Chill a coupe glass.
Combine the gin, dry vermouth, sweet vermouth and orange juice in a shaker.
Add two dashes of Angostura bitters.
Add ice and shake hard for 10 seconds.
Fine-strain into the chilled coupe and express an orange twist over the top.
A Prohibition-era variation on the Bronx, recorded in the Savoy Cocktail Book. The name is a joke about the then-novel American federal income tax: the bitters are the deduction. Shake it briskly enough to aerate the orange juice.
My Bar Shelf reads your shelf and shows you every cocktail you can make from what you already own, including Income Tax.