Preheat oven to 300 degrees. Grease and flour a large Bundt-style or ring pan. In a large mixing bowl, add 3 egg yolks, one at a time, beating well after each addition. Add the sugar and beat until light and fluffy. Set aside. In a separate bowl, beat 3 egg yolks, one at a time, beating well after each addition. Add the butter and beat until white in color. Combine both mixtures in a single bowl. Stir together flour, nutmeg and salt until well mixed. Gradually add to batter, mixing well. Soak the raisins in the bourbon and roll the finely chopped nuts in a little flour; stir into batter. In a clean bowl, beat the 6 egg whites. Gently fold the beaten whites into the batter. The batter should be thick and heavy, but a small amount of water can be stirred in if needed to make a batter which can be stirred smoothly. Bake in a 300 degrees oven for 30 minutes, then reduce heat to 275 degrees and bake for 2 to 2 1/2 hours or until cake has begun to pull away from the side of the pan.