354 Experimental Researches in Electricity. 



His first object was to determine whether the same abso- 

 lute quantity of ordinary electricity sent through a galvano- 

 meter under different circumstances, would cause the same 

 deflection of the needle. A battery of eight jars was first em- 

 ployed, and was charged by thirty turns of a common ma- 

 chine, this charge was sent through a galvanometer to 

 which an arbitrary scale, each division of which measured 

 4°, was attached, a thick wet string, about 10 inches in 

 length, being included in the circuit. The needle was im- 

 mediately deflected 5\ divisions. 



Fifteen jars were next employed, and charged with pre- 

 cisely the same absolute quantity of electricity as in the 

 first experiment, namely, that derived from thirty turns of 

 the machine, and on discharge being made, as before, the 

 needle was deflected to precisely the same point as in the 

 former instance. The experiments were varied in different 

 ways, and the current was materially altered in intensity, al- 

 though continuing constant in quantity ; yet it appeared that 

 in all, the deflection of the needle was the same. Hence 

 then the interesting general conclusion arrived at was, that 

 if the same absolute quantity of electricity pass through the 

 galvanometer, whatever may be its intensity, the deflecting 

 force upon the magnetic needle is the same. 



An effort was then made to establish a ratio between the 

 quantity of electricity and the deflecting force, and although 

 the experiment was not quite decisive, still, Faraday consi- 

 dered it highly probable, that the deflecting force of an 

 electric current is directly proportional to the absolute quan- 

 tity of electricity passed, at whatever intensity that current 

 may be. The same inference is supported by an experiment 

 of Drs. Ritchie and Harris, which has proved the same law 

 to obtain in the case of the heating powers of an electric 

 current. 



The next point was to obtain a voltaic arrangement pro- 

 ducing an effect exactly equal to that just alluded to, and it 



