The history of the ‘waters of life’ is as convoluted as everything else in those parts. I thought I’d read that one of the Irish brands omitted the ‘e’ and assumed it was one of the Northern ones whose makers had made the short crossing from Scotland,but no,they all stick to the Irish spelling.
However,turns out that ‘Paddy’,distilled in Cork and favoured tipple of my wife’s late uncle,only adopted the Irish convention sometime in the 1960’s,no idea why.
McConnells distillery in Belfast use the Whisky spelling.
Interesting , as we started with Brandy, that the Brandy distillate is called ‘eau de vie’ which is the French for’ Uisce Beatha’, i.e. Whiskey