Vienna Lemon Cream

Stir the yolks of 10 eggs with 1 cup sugar to a cream; add the juice of 4 lemons and the grated rind of ½ a one; lay 12 sheets of gelatine in cold water for 10 minutes, press out and dissolve it in ½ cup boiling water; add it by degrees to the cream and continue stirring till it begins to thicken; then add the whites, beaten to a stiff froth; rinse out a form with cold water and sprinkle with sugar, turn in the cream and set on ice till firm.