200 Dr. Faraday’s Experimental Researches in Electricity. — ‘ 
~ 2681. There is another distinction which may usefully be es- 
tablished between the effects of a = sustainable _— either 
magnetic or diamagnetic, and those of the transient induc 
rents dependent upon time. If we ssuisiaoe the iaddacab in the 
circuit, which includes the experimental helix and the galvanom- 
eter coil, as nothing, then a magnetic pole of constant strength 
passed a certain distance into the helix, would produce the same 
amount of current aging in it, whether the pole were moved 
-.-Into its place by a quick or slow motion. Or if the iron core be 
" _ used (2668.) the same result is produced, provided, in any alter- 
ee “ nating action, the core is left long enough at the extremities of 
ne ie its journey to acquire, either in its quick or slow alternation, the 
. - .game-state. This I found to be the fact when no commutator 
_ hor dominant magnet was used; a single insertion of a wea 
4 Magnetic pole. gave the: same deflection, whether introduced 
=<. quickly or slowly ; and when the residual dominant magnet, an 
aa . ‘iron wire core, and the commutator in its position, a, b were (2677.) 
Pas“ SE od, four. journeys to and from produced the same effect.at the gal- 
“val ter when the velocities were as 1: 5 or even as 1: 0. 
‘ 2682. Whew a copper, — or gold core is employed i in place 
mer) =, iron, the effect is very different. There is no a to 
oubt, tl a regards the core itself the same amoun of elec- 
| 
» ¥ rapid 
we: 
ae 
st: The extre ti, this, ex 
-1:6; the dine; in the longést ‘case siderably I 
at of one vibration of a ocr { resieeoe that beliewd all, 
force in the hog edle is very eer 
7 tae Fa eget of i pacts, because é fe 
+ er = ; is ‘ : 
cs : a *& 
4s 
% 
= ¥, 
A 
