130 MR. FARADAY’S EXPERIMENTAL RESEARCHES IN ELECTRICITY. 
touching each other by an interposed cloth, the effect at the indicating galva- 
nometer, or helix, occurred as before. The induced electricity could also pass 
through the trough (20.). When, however, the quantity of fluid was reduced 
to a drop, the galvanometer gave no indication. 
24. Attempts to obtain similar effects to these by the use of wires conveying 
ordinary electricity were doubtful in the results. A compound helix similar 
to that already described (6.), and containing eight elementary helices was 
used. Four of the helices had their similar ends bound together by wire, and 
the two general terminations thus produced connected with the small magnet- 
ising helix contained an unmagnetised needle (13.). The other four helices 
were similarly arranged, but their ends connected with a Leyden jar. On 
passing the discharge, the needle was found to be a magnet ; but it appeared 
probable that a part of the electricity of the jar had passed off to the small 
helix, and so magnetised the needle. There was indeed no reason to expect 
that the electricity of a jar possessing as it does great tension, would not dif- 
fuse itself through all the metallic matter interposed between the coatings. 
25. Still it does not follow that the discharge of ordinary electricity through 
a wire does not produce analogous phenomena to those arising from voltaic 
electricity; but as it appears impossible to separate the effects produced at 
the moment when the discharge begins to pass, from the equal and contrary 
effects produced when it ceases to pass (16.), inasmuch as with ordinary 
electricity these periods are simultaneous, so there can be scarcely any hope 
that in this form of the experiment they can be perceived. 
26. Hence it is evident that currents of voltaic electricity present pheno- 
mena of induction somewhat analogous to those produced by electricity of 
tension, although, as will be seen hereafter, many differences exist between 
them. The result is the production of other currents, (but which are only 
momentary,) parallel, or tending to parallelism, with the inducing current. By 
reference to the poles of the needle formed in the indicating helix (13. 14.) and 
to the deflections of the galvanometer-needle (11.), it was found in all cases 
that the induced current, produced by the first action of the inducing current, 
was in the contrary direction to the latter, but that the current produced 
by the cessation of the inducing current was in the same direction. For the 
purpose of avoiding periphrasis, I propose to call this action of the current 
