This refreshing late-1800s cocktail from Old New York is a perfect summer sipper for a group.
Put sugar and water in a small saucepan over high heat and stir until sugar dissolves to make a syrup. Remove from heat.
Fill 4 tall glasses with ice. Into each, pour 2 ounces gin, 2 ounces lemon juice, and 1 to 2 teaspoons of the sugar syrup, depending on your taste. Top glass with soda water and stir. Garnish with lemon slices.