L I S T O F T E X T S x i x 151. To Betty Neumann, 13 November 1923 152. “On an Obvious Hypothesis about the Origin of the Geomagnetic Field and Its Experimental Refutation,” before 15 November 1923 “Über eine naheliegende Hypothese betreffend die Ursache des erdmagnetischen Feldes und deren experimentelle Widerlegung” 153. From Jakob Grommer, 16 November 1923 154. From Emil Warburg, 16 November 1923 155. From Jakob Grommer, 17 November 1923 156. From Peter Pringsheim, 17 November 1923 157. From Max Planck, 18 November 1923 158. To Emil and Elisabeth Warburg, 20 November 1923 159. To Hans Albert and Eduard Einstein, 24 November 1923 160. To Elsa Einstein, 27 November 1923 161. To Betty Neumann, 27 November 1923 162. From Robert A. Millikan, 27 November 1923 163. From Théophile de Donder, 30 November 1923 164. From Gustav Stresemann, 30 November 1923 165. To Elsa and Ilse Einstein, 3 December 1923 166. To Théophile de Donder, 4 December 1923 167. To Betty Neumann, 4 December 1923 168. From Veniamin F. Kagan, 4 December 1923 169. From Albert A. Michelson, 5 December 1923 170. “Does Field Theory Offer Possibilities for the Solution of the Quantum Problem?,” before 6 December 1923 “Bietet die Feldtheorie Möglichkeiten für die Lösung des Quantenproblems?” Preußische Akademie der Wissenschaften (Berlin). Physikalisch- mathematische Klasse. Sitzungsberichte (1923) 171. To Max Planck, 6 December 1923 172. From Hermann Anschütz-Kaempfe, 6 December 1923 173. From Jakob Grommer, 6 December 1923 174. From Hans Mühsam, 9 December 1923 175. From Théophile de Donder, 10 December 1923 176. To Elsa Einstein, 11 December 1923 177. Acceptance Speech on Being Awarded a Gold Medal, 13 December 1923 Nederlandsch Tijdschrift voor Geneeskunde 68 (1924)