In the top of a double boiler, dissolve gelatin in 1/2 cup water. Add lemon juice and peel. Set aside.
In a saucepan, mix sugar with remaining 1/2 cup water and boil over high heat until the mixture reaches the medium ball state (238℉ on a candy thermometer.
In a clean, dry bowl, beat egg whites with salt until soft peaks form.
Gradually add sugar syrup to egg whites, beating constantly, until the mixture is frothy like meringue.
Add dissolved gelatin and beat it thoroughly.
Pour into a 1 ½ quart mold and chill for at least 2 hours, or until firm. * see notes
To unmold, set form in hot water for several seconds before turning out onto a deep serving platter. Serve with colorful fruits such a strawberries or b lack cherries and Custard Sauce* if desired.