Recipe for the 2 in 1, a carbonated negroni / white lady combo cocktail, from The Aviary Cocktail Book, pages 212-213.

Carbonated Negroni

Ingredients:
Citadelle gin
Carpano Antiqua sweet vermouth
Regan’s orange bitters
Fee Brothers orange bitters
water

White Lady

Ingredients:
Citadelle gin
Lemon juice
Simple syrup
Egg white
Orange peel