In a large bowl, sift 3 cups flour with spices. In another bowl, mix raisins, sultana raisins, currants, citron, and citrus rinds; dredge with 1/3 cup flour. Stir raisin mixture into the flour.
In a very large bowl, cream the butter or margarine. Beat in sugar, a small amount at a time. Add beaten egg yolks, flour mixture, brandy, chocolate and molasses. Beat egg whites until stiff, and fold them into the batter. Dissolve baking soda in hot water and stir gently into batter. Grease and flour 5 bread pans, and pour batter into prepared pans.
Bake at 275 degrees F (135 degrees C) for 4 hours. Cool. Cut into 275 to 300 slices; wrap each slice.