Nor is the blood to be styled the primigenial and principal portion of the body, because the pulse has its commencement in and through it; but also because animal heat originates in it, and the vital spirit is associated with it, and it constitutes the vital principle itself, (ipsa anima); for wheresoever the immediate and principal instrument of the vegetative faculty is first discovered, there also does it seem likely will the living principle be found to reside, and thence take its rise; seeing that the life is inseparable from spirit and innate heat.
For “however distinct are the artist and the instrument in things made by art,” as Fabricius[274] well reminds us, “in the works of nature they are still conjoined and one. Thus the stomach is the author and the organ of chylopoesis.” In like manner are the vital principle and its instrument immediately conjoined; and so, in whatever part of the body heat and motion have their origin, in this also must life take its rise, in this be last extinguished; and no one, I presume, will doubt that there are the lares and penates of life enshrined, that there the vital principle (anima) itself has its seat.
The life, therefore, resides in the blood, (as we are also informed in our sacred writings,)[275] because in it life and the soul first show themselves, and last become extinct. For I have frequently found, from the dissection of living animals, as I have said, that the heart of an animal that was dying, that was dead, and had ceased to breathe, still continued to pulsate for a time, and retained its vitality. The ventricles failing and coming to a stand, the motion still goes on in the auricles, and finally in the right auricle alone; and even when all motion has ceased, there the blood may still be seen affected with a kind of undulation and obscure palpitation or tremor, the last evidence of life. Every one, indeed, may perceive that the blood—this author of pulsation and life,—longest retains its heat; for when this is gone, and it is no longer blood, but gore, so is there, then, no hope of a return to life. But, truly, as has been stated, both in the chick in ovo and in the moribund animal, if you but apply some gentle stimulus either to the punctum saliens or to the right auricle of the heart after the failure of all pulsation, forthwith you will see motion, pulsation, and life restored to the blood—provided always, be it understood, that the innate heat and vital spirit have not been wholly lost.
From this it clearly appears that the blood is the generative part, the fountain of life, the first to live, the last to die, and the primary seat of the soul; the element in which, as in a fountain head, the heat first and most abounds and flourishes; from whose influxive heat all the other parts of the body are cherished, and obtain their life; for the heat, the companion of the blood, flows through and cherishes and preserves the whole body, as I formerly demonstrated in my work on the motion of the blood.
And since blood is found in every particle of the body, so that you can nowhere prick with a needle, nor make the slightest scratch, but blood will instantly appear, it seems as if, without this fluid, the parts could neither have heat nor life. So that the blood, being in ever so trifling a degree concentrated and fixed,—Hippocrates called the state ἀπύληψις τῶν φλεβῶν—stasis of the veins,—as in lipothymia, alarm, exposure to severe cold, and on the accession of a febrile paroxysm, the whole body is observed to become cold and torpid, and, overspread with pallor and livor, to languish. But the blood, recalled by stimulants, by exercise, by certain emotions of the mind, such as joy or anger, suddenly all is hot, and flushed, and vigorous, and beautiful again.
Therefore it is that the red and sanguine parts, such as the flesh, are alone spoken of as hot, and the white and bloodless parts, on the contrary, such as the tendons and ligaments, are designated as cold. And as red-blooded animals excel exsanguine creatures, so also, in our estimate of the parts, are those which are more liberally furnished with native heat and blood, held more excellent than all the others. The liver, spleen, kidneys, lungs, and heart itself,—parts which are especially entitled viscera,—if you will but squeeze out all the blood they contain, become pale and fall within the category of cold parts. The heart itself, I say, receives influxive heat and life along with the blood that reaches it, through the coronary arteries; and only so long as the blood has access to it. Neither can the liver perform its office without the influence of the blood and heat it receives through the cœliac artery; for there is no influx of heat without an afflux of blood by the arteries, and this is the reason wherefore, when parts are first produced, and before they have taken upon them the performance of their respective duties, they all look bloodless and pale, in consequence of which they were formerly regarded as spermatic by physicians and anatomists, and in generation it was usual to say that several days were passed in the milk. The liver, lungs, and substance of the heart itself, when they first appear, are extremely white; and, indeed, the cone of the heart and the walls of the ventricles are still seen to be white, when the auricles, replete with crimson blood, are red, and the coronary vein is purple with its stream. In like manner, the parenchyma of the liver is white, when its veins and their branches are red with blood; nor does it perform any duty until it is penetrated with blood.
The blood, in a word, so flows around and penetrates the whole body, and imparts heat and life conjoined to all its parts, that the vital principle, having its first and chief seat there, may truly be held as resident in the blood; in this way, in common parlance, it comes to be all in all, and all in each particular part.
But so little is it true, as Aristotle and the medical writers assert, that the liver and the heart are the authors and compounders of the blood, that the contrary even appears most obviously from the formation of the chick in ovo, viz.: that the blood is much rather the fashioner of the heart and liver; a fact, which physicians themselves appear unintentionally to confirm, when they speak of the parenchyma of the liver as a kind of effusion of blood, as if it were nothing more than so much blood coagulated there. But the blood must exist before it can either be shed or coagulated; and experience palpably demonstrates that the thing is so, seeing that the blood is already present before there is a vestige either of the body or of any viscus; and that in circumstances where none of the mother’s blood can by possibility reach the embryo, an event which is vulgarly held to occur among viviparous animals.
The liver of fishes is always perceived of a white colour, though their veins are of a deep purple or black; and our fowls, the fatter they become, the smaller and paler grows the liver. Cachectic maidens, and those who labour under chlorosis, are not only pale and blanched in their bodies generally, but in their livers as well, a manifest indication of a want of blood in their system. The liver, therefore, receives both its heat and colour from the blood; the blood is in no wise derived from the liver.
From what has now been said, then, it appears that the blood is the first engendered part, whence the living principle in the first instance gleams forth, and from which the first animated particle of the embryo is formed; that it is the source and origin of all other parts, both similar and dissimilar, which thence obtain their vital heat and become subservient to it in its duties. But the heart is contrived for the sole purpose of ministering between the veins and the arteries—of receiving blood from the veins, and, by its ceaseless contractions, of propelling it to all parts of the body through the arteries.