MAGNETO-OPTIC PHENOMENA OP IRON, NICKEL, AND COBALT. 
91 
(/, g, h) and (/', g', h') are the vectors T)' of Larmor’s theory (‘ Phil. Trans.,’ 1895 ), 
namely {/. g, h) is the displacement involved in the aether strain, and {/', g h') that 
involved in the polarisation of the matter. 
Fundamental Equations. 
5 . It being as usual assumed that for oscillations so rapid as those of light the 
effective magnetic permeability is unity, the fundamental equations of the theoiy 
are as follows :— 
(i.) The two circuital relations 
dc 
Fj 
dh 
— y =r 477?/., 
dz 
I 
1 
dc 
dx 
— 477?;, 
dh 
dx 
11 
e 1 
1 
1 
4:7710 . 
. (1), 
da 
dr 
dll 
_ dh 
dQ 
dc 
. (2). 
E 
I "^5 
1 
II 
1 
dz^ 
dx 
~ dt ’ 
dx 
dy 
dt 
(ii.) The equations of the current 
U — aP-j- g^Q — g^R + 
V =: aQ F ~ 9 sP + ~ y .( 3 ), 
fth" 
IV = o-ll + g.^? - -f — 
where the vector {g^, g^, g^) represents the Hall effect. 
(iii.) The displacement relations, and the elastic relations between electromotive 
foi’ce and the corresponding polarisation, viz., 
f" g'^g^ g\ h" = h + h'. 
■f P’ 9 — Q, 
and 
TttC" 
f' = 
g ^ 
h' = 
• ( 4 ), 
• ( 5 ), 
K - 1 
TttC" 
P+h 
dQ 
^ cU 
h. 
dt 
K - 1 ,a! 
^ Q + ''> * 
1 dV 
^ A 
^ dt ' 
7 
■ (fi). 
the vector (6j, hc^, 63) representing, in transparent matter, the whole magneto-optic 
effect. 
