Q. Why are all the senses in the head?  A. Because the brain is there, on which all the senses depend, and are directed by it; and, consequently, it maketh all the spirits to feel, and governeth all the membranes.

Q. Why cannot a person escape death if the brain or heart be hurt?  A. Because the brain and heart are the two principal parts which concern life; and, therefore, if they be hurt, there is no remedy left for cure.

Q. Why is the brain moist?  A. Because it may easily receive an impression, which moisture can best do, as it appeareth in wax, which doth easily receive the print of the seal when soft.

Q. Why is the brain cold?  A. 1.  Because that by this coldness it may clear the understanding of man and make it subtle. 2.  That by the coldness of the brain, the heat of the heart may be tempered.

Of the Eyes.

Q. Why have you one nose and two eyes?  A. Because light is more necessary to us than smelling; and therefore it doth proceed from the goodness of Nature, that if we receive any hurt or loss of one eye, the other should remain.

Q. Why have children great eyes in their youth, which become small as they grow up?  A. It proceeds from the want of fire, and from the assemblage and meeting together of the light and humour; the eyes, being lightened by the sun, which doth lighten the easy humour thereof and purge them:  and, in the absence of the sun, those humours become dark and black, and the sight not so good.

Q. Why does the blueish grey eye see badly in the day-time and well in the night?  A. Because greyness is light and shining in itself, and the spirits with which we see are weakened in the day-time and strengthened in the night.

Q. Why are men’s eyes of diverse colours?  A. By reason of diversity of humours.  The eye hath four coverings and three humours.  The first covering is called consolidative, which is the outermost, strong and fat.  The second is called a horny skin or covering, of the likeness of a horn; which is a clear covering.  The third, uvea, of the likeness of a black grape.  The fourth is called a cobweb.  The first humour is called albuginous, from its likeness unto the white of an egg.  The second glarial; that is, clear, like unto crystalline.  The third vitreous, that is, clear as glass.  And the diversity of humours causeth the diversity of the eyes.

Q. Why are men that have but one eye, good archers? and why do good archers commonly shut one?  And why do such as behold the stars look through a trunk with one eye?  A. This matter is handled in the perspective arts; and the reason is, as it doth appear in The Book of Causes, because that every virtue and strength united and knit together, is stronger than when dispersed and scattered.  Therefore, all the force of seeing dispersed in two eyes, the one being shut, is gathered into the other, and so the light is fortified in him; and by consequence he doth see better and more certainly with one eye being shut, than when both are open.