Original Receipt in Eaton 1822BLACKBERRY JAM.
Put some red, but not ripe, blackberries into a jar, and cover it up closely. Set the jar in a kettle or deep stewpan of water over the fire, as a water bath; and when it has simmered five or six hours, force the juice through a sieve. To every pint of juice, add two pounds of powdered loaf-sugar, boiling and scumming it in the same manner as for any other jam or jelly. This simple article is said to afford effectual relief in cases of stone or gravel: a tea-spoonful to be taken every night, and repeated in the morning, if necessary. A good jam may also be made of ripe blackberries, in a similar manner; and both, like other jams, should be kept in jars, closely tied over with brandy paper.