San Martin
1 1/2 ounces gin
1 1/2 ounces sweet vermouth
1 teaspoon Yellow Chartreuse
Garnish: lemon peel
Stir with ice, strain into a cocktail glass.
Source: Cocktails: How to Mix Them, by Robert Vermeire (1922)
This apparently was a famous South American drink in the day. Named after Jose de San Martin who liberated Argentina, Chile, and Peru from the Spanish.