Darwin replies to a letter by Pauli answering that of 20-11-1927 and he discusses several features of the Stern-Gerlach effect. He writes to Pauli about Dirac's equation which is just about to be published.

Darwin warns Pauli that his forthcoming paper in the proceedings of the Royal Society contains something of an attack on Pauli, as regards the spinning electron in free space.

Born replies to a letter from Pauli and gives a clarification of his and Pauli's divergent views as regards the statistical theory of irreversible processes.