Klein's comments on the proofs of Pauli's encyclopedia article.

A few more suggestions from Klein for changes to Pauli's encyclopedia.

Klein sends a reprint with remarks. Klein reports on his activities in Ann Arbor.

Klein's writes about his and Hilbert's view that the specific significance of Einstein's theory is to be found in its physical conception, but that its precise formulation is a purely mathematical problem. He makes further comments about relativity.

Klein writes about the paginated proofs of the article and gives more suggestions.

Kita talks about the behaviour of Heisenberg's S-function. He asks a question about the translation into Japanese of Pauli's handbook-article of 1933.

The letter contains a critical discussion of Heisenberg's quantization of non-linear wave equations.

Kemmer gives more calculations on the wave equation and makes a comparison with de Broglie's results.

Critical remarks from Kemmer about Bhabha's calculations on the neutretto-meson theory and remarks on the Bremstrahlung of the meson.

Kemmer gives a development of a convenient formalism for the wave equation, different from the usual representation of Dirac's Hamiltonian.