1/2 teaspoon powdered sugar
1 egg white
1/2 lemon, juice of
2 oz. dry gin
1 teaspoon green creme de menthe
carbonated water

Shake well with cracked ice and strain into 8-ounce highball glass. Fill with carbonated water.

From the book: Old Mr Boston's De Luxe Official Bartender's Book compiled and edited by Leo Cotton (Ben Burke, Inc, 1941)