Assemble all the ingredients in a mixing glass with ice, squeeze the lemon wedge and drop it in, shake well, and strain into a chilled cocktail glass.
Adapted from Jerry Thomas's How to Mix Drinks, 1862. This can also be served over crushed ice with berries as a garnish. Variation: When raspberries are in season, omit the raspberry syrup and muddle 6 to 8 raspberries with the lemon juice and curaçao in the bottom of a mixing glass. Add remaining ingredients and shake well with ice.