This salad takes time to prepare, since each layer must set until
firm before the next layer is added. Dissolve 1 package strawberry
gelatin in 2 cups of boiling water; pour into a 3 quart glass bowl.
Refrigerate until firmly set. Dissolve 1 envelope of unflavored
gelatin in 1/2 cup cold water; set aside. Over low heat, carefully
dissolve sugar in whipping cream; heat, stirring constantly, until
mixture nearly boils. Remove from heat; add unflavored gelatin
mixture. Cool. Blend in sour cream and vanilla; pour over first
layer. Refrigerate until firm. Dissolve 1 package raspberry gelatin
in 1 cup boiling water; cool. Add 1 can blueberries and juice. Pour
over second layer; refrigerate until firm.