DOCUMENT 344 JANUARY 1912 395 ten verdunkelt.[5] In Berlin haben sie nun noch gefunden, dass sich gasförmi- ger Wasserstoff bei genügend tiefen Temperaturen wie ein einatomiges Gas verhält.[6] Ich habe eine Theorie dazu gemacht, deren Basis jedoch nicht si- cher ist.[7] Ich werde Ihnen dann davon erzählen. Die Columbia Universität in New York hat mich für nächsten Herbst eingeladen zum Vortragen. Ich gehe aber nicht hin.[8] Nach Wien gehe ich auch nicht. Ich mag diese öffentliche Vortragerei nicht.[9] Abraham hat meine Gravitationssache zu einer geschlos- senen Theorie ergänzt, aber bedenkliche Denkfehler dabei gemacht, sodass die Sache wohl unrichtig ist.[10] Das kommt davon, wenn man formal operiert, ohne dabei physikalisch zu denken! Seien Sie von Herzen gegrüsst von Ihrem Einstein Ich freue mich sehr, bis wir uns wiedersehen. Vielleicht zeigt sich vor dem Sommer wieder einmal ein braver Patient in Prags Nähe![11] Beste Grüsse von Haus zu Haus! ALS (Estate of Heinrich Zangger, Zurich). [39 644]. Only a fragment has been found. [1]Date provided by Helen Dukas, probably on the strength of information from the Zangger Estate. [2]Peter Debye had been advanced from extraordinary professor to full professor at the Uni- versity of Zurich two weeks earlier (see Aus dem Protokoll des Regierungsrates 1912, no. 54, 11 January 1912, SzZSa, U 110 b .2 (48)). [3]In fact, Debye was formally appointed Professor of Mathematical Physics and Theoreti- cal Mechanics at the University of Utrecht on 3 February (see Nederlandsche Staatscourant, 4/5 February 1912, p. [2]). In a letter, dated 23 January, Einstein had been informed of his own nomination to a position at the ETH in Zurich (see Doc. 341). [4]See Einstein 1912b (Vol. 4, Doc. 2). See also Vol. 4, the editorial note, "Einstein on the Law of Photochemical Equivalence," for a discussion. [5]See Doc. 313, note 7, for information on Einstein's paper on residual rays. He had argued that the two observed maxima were in fact one wide resonance peak (see Doc. 331). The fact that new experimental data found by Rubens's collaborator H. Hollnagel at first seemed to con- firm the existence of the two peaks is mentioned in Rubens 1913. This paper presents further experimental results, however, from which it is concluded that selective absorption by water vapor in the air had been responsible for the observation of two maxima. [6]See Eucken 1912. [7]A year later Einstein and Otto Stern submitted a paper in which a theoretical explanation is given for Eucken's results (see Einstein and Stern 1913 [Vol. 4, Doc. 11]). See Vol. 4, the editorial note, "Einstein and Stern on Zero-Point Energy" for a discussion. [8]The offer is made in Doc. 337, and Einstein declines it in Doc. 346. [9]An invitation was extended to Einstein to lecture in Vienna at the end of January (see Doc. 326, note 1). Two lectures are mentioned in Doc. 354. [10]See the preceding document, note 3 for more on the controversy between Einstein and Max Abraham. [11]On traveling to Prague in June (see Doc. 268) and again in September of the previous year (see Doc. 286), Zangger, a doctor and forensic specialist, had visited a patient on at least one of those occasions (see Doc. 303).