Butterscotch Nut Frosting

1 cup light brown sugar
1/3 cup granulated sugar
1/3 cup hot water
1/8 teaspoon cream of tartar
1 egg white
1/8 teaspoon salt
1/2 teaspoon vanilla extract
1/2 cup chopped nut meats

Put sugar and water in saucepan over low heat and stir until sugar dissolved. Boil until syrup spins a thread (238 degrees F). Pour over egg white, beaten with cream of tartar, beating constantly until icing stands in peaks. Add salt and vanilla extract. Fold in chopped nuts.