Lopes writes about the derivation of the interaction operators by the perturbation method, with special reference to Schwinger's results.

Lopes replies to Pauli's letter of 25 July, with special reference to two questions put by Pauli : 1) Use of the angular momentum integral for the reduction of the rigorous wave equations. 2) The problem of an additional term giving a contribution to the quadrupol moment.

Lopes reports on his investigation of the scattering of fast netrons by protons in the strong coupling meson theory.

Lopes writes about the interaction energy of two heavy particles in the pseudoscalar meson theory, with reference to calculations by Kemmer.

Lopes reports on his investigation of the angular distribution of high energy neutrons by protons in the pseudoscalar theory with a strong coupling.

Jauch is concerned with Pauli's remark that the integral operator of Lopes is not Hermitian. Jauch gives the correct development.

Gürsey gives a detailed view on the work he has done in the past month in elementary particles physics and announces a paper.

Einstein discusses the difference between his and Pauli's view on the significance of the psi-function. If this function does not supply a complete description of the state of a single system, one must look for such a complete description to which the real laws of nature must be related.

Dyson writes about the renormailzed field theory and on Pauli's problem of "ghosts".

All seven letters deal with Bohm's attempt to restore the deterministic picture by means of his hidden parameters, and with the connection between his ideas and de Broglie's conception.