Stir sugar into boiling water. Let cool. Add other liquids and freeze. Remove from freezer half hour before serving. Scoop out slush into punch bowl. When bowl is half full, slowly add lemon-lime soda (1 gallon maximum). Slush mixture with back of spoon before serving. This can also be done on a per-serving basis. Put frozen mixture in a glass, and add soda. Stir Contributed by Lawrence and Cindy Kellie Lawrence's mother introduced us to this delicacy.