Seven Minute Icing
["1 c. sugar", "1/2 tsp. cream of tartar", "1/4 tsp. salt", "2 unbeaten egg whites", "3 Tbsp. water", "1 tsp. vanilla"]
["Put all ingredients in double boiler; beat continuously over boiling water for 7 minutes."]
["sugar", "cream of tartar", "salt", "egg whites", "water", "vanilla"]