in Magnetism and Electricity. Ill 



with the liquid coil*; and since the arrival at the galvanometer 

 of the induction-current must necessarily have been preceded by 

 its generation in the convolutions of the aqueous conductor 

 surrounding the armature, this experiment affords another proof 

 that the presence of an electrode, whether employed in transmit- 

 ting or in receiving an electric current, is essential to the pro- 

 duction of electrolytic phenomena. But in a modification of 

 this experiment which I have made with a water helix formed 

 in an india-rubber tube 37 feet in length, 20 feet of which were 

 coiled round the electromagnet, while the other 17 feet were 

 used simply as a conductor, after removing the galvanometer- 

 wires which had first indicated the generation of the induction- 

 current, and plunging the ends of the india-rubber tube into a 

 glass vessel containing the same acidulated water as that which 

 filled the tube, in order that the induced current should now be 

 generated and propagated in a closed homogeneous circuit of 

 water returning into itself, it is manifest that though the in- 

 duced current would be generated and conducted as certainly as 

 when the galvanometer formed part of the circuit, yet, owing to 

 the absence of electrodes, there could be no electrolyzation of 

 the water in any part of the circuit. Hence, if Faraday failed 

 to prove that a feeble electric current could be transmitted from 

 an electrode into an electrolyte without electrolyzation, this great 

 philosopher has at any rate the rare merit of having indicated the 

 only method by which a current can be generated and propa- 

 gated in an electrolyte without the intervention of electrodes, 

 and consequently without electrolyzation. 



213. From a further comparison of the phenomena attending 

 the propagation of an electric current in an aqueous circuit with 

 those observed in a metallic one (both closed and interrupted), 

 it would appear that the electrolytic products which make their 

 appearance at the point of interruption of an aqueous circuit 

 such as we have just considered (212), are the result of the dis- 

 ruptive discharge of the electrolyte against the electrode, just as 

 the spark or the electric light is the result of the disruptive dis- 

 charge from metallic or graphite conductors through air, — the 

 principal difference between the two discharges (and one which 

 exhibits in a remarkable manner the transmutations of matter 

 and force) being this, that whereas the ponderable particles of 

 matter which are projected from solid conductors (such as metals 

 or graphite) by the disruptive discharge give out the whole of 

 their specific energies in the form of heat and light at the moment 

 of discharge, the specific energies of the ponderable particles of 

 matter which are projected from the water by the electrolytic 

 discharge, on the contrary, remain suspended until they are 

 * Philosophical Magazine, S. 4, vol. viii. p. 465. 



