A new paper on 'the Sommerfeld-Epstein formulation of quantum theory', an ill-founded criticism of general relativity, and plans for supporting a controversial political assassin.

Brief news of Einstein's unceasing scientific productivity: 'Yesterday I presented a little thing about the Sommerfeld-Epstein formulation of quantum theory before the thinned ranks of our Physical Society. I want to write it up in the next few days. L[evi-]Civita wrote a critical paper on gen[eral] rel[ativity]. I think however that he is wrong'. Much of the letter is taken up with discussion of how to support the Austrian physicist-turned-politician Friedrich Adler, who in December 1916 had assassinated the minister-president, Karl von Stürgkh: Einstein discusses whether a petition should be organised, and suggests terms in which Adler might be praised as a teacher, noting for Besso's personal information that Adler is 'a rather sterile rabbinical mind, obstinate ... ultra-selfless ... A real martyr-type'; he recalls when (in 1909) they were both competing for a single post at the University of Zurich Adler had so praised Einstein's qualities that he had made his own appointment impossible. Einstein has just received a manuscript from Adler about relativity, which presents 'with the conviction of the prophet quite worthless subtleties', so that Einstein is at a loss how to respond. Einstein is delighted by a letter from his eldest son, Hans Albert, which bursts with 'Lebensfreude', the signs of the happy influence of life in Zurich; they may take a holiday together in the summer.