Dissolve the soda in a cupful of lukewarm water. Put the butter into the molasses, and let them warm until the butter is melted. Add to it the dissolved soda and water, and the salt. Stir this mixture into the sponge, and add enough Graham flour to make a stiff batter, or very thin dough. Turn into a greased pan. Let it rise until even with the top of the pan, and bake in a moderate oven an hour or an hour and a quarter. Use a spoon, and not the hands, for mixing Graham flour. A little white flour may be mixed with the Graham flour if a lighter colored and dryer bread is preferred.