Pp. 639-641 in Annalen der Physik, Vierte Folge, Band 18, Heft 3, No. 13. Whole volume offered. (8vo) 9x5¾, original wrappers. First Appearance, Journal Issue.

First appearance of Einstein's first proof of the relation that would later be stated in the formula e=mc2 and one of the most important papers dating from 1905, Einstein's "annus mirabilis". "A few months after first publishing the theory of relativity, Einstein discovered something that particularly intrigued him; the relation between inertial mass and energy...Einstein argued that, as a consequence of the relativity principle, inertial mass is associated with all forms of energy. He was only able to establish this result for a process involving the emission of electromagnetic radiation by a system, but argued that the result is independent of the mechanism by which the system loses energy. In addition, he was only able to show that a change in energy is associated with a change in inertial mass equal to the change in energy divided by the speed of light squared." (Stachel, Einstein's Miraculous Year, pp.117-118).