194 Dr. Faraday’s Experimental Researches in Electricity. 
an inch in diameter, and this affected the galvanometer, holding 
its needle 25° or 30° from zero. 
~ 2660. I made a solid helix cylinder, ———_ of an inch 
in diameter and 2 inches long, of covered copper wire, one-six- 
teenth of an inch thick, and employed this as the experimental 
core. When the two ends of its wire were unconnected, there 
was no effect upon the experimental helix, and consequently none 
at the galvanometer; but when the ends were soldered together, 
the needle was well affected. In the first condition, the currents, 
which tended to be formed in the mass of moving metal, could 
- ‘hot exist because the metal circuit was interrupted ; in the second 
they could, because the circuit was not interrupted ; and such di+ 
vision as remained did not interfere to prevent the currents. 
2661. The same results were obtained with other metals. A 
core cylinder of gold, made of er in was very power- 
~ ful in its effect on the galvanometer. A cylinder of silver, made 
- of sixpenny pieces, was very effectual ; bat a cylinder made of 
mR, hy art silver, pressed into a glass tube as closely as possible; 
ve no indications of action whatever. The same results were 
ae tained with disc cylinders of tin and lead, the effects being 
pcuytonate, to the condition of .. cud and lead as bad conductors. 
(265 
=¥ ie When iron was dixéded: jie effects were exactly the re- 
in ie It was ne 
ometerjarid: 
air gh op oa in its diaubion to that of i 
of? i ‘thted place (2656. ), on) ‘a 
* a distinctiog? m™m the a ctions*of a diamaghetic 
© #*menta wy es stablished accor cording as hey 
eg true rity, or meré; vtoshagn 
4 pets; ans for‘ th onsidér: 
E magn uc ‘polarity are the. Sal 
) ‘eat present; in relation't toxirdn. : 
v. | 2665. ge. ‘of any ‘kinds 
ant mand and withdrawn tie 
ty) then a mar 
a 
bes 
be 
a3 
