( 824 ) 



dl 



— = 0, I zz^ const. 



dto 



The value of the constant must be unity, because we know ah'eady 

 that, for "' = 0, / = 1. 



We are therefore led to suppose that the inflnt'nce of a trandation 

 on the diuienmms (of the .separate electrons and of a ponderah/e body 

 a.s' a ivhole) is confined to those that hart' the direction of the motion, 

 these beconiiny k times smaller than they are in the state of rest. If 

 this hypothesis is added to those we liaxe already made, we may be 

 sure that two states, the one in the moving system, the other in the 

 same system while at rest, corresponding as stated above, may both be 

 possible. Moreover, this correspondence is not limited to the electric 

 moments of tiie particles. In corresponding points that are situated 

 either in the actiier between the )>articles, or in that surrounding the 

 ponderable bodies, we shall find at cori-esponding times the same 

 vector b' and, as is easily shown, the same a ector !)'. We may sum 

 np by saying : If, in the system without translation, there is a state 

 of motion in which, at a delinite place, the components of p, ^ and 

 () are certain functions of the time, then the same system after it 

 has been put in motion (and thereby deformed) can be the seat of 

 a state of motion in which, at the corresponding j)lace, the com- 

 ponents of p'> ^' ^Jid h' are the same functions of the local time. 



There is one point which requires further consideration. Tiie values 

 of the masses ///, and m.^ having l)een deduced from the theory of 

 quasi-stationary motion, the question arises, whether we are justified 

 in reckoning with them in the case of the rapid vibrations of light. 

 Now it is found on closer examinatio]i that the motion of an electron 

 may be treated as quasi-stationary if it changes very little during 

 the time a light-wave takes to travel over a distance equal to the 

 diameter. This condition is fulfdled in optical phenomena, because 

 the diameter of an electron is extremely small in comparison with 

 the wave-length. 



§ 11. It is easily seen that the proposed theory can account for a 

 large number of facts. 



Let us take in the first place the case of a system without trans- 

 lation, in some i)arts of which we haxe continuall}' p = (), b = 0, 

 f) =: 0. Then, in the corres[)Ouding state for the moving system, we 

 shall have in corresponding parts (or, as we may say, in the same 

 l)arts of the deformed system) p' = 0, b' :rrt 0, l/=i(). These equations 

 implying •> = 0, b =: 0, ^ = 0, as is seen by (26) and (6), it appears 



