4 5 0 D O C . 5 2 2 U N I F I E D F I E L D T H E O R Y [ F R A G M E N T ] 522. Unified Field Theory [Fragment] [10 May 1929][1] fulfilled, which, together with the symmetric system of equations are certainly too few equations to permit a complete determination of the field. One can readily con- vince oneself of this, e.g., by carrying out an exact or an approximate treatment of the spherically symmetrical case. A correct consideration of the limiting case is apparently the following: Along with , not only but also approach zero, and in fact (in the limit) pro- portionally to . We make use of the identity … (52) which can be obtained from (37) after raising the index  there. Owing to (47), this can be replaced by … (52a) If we carry out the operation on (46a), we obtain the following equation, taking (52a) into account: … (52b)  3 S /  S    3 D  G 2     0 G 2  /  G 2       +     D  H 2   1 2 S /  +   0  D   2 D  H 2      3 D  f    + 0 =