From 1922, from the Jell-O Museum and Gallery, http://www.jellogallery.org/
Dissolve a package of Lemon Jell-O in a scant 2 cups of boiling water and 2 tablespoons of vinegar. Add one pimento, one half of a green pepper cut fine, and half a cup of grated horseradish. As it begins to thicken mold in sweet green peppers, and when set, cut into slices. Serve with meat of fish.