Inaugural Address by the President. 21 



two plates be joined for a moment by a metallic wire and then 

 separated, it is found that the zinc appears to be positively and 

 the copper negatively electrified. I say appears advisedly. 



If we neglect any possible actions of the atmosphere on the 

 metals we are tied to Volta's view. It is surprising, considering 

 the clear insight and the careful and persevering nature which 

 Volta possessed, that he did neglect such atmospheric action, 

 and continued to do so even after his brilliant invention of the 

 Voltaic pile and cell in 1799, in which, notwithstanding, the 

 obvious presence of chenical action, he still placed the seat oi 

 generation of the current at the contact of the two metals. I 

 am inclined to think that the large acceptance which Volta's 

 contact theory obtained subsequently was due in great measure 

 to his impressive and self-confident style of writing, to the care 

 he took to publish widely, and to the respect due to his 

 undoubted genious rather than to any convincing characteristic 

 in his experiments. For it is to be noticed that beginning with 

 Fabroni and Creve and culminating with our own immortal 

 Faraday, there was a succession of philosophers who maintained 

 that in all cases the electric effect was due to chemical action 

 upon the metals whether of the atmosphere on Volta's condenser 

 plates or of liquid in his cell. In the cell indeed the presence 

 of chemical action is evident, and the need of some such source 

 of energy to produce the continuous current of the cell is more 

 obvious. 



To illustrate this, I have here two metallic plates, one of 

 copper and one iron, placed in the necessary metallic contact 

 through a wire which forms part of this galvanoscope. When 

 placed in this jar of acidulated water the current generated 

 immediately deflects the pointer of the instrument. If the 

 experiment be continued for some hours, we find the iron has 

 been dissolved by the acid while the copper remains unacted 

 on. In Faraday's researches'' on many varieties of such cells it 

 was clear inter aha that contact of dissimilar metals was not 

 necessary (one metal and two liquids being also active), also that 



7. Experimental Researches in Electricity II., p. i8. 



