CHAPTER IV. 







Galvanic Electricity. 



THE first discovery connected with this branch 

 of physical science is found in a German work, 

 published in 1767, by Sultzer, entitled The Ge- 

 neral Theory of Pleasures. He observed, that if 

 two metals be applied, one above, and the other 

 below the tongue, and brought in contact, a 

 peculiar taste was perceived, attended with a 

 gentle flash of light; but that if applied sepa- 

 rately, no such effects were produced. 



It was next discovered accidentally by Gal- 

 vani, a distinguished professor of anatomy at 

 Bologna, that on touching the crural nerve of a 

 recently killed frog, which lay on a table, near 

 the conductor of an electrical machine in action, 

 with the point of a scalpel, all its muscles were 

 thrown into convulsions, as if seized with te- 

 tanus. By repeating the experiment on diffe- 

 rent animals, he found that the effect was most 

 remarkable in those which are cold blooded, 

 and have white muscles. He ascertained after- 

 wards, that when the nerves and muscles of 

 such animals were armed with small pieces of 



