The walnuts should be gathered while young and soft, (so that you can easily run a pin through them,) and when the sun is upon them. Rub them with a coarse flannel or tow cloth to get off the fur of the outside. Mix salt and water strong enough to bear an egg, and let them lie in it a week, (changing it every two days,) and stirring them frequently. Then take them out, drain them, spread them on large dishes, and expose them to the air about ten minutes, which will cause them to blacken the sooner. Scald them in boiling water, (but do not let them lie in it,) and then rub them with a coarse woollen cloth, and pierce every one through in several places with a large needle, (that the pickle may penetrate them thoroughly.) Put them into stone jars, and prepare the spice and vinegar. To a hundred walnuts allow a gallon of vinegar, an ounce of cloves, an ounce of allspice, an ounce of black pepper, half an ounce of mace, and half an ounce of nutmeg. Boil the spice in the vinegar for fifteen minutes, then strain the vinegar, and pour it boiling hot over the walnuts. Tie up in a thin muslin rag, a tea-cupful of mustard seed, and a large table-spoonful of scraped horse-radish, and put it into the jars with the walnuts. Cover them closely with corks and leathers.