Soak the gelatin in cold water. Separate the eggs. Beat the egg yolks with the sugar until very creamy (with the beaters of a mixer), then add the juice of one lemon and the white wine. Form the gelatin dripping wet in a small pot and let it melt while stirring at low temperature. Slowly blend into the lemon foam, stirring throughout. Chill until the foam begins to gel. In the meantime, whip egg whites to very stiff peaks, fold into gelling cream. Place the cream in the refrigerator with the lid closed until firm.
Shortly before serving, cut the lemons into slices and place on top of the cream.