This was given by Thomas Young, who, in the Bakerian lecture delivered before the Royal Society on the 24th of November 1803, applied his principle of the interference of light to this phenomenon.
For an example of such a diagram, see the Bakerian Lecture, 1903, Phil.
This expedition formed the subject of the Bakerian Lecture already referred to.
A year after this paper, which gained him from the French Institute the medal offered by Napoleon for the best experiment made each year on galvanism, he described in his second Bakerian lecture the electrolytic preparation of potassium and sodium, effected in October 1807 by the aid of his battery.
At the end of 1808 he read his third Bakerian lecture, one of the longest of his papers but not one of the best.