As to the variety and weakness of the rationale of this art, they are more manifest in it than in any other art; aperitive medicines are proper for a man subject to the stone, by reason that opening and dilating the passages they help forward the slimy matter whereof gravel and stone are engendered, and convey that downward which begins to harden and gather in the reins; aperitive things are dangerous for a man subject to the stone, by reason that, opening and dilating the passages, they help forward the matter proper to create the gravel toward the reins, which by their own propension being apt to seize it, 'tis not to be imagined but that a great deal of what has been conveyed thither must remain behind; moreover, if the medicine happen to meet with anything too large to be carried through all the narrow passages it must pass to be expelled, that obstruction, whatever it is, being stirred by these aperitive things and thrown into those narrow passages, coming to stop them, will occasion a certain and most painful death. They have the like uniformity in the counsels they give us for the regimen of life: it is good to make water often; for we experimentally see that, in letting it lie long in the bladder, we give it time to settle the sediment, which will concrete into a stone; it is good not to make water often, for the heavy excrements it carries along with it will not be voided without violence, as we see by experience that a torrent that runs with force washes the ground it rolls over much cleaner than the course of a slow and tardy stream; so, it is good to have often to do with women, for that opens the passages and helps to evacuate gravel; it is also very ill to have often to do with women, because it heats, tires, and weakens the reins. It is good to bathe frequently in hot water, forasmuch as that relaxes and mollifies the places where the gravel and stone lie; it is also ill by reason that this application of external heat helps the reins to bake, harden, and petrify the matter so disposed. For those who are taking baths it is most healthful. To eat little at night, to the end that the waters they are to drink the next morning may have a better operation upon an empty stomach; on the other hand, it is better to eat little at dinner, that it hinder not the operation of the waters, while it is not yet perfect, and not to oppress the stomach so soon after the other labour, but leave the office of digestion to the night, which will much better perform it than the day, when the body and soul are in perpetual moving and action. Thus do they juggle and trifle in all their discourses at our expense; and they could not give me one proposition against which I should not know how to raise a contrary of equal force. Let them, then, no longer exclaim against those who in this trouble of sickness suffer themselves to be gently guided by their own appetite and the advice of nature, and commit themselves to the common fortune.