William Harvey

by Sir D'Arcy Power

“But in some of the pale-blooded and colder animals, as in snails, whelks, shrimps, and shell-fish, there is a part which pulsates—a kind of vesicule or auricle without a heart—slowly, indeed, and not to be perceived except in the warmer season of the year.... In fishes, serpents, lizards, tortoises, frogs, and others of the same kind there is a heart present, furnished with both an auricle and a ventricle.... And then in regard to animals that are yet larger and warmer and more perfect,... these require a larger, stronger, and more fleshy heart.... Every animal that has lungs has two ventricles to its heart, one right, the other left, and whenever there is a right there is a left ventricle, but the contrary does not hold good; where there is a left there is not always a right ventricle.... It is to be observed, however, that all this is otherwise in the embryo where there is not such a difference between the two ventricles.... Both ventricles also have the same office to perform, whence their equality of constitution. It is only when the lungs come to be used ... that the difference in point of strength and other things between the two ventricles becomes apparent. In the altered circumstances the right has only to drive the blood through the lungs, whilst the left has to propel it through the whole body.”

This concludes Harvey’s Demonstration of the Circulation of the Blood in 1628, but he continued to work at the subject throughout his life. In two letters or anatomical disquisitions, addressed to the younger Riolanus of Paris, and dated from Cambridge in 1649, Harvey gives his latest reflections upon the subject of the Circulation of the Blood. These disquisitions differ very greatly from the original treatise. They are less clear and concise, and dwell more upon points of dispute which had arisen in connection with the controversy, which raged for many years round Harvey’s discovery.

The first disquisition is devoted more especially to the question of the anastomosis which takes place between the arteries and the veins, whilst the second disquisition illustrates more fully a number of details connected with the nature and quantity of the blood and its mode of progression. Harvey says incorrectly of the anastomosis, “Neither in the liver, spleen, lungs, kidneys, nor any other viscus, is such a thing as an anastomosis to be seen, and by boiling I have rendered the whole parenchyma of these organs so friable that it could be shaken like dust from the fibres or picked away with a needle, until I could trace the fibres or every sub-division, and see every capillary filament distinctly. I can, therefore, boldly affirm that there is neither any anastomosis of the vena portæ with the cava, of the arteries with the veins, or of the capillary ramifications of the biliary ducts, which can be traced through the entire liver, with the veins.”

The second disquisition opens with Harvey’s view of the contemporary criticism upon his treatise. “But scarce a day, scarce an hour has passed since the birthday of the Circulation of the blood that I have not heard something, for good or for evil, said of this, my discovery. Some abuse it as a feeble infant, and yet unworthy to have seen the light; others again think the bantling deserves to be cherished and cared for. These oppose it with much ado, those patronise it with abundant commendation. One party holds that I have completely demonstrated the circulation of the blood by experiment, observation, and ocular inspection against all force and array of argument; another thinks it scarcely sufficiently illustrated—not yet cleared of all objections. There are some, too, who say that I have shown a vainglorious love of vivisections, and who scoff at and deride the introduction of frogs and serpents, flies, and other of the lower animals upon the scene, as a piece of puerile levity, not even refraining from opprobrious epithets.

“To return evil speaking with evil speaking, however, I hold to be unworthy in a philosopher and searcher after truth. I believe that I shall do better and more advisedly if I meet so many indications of ill breeding with the light of faithful and conclusive observation. It cannot be helped that dogs bark and vomit their foul stomachs, or that cynics should be numbered among philosophers; but care can be taken that they do not bite or inoculate their mad humours, or with their dogs’ teeth gnaw the bones and foundations of truth.

“Detractors, mummers, and writers defiled with abuse, as I resolved with myself never to read them, satisfied that nothing solid or excellent, nothing but foul terms was to be expected from them, so have I held them still less worthy of an answer. Let them consume on their own ill-nature. They will scarcely find many well-disposed readers, I imagine, nor does God give that which is most excellent, and chiefly to be desired—wisdom—to the wicked. Let them go on railing, I say, until they are weary, if not ashamed.”

Amidst a mass of unprofitable speculation, the second Disquisition contains one or two gems of pathological observation, illustrating physiological conclusions. Desiring to set in a clear light “that the pulsific power does not proceed from the heart by the coats of the vessels, I beg here to refer to a portion of the descending aorta, about a span long in length, with its division into two crural trunks, which I removed from the body of a nobleman, and which is converted into a bony tube: by this hollow tube nevertheless, did the arterial blood reach the lower extremities of this nobleman during his life, and cause the arteries in these to beat.... Where it was converted into bone it could neither dilate nor contract like bellows, nor transmit the pulsific power from the heart to the inferior vessels: it could not convey a force which it was incapable of receiving through the solid matter of the bone. In spite of all, however, I well remember to have frequently noticed the pulse in the legs and feet of this patient whilst he lived, for I was myself his most attentive physician, and he my very particular friend. The arteries in the inferior extremities of this nobleman must, therefore, and of necessity, have been dilated by the impulse of the bloodlike flaccid sacs, and not have expanded in the manner of bellows through the action of their tunics.

“I have several times opened the breast and pericardium of a man within two hours after his execution by hanging, and before the colour had totally left his face, and in presence of many witnesses, have demonstrated the right auricle of the heart and the lungs distended with blood: the auricle in particular of the size of a large man’s fist, and so full of blood that it looked as if it would burst. This great distension, however, had disappeared next day, the body having stiffened and become cold, and the blood having made its escape through various channels.

“I add another observation. A noble knight, Sir Robert Darcy, an ancestor of that celebrated physician and most learned man, my very dear friend, Dr. Argent, when he had reached to about the middle period of life, made frequent complaint of a certain distressing pain in the chest, especially in the night season, so that dreading at one time syncope, at another suffocation in his attacks, he led an unquiet and anxious life. He tried many remedies in vain, having had the advice of almost every medical man. The disease going on from bad to worse, he by and by became cachectic and dropsical, and finally grievously distressed, he died in one of his paroxysms. In the body of this gentleman, at the inspection of which there were present Dr. Argent, the President of the College of Physicians, and Dr. Gorge, a distinguished theologian and preacher, who was pastor of the parish, we found the wall of the left ventricle of the heart ruptured, having a rent in it of size sufficient to admit any of my fingers, although the wall itself appeared sufficiently thick and strong. This laceration had apparently been caused by an impediment to the passage of the blood from the left ventricle into the arteries.