Bohr has sent a manuscript with the preparation of his discussion remarks from Brussels to Langevin. He is sending now another copy to Pauli and he would be very glad to hear his opinion before he gets the proofs. Bohr and Rosenfeld are eagerly awaiting the promised article with Weisskopf. He need not say how pleased he was to hear that there is a possibility of a visit by Pauli to Copenhagen in Spring. Perhaps Heisenberg and Dirac will come too. Bohr's own journey to Russia should take place in the beginning of May, and Margrethe and Rosenfeld will accompany him on the journey.

Bohr is sorry not to have written for so long, but his time has been very occupied since his return from America. He says that it was nice to be at the Princeton Institute again, and it was a special pleasure to see in how quiet and dignified a manner Oppenheimer took the decision of the Atomic Energy Commission. Both he and his wife were more glad than they have been for a long time, and it has been a great encouragement to them to feel what good friends they have not only amongst the physicists but also in wide circles of the American community, for whom this unreasonable matter has been a great shock. Now he hopes that Robert will have more time for his scientific work, and he is - like the whole circle in Princeton - deeply interested in the many problems which the experiments with the elementary particles always make more contemporary. When Bohr was in Princeton they had also many discussions about the general biological and psychological questions in which also Delbrück took part. Bohr hopes that Pauli will soon come to Copenhagen and speak to the CERN group, and that his wife will come too.

Bohr asks for Pauli's comments on his paper with Kramer and Slater and for suggestions on how to improve this text.

Bohr has heard that Pauli developed new thoughts on the mystic of relativity in the atom theory and is asking for some developments.

Bohr discusses Pauli's paper "Zs. Phys. : 31 (1925), pp.765" of which Pauli has sent a manuscript. The letters contains a long discussion of the electron groups and the periodic table. He also writes on fluorescence radiation.

Bohr thanks Pauli for his beautiful paper. He wants to refer to it in a note.

Bohr discusses the "Gospel of the magnetic electron". He writes that Kramers has confirmed Pauli and Heisenberg's calculations. Bohr is still hoping for a correspondence agreement. Kramers made a guess as to the relativistic and magnetic corrections, the relevant formulae are given in the letter.

The letter encloses a paper by Jordan published in: Z. Phys. : 44 (1927), pp.473. Bohr discusses it briefly and refers also to Klein's work. Bohr has not yet finished a "small note". He refers to Pauli's visit.

Bohr has sent proofs from Holland to Berlin for "Naturwissenschaften : 16 (1928), pp.245" but he is still expecting his last proofs. He hopes to see Pauli in Copenhagen. He has enjoyed seeing Kramers and Ehrenfest in Leiden. He is preparing his opposition to Jacobsen's thesis. Klein is still in Cambridge.

Bohr encloses his paper for "Naturwissenschaften :16 (1928), pp.245" and expresses his gratitude for Pauli's help.