This tune was originally composed as a slow air in the key of Bb, written to lament the banning of whiskey manufacture in Scotland by British authorities. It appears in the key of G (classified under "miscellaneous") in O'Neill's Music of Ireland. It was converted to reel tempo somewhere along the line and as such is widely played in the "Anglo-Celtic" world.
Notation for the version in the key of A played here by Cosmas Sigsworth is in The Fiddle Music of Prince Edward Island.