Combine gelatin, 1/4 sugar, 1/2 cup cold milk and salt. Let stand 1 minute. Beat egg yolks and remaining milk. Stir into gelatin mixture. Cook, stirring over *low* heat about 5 minutes.
Remove from heat. Stir in vanilla. Chill until it mounds slightly when dropped from spoon.
Beat egg whites and cream of tartar. Beat in 1/4 cup sugar slowly. Fold gelatin mixture into egg whites. Pour into mold and chill at least 8 hours.
Top with custard sauce, whipped cream or crushed berries.