Of the Heart.
Why are the heart and dugs called lively parts of the body, in Latin, Spirituala membrana?
From the word Spiritus, which signifies breath, life, or soul; and because the vital spirits are engendered in the brain. Yet that is no good answer, for the liver and brain might be so called, because the liver giveth nutriment, and the brain sense and life; the consequence is clear, for the vital spirits are engendered in the liver, and the sensible and animal spirits in the brain.
Why are the lungs light, spungy, and full of holes?
That the air may the better be received in them for cooling the heart, and expelling humours, because the lungs are the fan of the heart; and as a pair of bellows is railed up by taking in the air, and shrink by blowing it out, so likewise the lungs draw the air to cool the heart and cast it out, lest through too much heat of the air drawn in the heart should be suffocated.
Why is the flesh of the lungs white?
Because they are in continual motion.
Why have those beasts only lungs that have hearts?
Because the lungs be no part for themselves, but for the heart; and therefore it were superfluous for those creatures to have lungs that have no hearts; but nature is never wanting in things necessary, nor abounds in superfluities.
Why do such creatures as have no lungs want a bladder?
Because such drink no water to make their meat digest, but only for the tempering their food, and therefore they want a bladder and urine: as appears in such birds as do not drink at all, viz., the falcon and sparrow-hawk.
Why is the heart in the midst of the body?
Because it should impart life to all parts of the body, and therefore it is compared to the sun, which is placed in the midst of the planets, to pour light into them all; therefore the Pythagoreans styling the heavens a great living creature, say the sun is the heat thereof.
Why only in men is the heart on the left side?
To the end the heat of the heart should mitigate the coldness of the spleen, for the spleen is the seat of melancholy, which is on the left side also.
Why is the heart first engendered; for according to Aristotle, the heart doth first live, and die last?
Because, as Aristotle saith, de juvent. and fenect., the heart is the beginning and original of life, and without it no part can live. According to the philosopher, of the seed retained in the matrix there is first engendered a little small skin, which compasses the seed wherefore first the heart is made of the purest blood; then of blood not so pure, the liver; and of thick and cold blood, the marrow and brain.
Why are beasts bold that have little hearts?
Because in a little heart the heart is well united and vehement, and the blood touching it, doth quickly heat it, and is speedily carried to other parts of the body, which gives courage and boldness.
Why are creatures with a large heart timorous, as the hare?
The heart is dispersed in such a one, and not able to heat the blood which cometh to it, and so fear is bred.
How comes it that the heart is continually moving?
According to Aristotle de motu cordis, and Galen, it is because in it there is a certain spirit which is more subtile than air, which by reason of its thickness and rarefaction marks a larger space, filling the hollow room of the heart, whereof the dilating and opening of the heart doth follow; and because the heart is earthly the thrusting and moving ceasing, its parts are at rest, tending downwards. Galen giveth an experiment of an acorn, which, if put into the fire, the heat dissolves its humidity, therefore doth occupy a greater space, so that the rind cannot contain it, but puffs it up and throws it into the fire. The like of the heart; therefore note, that the heart of a living creature is triangular in a manner, having its least part towards the left side, and the greater towards the right, and doth also open and shut in the least part, by which means it is a continual motion; the first motion is by the physicians called Diastole, that is, extending the breast or heart; the other Systole, i.e., shutting of the heart; and from these two all the motions of the body proceed, and that of the pulse which physicians feel.
Why are great beasts lean?
The natural heat proceeding from the heart consumes that natural humidity which should be converted into fat. And for the most part women are hotter than men, because they have much humidity in them, and a moister heart than men.
How comes it that the flesh of the heart is so compact and knit together?
It is because in thick compacted substances heat is strongly received and united, as appears in other things; And because the heart with its heat should moderate the coldness of the brain, it is made of that fat flesh apt to keep a strong heat.
How comes the heart to be the hottest part of all living creatures?
It is so compacted as to receive heat best and because it should mitigate the coldness of the brain.
Why is the heart the beginning of life?
It is plain in it the vital spirit is bred, which is the heat of life; and therefore according to the opinion of August, de different. spirit. et anima, the heart hath two receptacles, i.e., the right and the left; the right hath more blood than spirits, which spirit is engendered, to give life and vivify the body.
Why is the heart long and sharp like a pyramid?
The round figure hath no angles, therefore the heart is round, for fear any poison or hurtful matter should be retained in it and as Aristotle affirms, because that figure is fittest for motion.
How comes the blood chiefly to be in the heart?
The blood is in the heart as in its proper or efficient place, which some attribute to the liver; and therefore the heart doth not receive blood of any other parts, but no other parts of it.
How happens it that some creatures want a heart?
Although they have no heart, yet they have somewhat that answers it, as appears in eels, and fish which have the back-bone instead of a heart.
Why does the heart beat in some creatures when the head is off, as appears in birds and hens?
Because the heart is what lives first and dies last, and therefore beats more than other parts.
Why doth the heat of the heart sometimes fall of a sudden, as in those who have the falling sickness?
This proceeds, according to Constant, from a defect of the heart itself, and of certain small skins with which it is covered, the which being infected and corrupted the heart falleth of a sudden; and sometimes it happen by reason of the parts adjoining, and therefore, when any venomous humour goes out of the stomach, that hurts the heart and parts adjoining, that causes this fainting; the disposition of the heart is known by the pulse, because a swift beating pulse shows the heat of the heart, and a slow beating one denotes coldness. Therefore a woman that is in health has a slower and weaker pulse than a man, as shall appear hereafter.