Electro-Magnetic Experiments. 407 
through the helices attached to the battery and while in this state 
one of its ends was quickly introduced into the helix connected with 
the galvanometer ; the deflection of the needle, in this case, was sev- 
en degrees. ‘The end of the rod wasnext introduced into the same 
helix while in its natural state and then suddenly magnetized ; the de- 
flection, in this instance amounted to thirty degrees, shewing a great 
superiority in the method of induction. 
The next attempt was to increase the magneto-electric effect while 
the magnetic power remained the same, and in this I was more suc- 
cessful. Two iron rods six inches long and one inch in diameter, 
armature, the deflection was, no.more,than. thirty-degrees.- 
result may perhaps have been samewhat affected by the want of 
p i ion in the several spires of the helices, it however 
over the other. A current from one of these helices deflected the 
needle one hundred degrees, and when both were used the needle 
was deflected with such force as to make a complete circuit. But 
the most surprising effect was produced when instead of passing the 
current through the long wires to the galvanometer, the opposite ends 
of the helices were held nearly in contact with each other, and the 
magnet suddenly excited ; in this ease a small but vivid spark was 
seen to pass between the ends of the wires and this effect was re- 
peated as often as the state of intensity of the magnet was changed. 
