1. Stone the cherries, and tie the stones in muslin.
2. Put them in the pan, with the cherries and lemon juice.
3. Simmer over low heat until the juices begin to run and the fruit is tender.
4. Remove the muslin bag, stir in the sugar.
5. Bring to the boil and boil rapidly until setting point is reached.
6. Remove from the heat, skim, pot, cover, and label.