1. Thoroughly mix gelatin, 1/2 cup sugar and salt in sauce pan.

2. Beat together egg yolks, lime juice and water. Stir into gelatin mixture.

3. Cook and stir over medium heat just till mixture comes to boiling.

4. Remove from heat, stir in grated peel. Add food coloring (to tint to pale green).

5. Chill, stirring occasionally until mixture mounds slightly.

6. Beat egg whites until soft peaks form. Gradually add 1/2 cup sugar into egg whites, beating to stiff peaks.

7. Fold gelatin mixture into egg whites.

8. Fold in whipped cream.

9. Pile into cooled baked pastry shell. Chill till firm.