3 7 0 D O C U M E N T S 3 9 7 , 3 9 8 F E B R U A R Y 1 9 2 9 397. From Chaim Weizmann [Ruthin Castle, North Wales,] 4 February 1929 Dear Professor, After I returned to Berlin I felt very poorly, and on the doctor’s advice I have come here. It is a kind of clinic-sanatorium, and I’ve been in bed here for two weeks. I’m suffering from exhaustion, both physical and spiritual.[1] I don’t yet know how long I shall remain here—I have to get a little stronger. The wonderful occasion for this letter is your splendid article that appeared in today’s Times.[2] For the first time, I read a clear summary of the great facts that you have done so much to bring to light. It is at the same time a history of the revolution with you as its leader. Even for a half- or quarter-educated person like me, it is fairly comprehen- sible. However, I got stuck when I came to the four-dimensional (Riemannian) ge- ometry. Could you kindly recommend something to read in this area? I hope your health is good and that your new work is not accompanied by too much stress. Regarding my plans, I’m not yet at all sure, but I shall write to you when I’m feeling better. I look forward with the greatest interest to your further ar- ticles. Best wishes, yours truly, Ch. Weizmann Kind regards to your wife![3] 398. To Emanuel Libman Berlin, 6 February 1929 Dear Professor Libman, The external occasion for these lines is the need to thank you for the fine badges of Pascal.[1] The young doctor who brought them to me made an excellent impres- sion on me. He will certainly become an ornament of Jerusalem.[2] Both my wife and I are in very good health. Neither of us really has complaints any longer. In my case, the weakness in the legs has also decreased again, and my capacity for intellectual work is quite satisfactory.[3] The trip back from Scharbeutz confirmed your opinion that Berlin’s dry climate is much better for patients with heart conditions than the damper climate of Scharbeutz. The lighter precipitation of water through the skin and lungs is proba- bly a factor.