24 Inaugural Address by the President. 



chemical theories that had gone on for nearly a century. 



Immediately afterwards T arranged the experiment in the 

 form devised by Lord Kelvin where a metallic ring is formed — 

 half of one metal here copper, and the other half of a different 

 metal, here iron. Over the junction swings a delicately 

 suspended needle capable of being electrified. Lord Kelvin 

 showed that when positive the needle swings towards the 

 copper attracted by a negative electrification, if negative towards 

 the iron. I showed that these deflexions are reversed if the 

 atmosphere be charged with hydrogen sulphide in this case as 

 in that of the condenser method. 



Using copper and nickel plates in air and in hydrochloric 

 acid gas,^" the electrification is also reversed following its 

 analogous reversal in the corresponding cell. Finally, although 

 the requisite conditions obtain with only a few metals and 

 liquids, I was able to arrange five different experiments of an 

 analogous kind, and in all these the hypothesis was amply and 

 decidedly confirmed.^^ 



An attempt to annul the Voltaic effect by a removal of all 

 active chemical atmospheric matters from about the metals in 

 a more thorough way than had hitherto been employed was 

 made by sealing up in an exhausted glass tube this small Volta 

 condenser, together with a quantity of potassium intended to 

 absorb oxygen, etc.^'^ Means were provided for testing the 

 electric difference of potential. Lord Kelvin, I may mention, 

 told me I should not succeed in annulling the difference of 

 potential by these means. 



In my first experiment, which lasted six months, it was 

 reduced somewhat and increased on re-opening the tube. In a 

 second experiment lasting 18 months, and in a third lasting 

 seven years, there was no such effect observed. Lord Kelvin 



10. Phil. Mag. VII., p. 109, 1879. 



11. Proc. Roy. Soc, XLI., p. 301, i886. 



12. Ibid., LXIV., p. 369, 1899. 



