Lemon Ice Box Pudding

3 eggs, separated
1/2 cup granulated sugar
Juice of 2 lemons or 1/4 cup juice
4 tablespoons granulated sugar
1/2 pint whipping cream, whipped
Vanilla wafers

Beat egg yolks until creamy, adding the 1/2 cup sugar gradually. Add lemon juice. Put in top of double boiler and cook until thick, stirring constantly. Whip 3 egg whites until stiff. Add the 4 tablespoons sugar. Add beaten egg whites to yolk mixture. Whip cream until thick and add to egg mixture. Mix well. Crush vanilla wafers. Put layer of custard in flat 2-quart casserole. Cover with layer of cracker crumbs and repeat layers. Chill until serving time.