XXV111 



Brighton : — " We are here to refresh. I have heen working and writing 

 a paper that always knocks me up in health, but now I feel well again 

 and able to pursue my subject, and now I will tell you what it is about. 

 The title will be, I think, ' Experimental Researches in Electricity' : — I. 

 On the Induction of Electric Currents ; II. On the Evolution of Electri- 

 city from Magnetism ; III. On a new Electrical Condition of Matter ; 

 IV. On Arago's Magnetic Phenomena. There is a bill of fare for you, 

 and, what is more, I hope it will not disappoint you. Now the pith of all 

 this I must give you very briefly, the demonstrations you shall have in the 

 paper when printed. 



" I. When an electric current is passed through one of two parallel 

 wires, it causes at first a current in the same direction through the other, 

 but this induced current does not last a moment, notwithstanding the in- 

 ducing current (from the voltaic battery) is continued ; all seems un- 

 changed, except that the principal current continues its course. But 

 when the current is stopped, then a return current occurs in the wire 

 under induction, of about the same intensity and momentary duration, but 

 in the opposite direction to that first formed. Electricity in currents there- 

 fore exerts an inductive action like ordinary electricity, but subject to 

 peculiar laws. The effects are a current in the same direction when the 

 induction is established, a reverse current when the induction ceases, and 

 a peculiar state in the interim. Common electricity probably does the 

 same thing ; but as it is at present impossible to separate the beginning 

 and the end of a spark or discharge from each other, all the effects are 

 simultaneous and neutralize each other. 



" II. Then I found that magnets would induce just like voltaic cur- 

 rents, and by bringing helices and wires and jackets up to the poles of 

 magnets, electrical currents, were produced in them, these currents 

 being able to deflect the galvanometer, or to make, by means of the helix, 

 magnetic needles, or in one case even to give a spark. Hence the evolu- 

 tion of electricity from magnetism. The currents were not permanent ; 

 they ceased the moment the wires ceased to approach the magnet, because 

 the new and apparently quiescent state was assumed just as in the case of 

 the induction of current ; but when the magnet was removed, and its in- 

 duction therefore ceased, the return currents appeared as before. These 

 two kinds of induction I have distinguished by the terms volta-electric 

 and magneto-electric induction. Their identity of action and results is, 

 I think, a very powerful proof of M. Ampere's theory of magnetism. 



" III. The new electrical condition which intervenes by induction between 

 the beginning and end of the inducing current gives rise to some very curious 

 results. It explains why chemical action or other results of electricity have 

 never been as yet obtained in trials with the magnet. In fact the currents 

 have no sensible duration. 1 believe it will explain perfectly the transfer- 

 ence of elements between the poles of the pile in decomposition ; but this 

 part of the subject I have reserved until the present experiments are com- 



