William Harvey

HARVEY, WILLIAM (1578-1657), English physician, the discoverer of the circulation of the blood, was born at Folke stone on April 1, 1578. He was educated at Caius college, Cam bridge, and then proceeded to Padua to study medicine under H. Fabricius and became doctor of medicine in April 1602. Return ing to England, he settled in London. He was admitted (June 1607) fellow of the Royal College of Physicians, and in 1609 obtained the reversion of the post of physician to St. Bartholo mew's hospital, and in the same year he succeeded to the post.

In 1616 he began a course of lectures at the College of Physi cians in which he first brought forward his views upon the move ments of the heart and blood. Meantime his practice increased, and he had the lord chancellor, Francis Bacon, and the earl of Arundel among his patients. He was physician extraordinary to James I., and physician in ordinary to Charles I. In 1628 he pub lished the Exercitatio anatomica de motu cordis et sanguinis; between 1629 and 1632 he travelled on the Continent, principally in Italy with James Stuart, afterwards duke of Richmond. Four years later he accompanied the earl of Arundel on his embassy to the emperor Ferdinand II. He returned to his practice in Lon don at the close of the year 1636, and accompanied Charles I. in one of his journeys to Scotland (1639 or 1641), and was in attend ance on the king at the battle of Edgehill (Oct. 1642), and then followed Charles I. to Oxford.

While with the king at Oxford he was made warden of Merton college, but a year later, in 1646, that city surrendered to Fairfax, and Harvey returned to London. He was now 68 years old, and, having resigned his appointments and relinquished the cares of practice, lived in learned retirement with one or other of his brothers. It was in his brother Daniel's house at Combe that Dr. (afterwards Sir George) Ent, a faithful friend and disciple (1604 89), visited him in 165o. The work on which he had been chiefly engaged at Oxford, and indeed since the publication of his trea tise on the circulation in 1628, was an investigation into the sub ject of generation. Charles I. had put the royal deer parks at Windsor and Hampton Court at his disposal, and had watched his demonstration of the growth of the chick with no less interest than the movements of the living heart. Harvey had collected a large number of observations, and Ent succeeded in obtaining the manuscripts, with authority to print them or not. The result was the publication of the Exercitationes de generations (1651).

This was the last of Harvey's labours. He had now reached his 73rd year. His theory of the circulation was generally accepted by the most eminent anatomists both in his own country and abroad and he was known arid honoured throughout Europe. In 1654 he was elected president of the College of Physicians but declined the honour, though he enriched the college with many gifts.

Harvey died on June 3, 1657, and was buried at Hempstead, Essex; in 1883 his remains were placed in the Harvey chapel in the church there.

John Aubrey says : "In person he was not tall, but of the low est stature; round faced, olivaster complexion, little eyes, round, very black, full of spirits; his hair black as a raven, but quite white 20 years before he died." The best known portrait of him extant is by Cornelius Jansen in the library of the College of Physicians.

Harvey's Work on the Circulation.

In estimating the character and value of the discovery announced in the Exercitatio de motu cordis et sanguinis, it is necessary to bear in mind the previous state of knowledge. Aristotle taught that the blood was elaborated from the food in the liver, thence carried to the heart, and sent through the veins over the body. The Alexandrian physi cians, Erasistratus and Herophilus, taught that, while the veins carried blood from the heart to the members, the arteries carried a subtle kind of air or spirit. Galen discovered that the arteries were not, as their name implies, mere air-pipes, but that they con tained blood as well as vital air or spirit and he believed that the nerves (vei pa) arose from the brain and conveyed "animal spirits" to the body. The views of Galen remained current till the 16th century. The physicians of that period had developed certain doctrines concerning the vascular system which we may thus sum marize : First, the blood is not stagnant, but moves in the body. But no one had a conception of a continuous stream returning to its source (a circulation in the true sense of the word) either in the system or in the lungs. If they used the word circulatio, as did Caesalpinus, it was as vaguely as the French policeman cries "Circulez." The movements of the blood were in fact thought to be slow and irregular in direction as well as in speed, like the "circulation" of air in a house, or of a crowd in the streets. Secondly, they supposed that one kind of blood flowed from the liver to the right ventricle of the heart, and thence to the lungs and the general system by the veins, and that another flowed from the left ventricle to the general system by the ar teries. Thirdly, they supposed that the septum of the heart was pervious and allowed blood to pass directly from the right to the left side. Fourthly, they had no conception of the functions of the heart as the motor power of the movement of the blood. They doubted whether its substance was muscular; they sup posed its pulsation, like that of the arteries, to be due to expansion of the contained spirits.

