34 Law of the Induction of an Electric Current upon uself. 
tion force may be neglected, equation (F’”’) will obviously give 
us for the induction throughout the whole length S of the wire 
d?Q’ 8 
n P=43CKRSn*=4C72? de FR : 
: Pee ee ae 
“* (a) whence di ~cGn xP: 
¥ Here the whole inductive force P is, agreeably to the hypoth- . 
time 7, equation (@) gives us 
AQ’? 24 -2R 
(2) dit =Gu gPF | 
and this gives ; 
2° 5 : 
(c) Q’= Ga gy Pl 
charge, is proportional to its diameter, and inversely proportional 
to its length.* This differs essentially from the law of conduc- 
tion for galvanic currents in that the conducting power is directly 
as the diameter, while in constant galvanic currents it is as the — 
cross section or square of the diameter. a 
| __Again, equation (¢) shows that the conducting power (measur- ca 
_ ed by Q’) and the resistance to discharge, (measured by P), may 
os be considered as the reciprocals of each other, since any change 
. 
i trict 
: chine electricity through the two simultaneously, either by divid- 
} reen them, or joining them end to end and passing the 
whole charge through both. 
Be) Seatac een eee eer 
* Tt would be easy to show in a general way, that this law of electric ‘gisthares 
should ry to straight cond: tors having similar cross sections of any form, but I 
«do not « plate testing it with any other ihan round wire. 
