Ernest Hemingway gets credit for the recipe. His advice, circa 1935: "Pour one jigger absinthe into a Champagne glass. Add iced Champagne until it attains the proper opalescent milkiness. Drink three to five of these slowly." We recommend drinking fewer than five. You may also try pouring the absinthe on top instead—some brands of absinthe will float for a time on the Champagne, and this makes for a nifty visual effect.