Connexion between Magnetism and Electricity. 387 
. If the extremes of a voltaic battery (we will suppose 
it = consist of 20 pairs of 8 inch plates,) be connected by 
a platinum wire, it becomes heated, and, if of sufficiently 
small diameter, it suffers ignition. ‘Let ts suppose such a 
wire W, lying upon the supports P and N, which represent 
the positieg: and negative con avers fees aire Voltaic 
appara s, P being connected with the first zine plate, and 
N a the last copper plate ; upon bringing thie north | 
of a common magnetic needle below and ata right angle to 
the platinum wire, it will be repelled or driven domnweht 4 
toe so that its north pole may be above the platinum wire, 
will then be attracted towards it. If the electric poles be 
bet these eae will also be reversed. 
at we suppose the conjunctive Eplesoun wire to be vertic- 
1 of horizont position approach it 
ther end of the e tea the needle will os- 
cillate, tr ‘will not be Sy attracted | or repelled b 
any part of the conjunctive wire—Professor Or TED. 
2. If a small steel bar be EE Mies to the conjunctive 
wire, and parallel to it, it does not become a polar magnet ; 
but if it be attached transversely, it does become polar, and 
it becomes north and south, or south and north, according 
to the direction of the supposed electric current traversing 
ithe conjunctive wire, Jenne as one nt of 
it is positive or n tive. us su V 
eee ee re | 
the platinum cqtyaciize wire of the 
