The earliest copy of the tune seems to be one in Alex. McGlashan's 'A Collection of Reels', c 1781 & 1786, followed by a copy in Vol. 3 of Aird's 'Airs' (1788). See the early Irish tune index on my website (in Mudcat's Links). There's another tune for the song composed by a Mr. Hewitt, as I recall (I'm not now at home where I could check this).