Experiments performed in trying to establish whether that current was the same as ordinary electricity were the ones that led directly to the discovery of the arc. They were in fact based on the study of the spark produced by contact between two leads connected to the terminal of a battery.
The first to use two pieces of carbon as conductors in such research was Sir Humphry Davy (1778-1829) in October 1800. In 1801, he reported this to the Royal Institution, of which he had just become the lecturer in chemistry. But, owing to the high internal resistance of the piles, caused by the small size of the zinc and copper plates, the batteries that Davy used could not produce the current necessary to produce and maintain the arc; he in fact did not mention that he had observed the formation and persistence of the arc in that experiment. ...continues