i dot Owe doa òNeotoe 
Tao — wb Ne ot Ort > Ive <= = oF Ve + 1E oe SS 1yb> 2 org 
te OE | Ò xe ue 
do? Ow? do! dNeobge 
— wtNe| 9 —14rl4) S | we — e LS Os + swt —— ioe 
ii ue NS Ome Ò ae ane 
Ow? Owe do do 
——1 Neot 0° — Neo’ So Nel ot we —-- 04 we : 
g N Q ke 
Oat at ane 
We recognize the simultaneous displacements (6.2), and find 
0 Nests¢ 0 Nes? se 
fab = wh) Nese tt — wa }Nesh —1 S 
Ome 02‘ 
LN ES Ow? LANE Owe LN ds a) 
== est se SS es sc - 5 (1 — 
Owe cS da:\4) da 
8. Taking 5 —= 4, some terms vanish, and we get 
0 Nest se 
Oare : 
Remembering what has been found about the polarization in 
(6.3), we at once see that 74 (a= 1, 2,3) are the components of 
the polarization. Thus the polarization is no 4-dimensional vector: 
its components are the space-time-components of a tensor. 
When neither a nor 6 have the value 4, then the part of 7 
containing the polarization : 
0 Nests¢ 
| — wt 
Owe 
Tt = Nest — 4 5 (c) 
0 Nes? sc 
Ox? 
is nothing else but a component of the well known RÖNTGEN-vector, 
which in three-dimensional analysis is written [p.w], where p and 
ware the three-dimensional polarization and velocity vectors. We see 
that in our tensor the components of polarization are always accom- 
panied by the components of the corresponding RontTeEuN-vector. 
we {Nest — 4E Nest — 4 3 
9. In another part of Te (a44, bd), viz. 
ds? dst 
emu) = 4 Ne| st — sb ' 
da\4) de 
we recognize the components of magnetization. 
The remaining part however: 
On 
— 4 Nest  (c) se 5 
vb GE 
- + 4 Net 3 (Os. 
& Ow c 
indicates the existence of a new effect. It is of the second order and 
