CHRONOLOGY, JANUARY 1907-JANUARY 1908 621 1907, January 22 March 3 March 17 March 23 April 16 May 14 June 17 August 1-10 second half of August October 8 October 28 December 4 December 7 December 14 1908, early January "Theoretical Remarks on Brownian Motion" (Vol. 2, Doc. 40). "Correction to My Paper: 'Planck's Theory of Radiation etc'" (Vol. 2, Doc. 42). "On the Possibility of a New Test of the Relativity Principle" (Vol. 2, Doc. 41). Delivers lecture "On the Nature of the Movements of Microscopically Small Particles Suspended in Liquids" to NGB (Vol. 2, Doc. 43). "Comments on the Note of Mr. Paul Ehrenfest: 'The Translatory Motion of Deformable Electrons and the Area Law'" (Vol. 2, Doc. 44). "On the Inertia of Energy Required by the Relativity Principle" (Vol. 2, Doc. 45). It is in this paper that Ein- stein first uses the phrase "the equivalence of mass and energy," a discovery which he would later call "the hap- piest thought of my life." Makes first formal attempt to obtain Privatdozentur at the University of Bern. Vacations with wife and son in Lenk, canton of Bern. Publishes review of Jakob Johann Weyrauch, An Out- line of the Theory of Heat. With Numerous Examples and Applications. 2nd part (Vol. 2, Doc. 46). Receipt from the Bund of Bern for a subscription in the fourth quarter of 1907. Decision on Privatdozentur at the University of Bern is postponed until Einstein submits a unique Habilita- tionsschrift. "On the Relativity Principle and the Conclusions Drawn from It" (Vol. 2, Doc. 47). Makes discussion comment in the NGB following A. Pillichody's lecture on "Mountain Pine on the Juras- sic Moors and Their Utilization in Afforestation of Frost Hollows." Inquires about a position at the Kantonsschule Zurich. Submits a Habilitationsschrift: "Consequences for the Constitution of Radiation of the Energy Distribution Law of Black Body Radiation" to the Philosophical Faculty II of the University of Bern.