How to make:
POUR absinthe into glass. PLACE cube of sugar on a slotted absinthe spoon resting across the top of the glass. Using an absinthe fountain (or a bottle of chilled mineral water with a small hole in the cap), DRIP iced water over the sugar so it dissolves and drips into the glass. Traditionally the same amount of water is added as absinthe, but full-strength absinthe requires more dilution - Keep dripping until absinthe louches (turns milky white). Add ice, stir and serve.
Patience is a virtue. Slow dripping of the water is essential to dissolve the entire sugar cube and give the drink enough sweetness to balance the absinthe.
This is the traditional method of serving absinthe. It was common until shortly before the First World War, when the drink was banned in most countries.