Theory of Radiation, 55 



As explained in my previous paper F x excludes all the 

 irregular interatomic field; (43) gives 



(p 2 /c 2 + tc 2 -7i 2 + 2ink)F 1 + 47rpu/c=0. . . (44) 



Let d^S represent an element or area parallel to the wave 

 front, dz an element of length perpendicular to it. dz though 

 not infinitesimal is very small compared with the wave- 

 length 



{p 2 /c 2 + P - n 2 4- Zink) F x dS dz + lire' l j* pu dSdz=0. 



Or since we are concerned only with the disturbance due to 

 the passage of the wave 



(p 2 /c 2 + k 2 -n 2 + 2ink)F l d& dz + ±TTc- l §$pu d$ dz = 0. (45) 



Evidently the average value of SfpudSdz is propor- 

 tional to dS dz. 



It may be shown by the methods of this article that (45) 

 is equivalent to two equations of the form 



(p 2 /c 2 + k 2 - n 2 + %nlt)F x + ® xy F x + 3>i2^i = 

 (y / C 2 + p _ n 2 + 2i n k) G v + ^ 2l F, + <D 22 G l 



I do not here consider further these results. 



\-°o}- < 46 > 



§ 7. Theory of Induced Magnetization. 



I end by demonstrating the inadequacy of the classical 

 dynamics to explain magnetic phenomena. Suppose the 

 only disturbing force a steady magnetic field. Then 



^=0, ro=l/2... x>, . . . (47) 



&*N= f'~ (dK)dt, (48) 



It follows that ^ N ) = -A^N,by(30).. . (49) 



dH __ r = K d_(d®\ m _ r ? K d< & d( lr 

 dt r -i dt\du r ) ' r =i dq r dt 



_ d /^ d<&\ r ^ K /d<f> dqr d(f> du r \ 

 dt\ r diir) r= i\dq r dt du r dt /' 



dH d /_-< d<& ,\ fd6\ /KA x 



l-~ I denotes the differential of </> with respect to the 



\dt /exp. 



time, in so far as that occurs explicitly. 



<!>= % Otm (f>m. 



