Q. Why is the curing of an ulcer or bile in the kidney or bladder very hard? A. Because the urine, being sharp, doth ulcerate the sore. Ulcers are worse to cure in the bladder than in the kidneys, because the urine stays in the former, but runs away from the latter.
Q. Why do chaff and straw keep water hot, but make snow cold? A. Because the nature of chaff wants a manifest quality; seeing, therefore, that of its own nature it can be easily mingled, and consumed by that which it is annexed unto, it easily assumes the same nature, and being put into hot things, it is easily hot, heats again, and keeps hot; and, on the contrary, being made cold by the snow, and making the snow cold, it keeps it in its coldness.
Q. Why have we oftentime a pain in making water? A. Because sharp choler issuing out, and pricking the bladder of the urine, doth provoke and stir up the whole body to ease the part offended and to expel the humour moderately. This doth happen most of all unto children, because they have moist excrements, by reason of their often filling.
Q. Why have some medicines of one kind contrary effects, as experience proves; for mastich doth expel, dissolve, and also knit; and vinegar cools and heats? A. Because there are some invisible bodies in them, not by confusion, but by interposition; as sand moistened doth clog together and seem to be but one body, though indeed there are many small bodies in sand. And since this is so, it is not absurd that contrary qualities and virtues should be hidden in mastich, and that nature hath given that virtue to these bodies.
Q. Why do nurses rock and move their children when they would draw them to sleep? A. To the end that the humours being scattered by moving, may move the brains; but those of more years cannot endure this.
Q. Why doth oil, being drank, cause one to vomit, and especially yellow choler? A. Because, being light, and ascending upwards, it provoketh the nutriment in the stomach, and lifteth it up, and so the stomach being grieved, summoneth the ejective virtue to vomit, and especially choler, because that is light, and consisteth of subtle parts, and therefore the sooner carried upward; for when it is mingled with any moist thing, it runneth into the highest room.
Q. Why doth not oil mingle with moist things? A. Because, being pliant, soft, and thick in itself, it cannot be divided into parts, and so cannot be mingled; neither if it be put on earth can it enter into it.
Q. Why are water and oil frozen in cold weather, and wine and vinegar are not? A. Because that oil, being without quality, and fit to be compounded with any thing, is cold quickly, and so extremely, that it is most cold. Water, being cold of nature, doth easily freeze when it is made colder than its own nature. Wine being hot, and of subtle parts, suffereth no freezing.
Q. Why do contrary things in quality bring forth the same effect? A. That which is moist is hardened and bound alike by heat and cold. Snow and liquid do freeze with cold; a plaster, and gravel in the bladder, are made dry with heat. The effect indeed is the same, but by two divers actions; the heat doth consume and eat the abundance of moisture; but the cold stopping and shutting with its overmuch thickness, doth wring out the filthy humidity, like as a sponge wrung with the hand doth cast out the water which it hath in the pores or small passages.
Q. Why doth a shaking or quivering seize us oftentimes when any fearful matter doth happen, as a great noise or crack made, the sudden downfall of water, or the fall of a large tree? A. Because that oftentimes the humours being digested and consumed by time, and made thin and weak, all the heat, vehemently, suddenly, and sharply flying into the inward part of the body, consumeth the humours which cause the disease.