Heat sugar, corn syrup and water in a saucepan, stirring until sugar has completely dissolved and mixture begins to boil. Cook the syrup to the hard-ball stage without stirring.
Beat the egg whites in a large bowl until quite stiff.
When syrup has reached the hard ball stage SLOWLY pour over the beaten egg whites while beating. Keep beating until the mixture is no longer shiny, about 10 minutes. Divinity will be very stiff. Mix in flavoring and chopped nuts if desired. Drop by spoonfuls onto waxed paper and let cool.