The letter gives a short evaluation of the political situation, in connection with Kemmer's doubts about England. He replies to some physics points raised by Kemmer.

Pauli asks questions about the algebraic properties of certain relations and makes some remarks about spin operator.

The letter contains detailed discussions of systems of hyper-complex numbers

Addition to the former letter.

Pauli wants to continue his work with Kemmer on systems of hyper-complex numbers. He asks questions about application of quantum theory (perturbation) and on scattering of neutral mesons.

Pauli continues with his calculations with hyper-complex numbers. He adds some remarks on "neutretto"-scattering and the theory of mesons.

A short addendum to the last letter.

He agrees with Keller's paper on "Hidden variables" in quantum theory (P.R.89, 1040) as regards the role of probability in Bohm's interpretation and refers to his own paper in the anniversary volume (60th birthday) for L. the Broglie same subject.

Pauli writes about some free time he spent with A. Thellung, and about his (Pauli's) relationship with the Kramers.

Pauli agrees with Källén about an error in Thirring's paper. The question now is whether Hurst's paper is correct.