This is the oldest version of the cocktail I could find (1916). It contains Crème de Violette. Later versions left have mistakenly left this ingredient out. Now it's practically unheard of to add Crème de Violette. The story goes that when the Savoy Cocktail Book came out an editorial blunder was to blame for the ommision. Which is too bad because the Crème de Violette is what gives this drink it's lovely sky blue hue, and that color is quite possibly the inspiration for the name. Aviation Cocktail.