Robert Burns, John Gibson Lockhart, James Currie (1835). “The works of Robert Burns: containing his life, by John Lockhart, esq. ; the poetry and correspondence of Dr. Currie's edition ; biographical sketches of the poet by himself, Gilbert Burns, Professor Stewart, and others”, p.141
"Experiments With Alternate Currents Of High Potential And High Frequency". Nikola Tesla's Address to the Institution of Electrical Engineers, February 1892.