The song is by Allan Ramsay and without music in 'The Tea Table Miscellany' (I), 1723/4. The tune seems to be first found in Joseph Mitchel's ballad opera 'The Highland Fair', 1731. Song and tune are in 'Orpheus Caledonius', II, 1733 (reprinted) and 'The Scots Musical Museum', #169 (reprinted). The song was not very popular. I've not found other copies of song or tune in 18th century Scots works. Maybe Murray S. can tell us more.