Cover figs with boiling water, let stand 10 minutes, drain and dry on towel. Clip stems and cut figs into thin strips. Sift white flour with baking powder, salt and sugar. Add whole wheat flour and stir to blend. Work butter into flour mixture. Add sour milk in which soda has been dissolved and mix. Add beaten eggs, nuts and figs, and beat. Pour into a paper-lined loaf pan (about 10x5x3 inches). Bake in moderate oven (350 F.) about 1 hour and 25 minutes. Serve hot with butter, or cool and slice very thin for tea sandwiches. Makes excellent toast when one or two days old.