Of the Hands.
For what use hath a man hands, and an ape also with is like unto a man?
The hand is an instrument which a man doth especially make use of, because many things are done by the hands, and not by any other part, as Aristotle doth teach.
Why are some men ambo dexter -- that is, use the left hand as the right?
By reason of the great heat of the heart, and for the hot bowing of the same, for it is that which makes a man as nimble of the left hand as of the right; and without doubt are of good complexions.
Why are not women ambo dexter as well as men? Hid. ult. Aphorism.
Because, as Galen saith, a woman in health, that is most hot, is colder than the coldest man in health; I say in health, for if she hath an ague she is accidentally hotter than a man.
Why are the fingers full of joints?
To be more fit and apt to receive, and keep the things received.
Why hath every finger three joints, and the thumb but two?
The thumb hath three, but the third is joined unto the arm, therefore is stronger than the other finger; and is called pollox a polleo, that is, to excel in strength.
Why are the fingers of the right hand nimbler than the fingers of the left, as Aegidius saith?
It proceedeth from the heat which doth predominate in those parts, which causeth great agility.
Why are the fingers thicker before meat than after, as Albertus saith?
According to the physicians, because a man which is fasting is full of bad humours and divers fumosities, which puff up the parts of the body, and the fingers also; but when those humours are expelled through meat, the fingers become more slender. And for the same reason, a man which is fasting is heavier than when he hath meat in his belly, as is most plain in fasters. Another reason may be given, that is, because that after meat the heat is deprived from the outward parts of the body into the inward, to help digestion, and the outward and external parts become slender; but after the digestion is made, the blood turneth again to exterior parts, and then they become great again.
Why are some men left handed?
Because the heart sendeth out heat into the right side but more into the left and doth also work a slenderness and subtility on the left side.