482 BARON VON WREDE ON THE ABSORPTION OF LIGHT. 
= r™—*) aT sin Qa (4 = a vee 
— eos 2n( ¢— =) sinn 72°]. 
r r 
The velocity of undulation U, which the particle of zther acquires 
through the action of the collective systems of waves of light, must 
now be: 
Sut ty + Uy + U, + Uy, + 100 & 
n 
and therefore 
U=a(1—r)? { sin Qa oe = [a+ 7? cos nae 
2 
+ rto0s2.2m 2° + ..7 "osm. 2m 2 
_— cosa (¢—2) [sine x 2? 
A Xr 
an Pee oe 28 ee eek nine wee 
If we now assume 
a(1—r)? [2 + 72 cos 27 20 cos 2.27 28 
Gs 
+... ign hee ] =A. cosi 
PAC niet kg sin 20 20 + résin 2.2450 
: As bie 7) 
+ ..9r "sinn 225" | = A.sini 
U=A.sin] 2x (¢~) -é] wie 
The system of waves of light thence resulting will be quite of the same 
nature as the original, only that it has a different intensity and a different 
position. 
we shall have 
(To be continued.) 
