This section is from the book "Preserving And Pickling", by Mary M. Wright. Also available from Amazon: Preserving and Pickling: Two Hundred Recipes for Preserves, Jellies, Jams, Marmalades, Pickles, Relishes and Other Good Things.
Peel and grate as many pineapples as you desire to put up in this way, and to each cupful of the grated pineapple add a cupful of rhubarb cut up into bits. Allow one pound of sugar to each pint of fruit. Mix well and stand in a cool place overnight. Cook until soft enough to pass through a sieve. Return to the preserving kettle and boil to a thick marmalade. Pour the marmalade into jars and seal
To each large pineapple use three large grapefruits. Peel and grate or chop the pineapple. Cut the grapefruits into quarters, and remove the fibers and the seeds from the centers; then cut up the pulp into very small pieces, and add some orange rind, being careful not to get any of the bitter pith. If you use orange the rind of one orange will be enough, or this may be omitted. To each cupful of fruit add a cupful of sugar, and a half cupful of water. Simmer slowly to the consistency of marmalade. Four into glasses or jars and seal while hot.
Peel and grate the pineapple, and to each cupful of the grated pineapple add one cupful of cherry pulp. The cherries should be soaked and seeded, and then passed through a food chopper. Mix the fruits well together, then add to each pint of the pulp one pound of sugar. Simmer slowly until tender, pass through a coarse sieve, and return to the kettle, and boil to the consistency of marmalade.
Wash the strawberries quickly, stem them, and place them in a preserving kettle. Crush them, then add to each pint of the pulp one cupful of grated pineapple. To each pint of the fruit mix ture add one pound of granulated sugar. Simmer slowly for twenty minutes or until a thick marmalade, and pour into jars.
Stew the prunes until tender, after they have been soaked overnight, then pass through a sieve. Crack some of the stones, pound the kernels to a paste and add to the prune pulp. To each pint of the pulp add one cupful of grated pineapple, and one pound of sugar, and one cupful of water. Simmer slowly until a thick marmalade and pour into glasses or jars.