Ickle Dorrit: Maybe I'm just too tired, but I can't find any connection between "My Bonny" and "George Campbell" at Lesley's site.  I did eventually find a link to a brief discussion of "My Bonny" in the Ballads discussion list, where somebody suggested a link to the Young Pretender; without giving any evidence beyond hearsay, unfortunately.   (here).  Steve Roud's contribution,   here, seemed more convincing.  The Watersons' version of Barney (as pointed to by Wolfgang) and Cecilia Costello's Johnny (Sandy Paton's link) certainly appear to be the same song, though no tune is given with the DT entry.  The 1919 Barney that Bruce mentions is of course a parody, quoting just pieces of the familiar tune.   To confuse the issue further, there is another song at the Music for the Nation collection,  My Barney Is Out On The Sea, which appears to be an entirely different song (words Arthur N. French, music C. A. White; 1876) on the same theme, with a very Victorian Parlour feel to it.  Without any evidence, I'd guess that this may be a "spin-off" from the better-known song, written to cash in on its success?  This is getting interesting, and I do hope that somebody will be able to take us further!

Malcolm