166 DR. FARADAY'S EXPERIMENTAL RESEARCHES IN ELECTRICITY. (SERIES XIII.) 



transversely to a steel needle, will magnetise it as well as if the electricity of the spark 

 were conducted by a metallic wire occupying- the line of discharge; and Sir H. Davy 

 has shown that the discharge of a voltaic battery in vacuo is affected and has motion 

 given to it by approximated magnets*. 



1657. Thus the three very different modes of discharge, namely, conduction, elec- 

 trolyzation, and disruptive discharge, agree in producing the important transverse 

 phenomenon of magnetism. Whether convection or carrying discharge will produce 

 the same phenomenon has not been determined, and the few experiments I have as yet 

 had time to make do not enable me to answer in the affirmative. 



1658. Having arrived at this point in the consideration of the current and in the 

 endeavour to apply its phenomena as tests of the truth or fallacy of the theory of in- 

 duction which I have ventured to set forth, I am now very much tempted to indulge 

 in a few speculations respecting its lateral action and its possible connexion with 

 the transverse condition of the lines of ordinary induction (1 165. 1304.). I have long 

 sought and still seek for an effect or condition which shall be to statical electricity 

 what magnetic force is to current electricity ; for as the lines of discharge are asso- 

 ciated with a certain transverse effect, so it appeared to me impossible but that the 

 lines of tension or of inductive action, which of necessity precede that discharge, 

 should also have their correspondent transverse condition or effect (951.). 



1659. According to the beautiful theory of Ampere, the transverse force of a cur- 

 rent may be represented by its attraction for a similar current and its repulsion of a 

 contrary current. May not then the equivalent transverse force of static electricity 

 be represented by that lateral tension or repulsion which the lines of inductive action 

 appear to possess (1304.)? Then again, when current or discharge occurs between 

 two bodies, previously under inductrical relations to each other, the lines of inductive 

 force will weaken and fade away, and, as their lateral repulsive tension diminishes, 

 will contract and ultimately disappear in the line of discharge. May not this be an 

 effect identical with the attractions of similar currents ? i. e. may not the passage of 

 static electricity into current electricity, and that of the lateral tension of the lines of 

 inductive force into the lateral attraction of lines of similar discharge, have the same 

 relation and dependencies, and run parallel to each other ? 



1 660. The phenomena of induction amongst currents which I had the good fortune 

 to discover some years ago (6. &c. 1048.) may perchance here form a connecting link 

 in the series of effects. When a current is first formed, it tends to produce a current 

 in the contrary direction in all the matter around it ; and if that matter have con- 

 ducting properties and be fitly circumstanced, such a current is produced. On the 

 contrary, when the original current is stopped, one in the same direction tends to 

 form all around it, and, in conducting matter properly arranged, will be excited. 



* Philosophical Transactions, 1821. p. 427. 



