D O C S . 2 0 8 , 2 0 9 D E C E M B E R 1 9 1 9 1 7 9 does you in for no reason at all! Talk to them both sometime, when you see them again. No mixed marriages are any good (Anna says: oh!)[13] Cordial regards, also to Anna, with whom I have made peace again,[14] from your Albert. 208. To Willem de Sitter Berlin, 12 December 1919 Dear de Sitter, Cordial thanks for your letter[1] from the magnificent high-lying valley up there, which will, I hope, return you and Mr. Fokker to full health very soon.[2] The out- come of the English expeditions pleased me very much and more so the friendly behavior of our English colleagues toward me, despite my still being a half- Boche.[3] I already entrusted translation of my little book to Mr. Lawson, since he was the first to approach me about the matter.[4] So the English publishers you mentioned should perhaps turn to him. (Addr.: R. W. Lawson, Physics Institute of the Univer- sity of Sheffield.) I do not consider an edition of my scientific papers appropriate, but certainly publication of my lectures on relativity, which must first be written down, however.[5] I do not think as pessimistically as you do about detection of the redshift.[6] In the line displacement between the Sun’s center and the solar limb, as well as in pho- tometric analysis of the line exposures, there are ways of separating asymmetric line broadenings from the gravitational effect.[7] In addition, the shift is so signifi- cant in giant stars and B-stars that it probably would be difficult to trace the shift to a secondary cause, particularly if the results obtained from different lines are con- sistent with one another.[8] With cordial regards to you and the Fokker couple[9] and best wishes for your health, yours, A. Einstein. 209. To Pieter Zeeman Berlin, 13 December 1919 Highly esteemed Colleague, Many thanks for forwarding your two papers on the [Fresnel] dragging coeffi- cient for solid bodies.[1] The derivation of the latter from the kinematics of the