabate-hypothesis and that he can show a simpler way to arrive at the result.

Pauli writes about the significance of the quantum numbers.