1 6 6 D O C U M E N T 1 9 1 M A Y 1 9 2 2 I made a monumental blunder myself a while ago (experiment about light emis- sion with canal rays).[8] But be consoled. Only death can keep one safe from blun- dering. Bohr’s papers fill me with great admiration for the steady instinct that governs them. It is very nice that you are working on helium. The experiment by Stern and Gerlach is the most interesting at the present time, though.[9] The atoms’ orientations without collisions cannot be explained by radiation (according to cur- rent methods of considering the problem). By rights, an orientation ought to persist longer than 100 years. Ehrenfest and I did a brief calculation of it.[10] Rubens con- siders the experimental finding absolutely secure.[11] Do soon dispose of the money for purchasing the X-ray apparatus! Why is it tak- ing so long?[12] Cordial regards to all of you from your Einstein. 191. From Paul Ehrenfest [Leyden,] 16 May 1922 Dear Einstein, All of us miss you very, very much!![1] – — . — I had to settle a few things for you after your departure: 1. One Public Universit. Rotterdam—You had left and would return only late next spring 1923. 2. Enclosed letter from Prof. J. van Baren.[2] I answered: You had left, would not be going to Java. But would forward letter to you as you might possibly satisfy his request indi- rectly. (I was thinking via Freundlich[3] or the like.)—He deserves this help because he did much work on these things. 3. Dismissal of a (very unappealing) Zionist-lectures organizer. (“Einstein is in Holland exclusively for specific advice on physics.”) 4. One newspaper photographer. — . — I hope very much that now you’ll finally get to know my dear, dear Joffe.[4] He is a very fine physicist and person. You’ll enjoy him in every respect. Together with my wife, you, and Bohr, he is my closest friend and maybe no man has shown more love for me than he.– The danger that the two of you will while away your time together with “newspaper-feuilleton” chit-chat is enormous. — . — — . — I’m afraid that I’m not going to be able to finish up our note about the Stern-Ger- lach experiment by the next academy meeting.[5] – Breit propounded the following