While discussing some of Mr Smith's applications of Maxwell's ingenious idea of representing galvanic currents by the motions of an imaginary fluid (ante, p. 79), I was led to the present investigation. I have since found that, as was only to be expected, I had been anticipated in a great many of the results I obtained — especially by Stokes, in the Trans. of the Cambridge Phil. Soc. 1843. Still it appears to me that I have a few novel results to communicate.