Cut small and core an equal amount of tart apples and ripe quince. Put the quince in a preserving kettle with water to cover and boil until soft; add the apples, still keeping water to cover them. Boil until soft pulpy sauce. Put the whole into a cloth bag and strain without pressure. To each quart of juice allow 2 pounds of lump sugar. Boil together half an hour. Put into containers and seal.