21. But if the organ which contains the food should obtain sufficient material, not even so does the activity of the fire become quiescent: but it produces a sort of melting of the material just as in a foundry, and, dissolving the solids, pours them out and transfers them, as it were from a funnel, to the neighbouring passages: then separating the coarser from the pure substance, it passes the fine part through certain channels to the entrance of the liver, and expels the sedimentary matter of the food to the wider passages of the bowels, and by turning it over in their manifold windings retains the food for a time in the intestines, lest if it were easily got rid of by a straight passage it might at once excite the animal again to appetite, and man, like the race of irrational animals, might never cease from this sort of occupation.