Fundamental Law of Electrical Action. 371 



Of these, only three are independent. 

 It is easy to see that 



d 2 x 

 m c 2 [w 2 Q. u + ">3&13 + ^4^14] = m o c2 ~ji?> 



tor w 2 il V2 + z^Oj 3 -f w 4 H 14 =W7 2 (^ =^-j 



dfo?x _ d 2 x 



ds d* 2 ' 



for w 2 + zr 2 2 -f M? 3 2 + zc 4 2 = — 1, .'. the first term =0. 



The system of equations (17') are thus practically identical 

 with the equations (17), but for practical purposes this form 

 may be more convenient than the Minkowskian form. 



The six- vector O may be styled as the " acceleration " 

 six-vector, (12 2 3, O31, fli 2 ) being connected with the three 

 components of rotation, and (0 14 , ll 24 , n 34 ) with the three 

 components of acceleration 



( d*x dry d 2 z\ 

 \dt\ ' ~di*' dt 2 ) 



In conclusion, I wish to express my thanks to Prof. D. N. 

 Mallik, and my friend Mr. SSatyendra Nath Basu for their 

 kind help and encouragement *. 



* The paper was communicated about two years ago, but owing to 

 irregularities of the mail service caused by the war, the publication has 

 been rather delayed. Meanwhile much work has been published on the 

 subject, especially several important papers by Crehore in the 'Physical 

 Review.' The author takes this opportunity of expressing his regret 

 that he has not been able to compare his results with those obtained by 

 Crehore and other workers. 



2D 2 



