If chocolate squares are used, melt and cool. Cream next 4 ingredients til light and fluffy. Gradually beat in sugar. Add eggs, one at a time, beating thoroughly after each. Blend in chocolate. Add sifted dry ingredients alternately with orange juice, mixing til smooth. Fold in nuts and orange rind. Pour into 9 x 5 inch loaf pan lined with waxed paper. Bake at 300 for 1 hour and 45 minutes or til done. Let stand 5 minutes, then turn out of pan on rack to cool.