the manhattan -- we're pretty sure it came first (*see below) -- is a mixture of 2 1/2 ounces of rye whiskey, 1 ounce sweet vermouth (which isn't as terrifying an ingredient as you think), and angostura bitters. the martini gets even simpler, with two ingredients: 2 3/4 ounces gin, and 3/4 ounce dry vermouth.