D O C . 1 6 8 N O V E M B E R 1 9 1 9 1 4 1 ing! I picture you with the page in hand and how the stark numbers fixed your eyes and mind with magical force, boring into your brain, and saturating your soul with certainty and gratification.[2] How cut off from the world you must have been at this emotional instant! Aren’t you most profoundly thankful to the Sun for being so good to you? And to the stars for making you jump out of your skin in such a way? The English did well and it will have to make your skeptical countrymen ac- knowledge the theory finally, after all. I know that Rutherford is happy too about it. “It’s all very interesting,” he wrote in a letter to me a few weeks ago when, con- fidentially, he told me about the result before it was made public.[3] Now it’s the spectral-line shift’s turn to acknowledge you! The letter you wrote me from Lucerne during the summer was extremely mean- ingful and valuable to me. I was very pleased by your faith in the future and the eventual success of the League of Nations. Let’s hope the great men in America aren’t quite as unscrupulous as the Prussians were and they aren’t talked into the necessity of the next genocide, between America and Japan!! I was told by what appears to me to be a well-informed source that, since the armistice, the U-boat of- ficers from Germany have been selling themselves in droves to the Japanese Navy.[4] That’s a real killer business, where all excuse for patriotic excess falls away!! Lately, I learned much from a little book by Tagore, Nationalism,[5] where these questions are elucidated from the Indian point of view, whereby I got an ink- ling about how much we are chained to old and probably wrong traditions, and whereby I got a better outlook on Ehrenfest’s desperate quarrel with all things state- ordained and rigidly organized. I hope you can be content with your mother’s state of health and with your own disposition.[6] When we heard of your sojourn in Leyden, we were very sorry that we could not be there as well. For you, I hope, it was a pleasurable time and that you enjoyed being at the Academy in Amsterdam.[7] I very much look forward to the papers you promised to forward to me from Ber- lin. Please send them to me very soon. Just today they would have been very wel- come, as I have finally finished another grind in which I had been immersed up to my ears, to the exclusion of being able to do anything else. Now I would like to catch up on the backlog in other fields. And naturally, gravitation problems and es- pecially your viable electron attract me particularly strongly.[8] I was occupied with an improvement of Kroo’s theory about the inner electron rings (Phys. Zschr. XIX, 307, 1918),[9] since, for interactions among electrons he simply applied the electrostatic one. And yet, according to the theory of electrons, at the high electron velocities in question and at small distances, additional terms should be taken into account that absolutely cannot be neglected if one allows for relativity corrections. If one wants to calculate with the third relativity correction,