D O C U M E N T 2 5 5 A U G U S T 1 9 2 8 2 5 1 IV. For the invariant, “decoupled”[7] (+ “second”) to first approximation, a par- ticular electric solution of , is given as follows: I refer to our ear- lier calculations [8] we have first , and require for a particular solution, I can indeed set obtain the above from , which at the same time (as required) is har- monic the equations for are allowed here, owing to , , and are the same as for , thus also is al- lowed in contrast, now , for which we have used also . Then we find,due to without summation, as the particular fundamental solutions, which would appear to me, however, ow- ing to the accompanying line element, to be physically hardly reasonable, even if an arbitrary pure gravitation solution is added. V. Again, setting , must satisfy (particu- lar) according to the recipe I choose , , . I choose , then  harmonic only in the , , , , , , , thus  a 0 =  4 j  r =  a  0 =  4  t r ---- = H a a  a  a 13   4  =  4 0 = H a a  t 3 ----logr x a +  = H m a   a 0 =  a 0 = H a a  H m a  t 3 ----logr x a +  = m 1 2 3   = H m 4  0 = H 4   0 = h  a   a  H  x ------------ - = h a a  w/o sum. t 3r = h m a  a  t 3r ----- x m r x a + ------------- = h 4 a  h a 4  0 = = h 4 4  j =       x ------------ = H   v  H v  v  –   vv    = H a  a  0 H a a  H a a U a a 0 = = = = = H   v    vv    = H  v    vv    = H  v U  v +   vv    = H  v   vv H  =  a  0 =    t r = U  v   vv    H  – = H a O = H a x a H 4  2 2 t ----------- - 0 = H m a 0 = H  4  2 2 t ----------- - 0 = H 4 m  2 m 2 x ------------ - m 13  H 4 = F a 0 = F 4   vv H 4 = F 0 = F 4  2 2 t ---------- - 0 = U  v   vv  –H = U a m 0 = U  4  2 2 t ----------- - 0 = m 4 –U   mm U 4 m   mm 4 –H = =