Pauli writes about the success of the hypothesis of the magnetic electron. He writes about the connection of Schrödinger's equation with quantum mechanics. He comments on the conclusions of Heitler's paper on statistics. He writes about the second order Stark effect.

Pauli replies to Schrödinger's letter of the 18th May 1926. He writes about the connection between quantum mechanics and Schrödinger's wave mechanics. He talks about the transition to classical quantum theory for large quantum numbers. He comments on volume integral and on the higher rotational states of the electron.

Pauli discovers a mistake in Uhlenbeck's calculation of a certain integral.

Heisenberg thanks Pauli for his book (Hand-Buch-Article). He writes against Schrödinger's conception which throws all quantum theoretical phenomena over board and about Wien's agreement with Schrödinger's attitude.

Heisenberg expresses his comments and doubts about Pauli's statistical theory. He has more throughts about velocity-position indeterminacy. He writes about his ideas on ferromagnetism and about intensity change in band spectra.

Heisenberg replies to some questions from Pauli.

Pauli talks about his work with Heisenberg on field theory. He makes remarks on Dirac's electron theory.