Grate off the yellow rind; cut off the end and pack in salt for 8 days. Set them in a hot oven in dishes, turning until salt candies on them. Place them in a pot and pour on 2 gallons vinegar (boiling) to which has been added 2 pounds white mustard seed, 2 tablespoons mace, 1 pound ginger, 4 tablespoons celery seed, 1 pound black pepper, 2 pounds sugar and 1 handful horseradish (scraped). All the spices except mustard seed must be pulverized.