Q. What causes man to yawn or gape? A. It proceeds from the thick fume and vapours that fill the jaws; by the expulsion of which is caused the stretching out and expansion of the jaws, and opening of the mouth.
Q. Why doth a man gape when he seeth another doing the same? A. It proceeds from the imagination. And this is proved by the similitude of the ass, who, by reason of his melancholy, doth retain his superfluity for a long time, and would neither eat nor make water unless he should hear another doing the like.
Of the Teeth.
Q. Why do the teeth only, amongst all other bones, experience the sense of feeling? A. That they may discern heat and cold, that hurt them, which other bones need not.
Q. Why have men more teeth than women? A. By reason of the abundance of heat and blood, which is more in men than women.
Q. Why do the teeth grow to the end of our life, and not the other bones? A. Because otherwise they would be consumed with chewing and grinding.
Q. Why do the teeth only come again when they fail, or be taken out, and other bones being taken away grow no more? A. Because all other bones are engendered of the humidity which is called radical, and so they breed in the womb of the mother; but the teeth are engendered of nutritive humidity, which is renewed and increased from day to day.
Q. Why do the fore-teeth fall in youth, and grow again, and not the cheek teeth? A. From the defect of matter, and from the figure; because the fore-teeth are sharp, and the others broad. Also, it is the office of the fore-teeth to cut the meat, and therefore they are sharp; and the office of the other to chew the meat, and therefore they are broad in fashion, which is fittest for that purpose.
Q. Why do the fore-teeth grow soonest? A. Because we want them sooner in cutting than the others in chewing.
Q. Why do the teeth grow black in human creatures in their old age? A. It is occasioned by the corruption of the meat, and the corruption of phlegm, with a choleric humour.