Method. Cut the outer rind from the number of grapefruits to be preserved; cover with water, and add a very little salt, probably one teaspoon to three fruits, and soak in clear water two hours. Boil until tender, drain, scrape off any white fiber, and cut into small strips. Scoop out all the good fruit pulp, rejecting any seeds or white skin, add the prepared skin, and measure. Take an equal amount of sugar and cook fruit ten minutes. Add half of the sugar, cook ten minutes more, then stir in rest of sugar and cook until fruit jellies. Seal as other fruit.
Method. Use two oranges to one grapefruit, and proceed as directed for grapefruit marmalade.