As anybody who's tripped and fallen after a pissed perambulation along its bank can tell you, the Regent's Canal doesn't have the most palatable taste. This hasn't dissuaded one mercurial bud-tickler, however, who has created an ice cream with a taste based on things found alongside the canal's murky waters. Eschewing the flotsam of rubber boots, trolleys and countless knows how many chthonic creepies, Arthur Potts Dawson, a restaurateur from the Kings Cross area,......