Soak the gelatin in the cold water until softened. Stir it into the scalding hot cream; add 1/3 cup sugar and all the milk. Cook and stir over low heat until very hot; do not let it boil.
Beat the egg yolks and remaining sugar. Add 1 tablespoon extra sugar if the eggs are large. Pour a little of the hot mixture over the yolks; then stir this into the first mixture and cook and stir about 2 minutes. Do not let it boil. Remove from the heat; let cool until thick. Add the vanilla, stiffly whipped egg whites with salt, and the nuts.
Pour into a wet mold. Chill thoroughly. Serve with cream or cold fruit sauce.