How to Make It
Combine sugar and water in a medium saucepan; bring to a simmer over high heat, stirring constantly. Reduce heat to medium-low, and add sliced celery; cook 8 minutes. Cool completely. Strain; discard celery. In each of 8 glasses, combine 1 1/2 ounces gin, 2 1/2 tablespoons celery syrup, and 1/2 teaspoon fresh lemon juice. Top each with 1/3 cup chilled club soda. Add ice, and garnish, if desired.