Inaugural Address by the Presiaent. 19 



As my work on voltaic theory is on the main line of research, 

 I would lead up to it by a brief reference to the history of the 

 subject. The earliest experiment in this connexion was a very 

 simple and now well-known one described by Sulzer^, in 1760, 

 in a paper on " The theory of agreeable and disagreeable 

 sensations" The experiment consisted in placing under the 

 tongue a plate of silver, and on top of the tongue a plate of lead 

 or zinc or other suitable metal. In bringing the outer ends of 

 these metals in contact a peculiar sensation is experienced in 

 the tongue. That this is really due to the formation of an 

 electric current passing through the tongue between the metals 

 was not even guessed at the time of its observation, nor for 

 many years afterwards. Yet its discoverer (if he had only known 

 it) was the first to observe the current from a voltaic cell. 



Science, however, does not progress by such co-ordinated 

 observations of isolated effects, and the first step towards the 

 discovery of the true character of the phenomenon was made by 

 the observation and connexion of two almost accidental effects 

 noted by Galvani,^ professor of anatomy at Bologna. 



In 1780 when investigating the nervous irritability of cold 

 blooded animals he observed that the limbs of a recently killed 

 frog, when hung by the crural nerve on a metal support near an 

 electric machine, contracted convulsively at the occurrence of 

 each spark drawn from the machine. Six years afterwards he 

 observed the same contraction when a copper hook, on which 

 the nerve hung, and the limb itself came simultaneously in con- 

 tact with an iron railing — the copper hook, the iron railing, 

 and the frog's leg forming thus a circuit of three bodies in 

 contact. The similarity of the result pointed to the same 

 cause— electricity. But how in this last mentioned case was 

 the electricity produced ? 



This question has exercised the scientific world ever since. 

 Galvani thought it was produced in the animal tissues, and 

 even went so far as to connect it with the spirit of the animal. 



1. Vide Electrochemie, Ostwald, p. 41. 



2. Ibid, p. 27. 3. Ibid, p. 45. 



