Sprinkle gelatine over Jacquin's Rum in a Pyrex cup and let soften 5 minutes;
then put the cup in a small pan of simmering water and stir until gelatine is dissolved.
Meanwhile, beat egg yolks and sugar until very thick and light. Beat in grated
lemon rind and juice. With clean beaters, beat egg whites until stiff but not dry.
Whip 1 cup of the heavy cream. Stir the dissolved gelatine into the lemon mixture,
then fold in beaten egg whites and whipped cream.
Pour into a 1 1/2-quart soufflé
dish and refrigerate for at least 2 hours. (It can be made the day before serving.)
When ready to serve, whip remaining 1/2 cup heavy cream and garnish soufflé with
rosettes of whipped cream. Decorate with candied violets if you have them.