Pauli writes about the interchange relations in the meson theory of the vacuum.

This letter contains another mathematical question in connection with an equation in de Broglies's theory which Pauli wants to criticize in his report to the Solvay-congress.

Pauli writes about the mathematics of hyper-complex numbers and the application for the case of higher spin.

This letter contains more calculations with hyper-complex numbers and applications to systems of particles with given spin.

Pauli takes an interest in Jauch's scientific development and hopes to find a position for him. He writes of his own work with Fierz. He hopes to succeed in getting rid of the spinor-calculus.

Pauli urges Jauch to take his final examination so that he could come to Zürich if Fierz goes to Basel.

About the postponement of the Zurich congress.

Pauli discusses technicalities of Jauch's possible trip to Switzerland next spring. He writes of his own work on a theory of particles with arbitrary spin. He suggests that Jauch should study meson theory.

Pauli asks personal questions in connection with the war. He makes remarks on Heisenberg's fear of continuing his correspondence with Pauli for political reasonsnd writes about the mathematical treatment of particles with higher spin.

Pauli hopes that in spite of all the difficulties caused by the war, Jauch will accept the position as assistant in Zürich.