Inaugural Address by the President. 25 



was therefore correct in his prophecy. I attribute this negative 

 result to the extreme difficulty of removing the chemically 

 active matters from about the plates. 



Several other forms of experiment were devised to obtain 

 evidence on the question. In the result I can say that I have 

 found nothing to definitely contradict and much to support the 

 hypothesis I adopted originally. 



In considering the true nature of the effect in Volta's funda- 

 mental experiment, I concluded that its explanation would be 

 found in a modification of the theory originally put forth by 

 De la Rive/^ that the electrification was produced by electrolytic 

 chemical action on the metallic surfaces, and that the electrolyte 

 acting on these sui faces was condensed on them in the form of 

 a liquid film. In the ordinary atmosphere this film is doubtless 

 chiefly water with oxygen, carbonic acid, etc., in solution. Its 

 basis is doubtless in all cases water, while any gases present 

 would dissolve in this aqueous film. In confirmation of this it 

 was found that when by exceedingly careful and patient 

 manipulation the plates of the zinc-copper Volta condenser 

 were brought exceedingly close together, but not actually 

 touching, the films on their surfaces came together and acted 

 together as the liquid conductor of a cell, and a continuous 

 current could be obtained from the cell so formed^* sufficient to 

 deflect a galvanometer connected to the condenser plates. 



Such a theor}' explains the action of the Volta condenser and 

 that of the cell as really the same, in so far as either can be 

 explained. In so doing it has to admit that we know very little 

 about either of them. I believe that is one of the attributes 

 that characterises it as non-acceptable in comparison with 

 theories which, based on large and ill-supported assumption, 

 profess to explain everything. 



13. Traite d' Elecfiieite 11., p. 776. 



14. Proc. Roy. Soc, XLJ., p. 307, 1886, also Repertorium der Physik, XXIII., 



P 732- 