Of the great anatomists of the r6th century, Vesalius (De humani corporis fabrica, 1542) ascertained that the septum be tween the right and left ventricles is complete, though he could not bring himself to deny the invisible pores which Galen's sys tem demanded. Servetus, in his Christianismi restitutio goes somewhat farther, and, from this anatomical fact and the large size of the pulmonary arteries he concludes that there is a communication in the lungs by which blood passes from the pul monary artery to the pulmonary vein. It seems doubtful whether even Servetus rightly conceived of the entire mass of the blood passing through the pulmonary artery and the lungs. Indeed, a true conception of the lesser circulation as a transference of the whole blood of the right side to the left was impossible until the corresponding transference in the greater or systematic circula tion was discovered. Lastly, the system of valves in the veins had been elaborately set forth and illustrated by Harvey's own teacher Fabricius.

The way then to Harvey's great work had been paved by the discovery of the valves in the veins, and by that of the lesser cir culation, but the significance of the valves was unsuspected and the fact of even the pulmonary circulation was not generally admitted.

In his treatise Harvey proves (r) that it is the contraction, not the dilatation, of the heart which coincides with the pulse, and that the ventricles, as true muscular sacs, squeeze the blood which they contain into the aorta and pulmonary artery ; (2) that the pulse is produced by the arteries being filled with blood; (3) that there are no pores in the septum of the heart, so that the whole blood in the right ventricle is sent to the lungs and round by the pulmonary veins to the left ventricle, and also that the whole blood in the left ventricle is again sent into the arteries, round by the smaller veins into the venae cavae, and by them to the right ventricle again—thus making a complete "circulation"; (4) that the blood in the arteries and that in the veins is the same blood ; (5) that the action of the right and left sides of the heart, auricles, ventricles and valves, is the same, the mechanism in both being for reception and propulsion of liquid and not of air; (6) that the blood propelled through the arteries to the tissues is not all used, but that most of it runs through into the veins; (7) that there is no to-and-fro undulation in the veins, but a constant stream from the distant parts towards the heart; (8) that the dynamical starting-point of the blood is the heart and not the liver.

The method by which Harvey arrived at his solution of the most fundamental and difficult problem in physiology is well worthy of attention. He had not only furnished himself with all the knowledge that books and the instructions of the best anat omists of Italy could give, but, by a long series of dissections, had gained a far more complete knowledge of the comparative anat omy of the heart and vessels than any contemporary. Thus equipped, he tells us that he began his investigations into the movements of the heart and blood by seeing their action in living animals. He minutely describes what he saw and handled in dogs, pigs, serpents, frogs and fishes, and even in slugs, oysters, lob sters and insects, in the transparent shrimp, and lastly in the chick while still in the shell. He particularly describes his observations and experiments on the ventricles, the auricles, the arteries and the veins. He shows how the arrangement of the vessels in the foetus supports his theory. He adduces facts observed in dis ease as well as in health to prove the rapidity of the circulation. He explains how the mechanism of the valves in the veins is adapted to favour the flow of the blood to the heart. He esti mates the capacity of each ventricle, and reckons the rate at which the whole mass of blood passes through it. He elaborately and clearly demonstrates the effect of obstruction of the blood stream in arteries or in veins, by the forceps in the case of a snake, by a ligature on the arm of a man, and illustrates his argu ment by figures. These results can only be explained by the con stant circulation of the same blood. Lastly, in the r 5th, r6th and r 7th chapters, he adds certain confirmatory evidence, as to the effect of position on the circulation, the absorption of animal poisons and of medicines applied externally, the muscular struc ture of the heart and the necessary working of its valves. The whole treatise, which occupies only 52 pages of print, is a model of accurate observation, patient accumulation of facts, ingenious experimentation, cautious hypothesis and logical deduction.

In one point only was the demonstration of the circulation in complete. Harvey did not see the capillary channels by which the, blood passes from the arteries to the veins. This gap in the circulation was supplied thirty years later by the great anatomist Marcello Malpighi, who described the capillary circulation four years after Harvey's death. But the existence of the channels first seen by Malpighi was already clearly pointed to by Harvey's reasoning.

Harvey's Work on Generation.

The Exercitationes de generatione is between five and six times as long as the Exerc. de motu cord. et sang., and is followed by excursus De partu, De uteri membranis, De conceptions; but, though the fruit of as patient and extensive observations, its value is far inferior. The subject was more abstruse, and inaccessible to proper investiga tion without the aid of the microscope. Fabricius, Harvey's mas ter, in his work De formatione ovi et pulli (r 62 r) and another pupil of Fabricius, Volcher Coiter (1534–?) of Nuremberg, were among the few who had preceded Harvey in modern times. The 72 chapters which form the book lack the co-ordination so con spicuous in the earlier treatise, and some of them seem almost like detached chapters of a system which was never completed or finally revised.

Aristotle had believed that the male parent determined the form of the future embryo, while the female only nourished and nursed the seed. Galen taught that each parent contributes seeds, the union of which produced the young animal. Harvey, after speaking with due honour of Aristotle and Fabricius, begins "ab ovo," for he says, "almost all animals, even those which bring forth their young alive, and man himself, are produced from eggs." This dictum, usually quoted as omne vivum ex ovo, was a pre vision of genius, and was not proved until K. E. von Baer dis covered the mammalian ovum in 1827. Harvey proceeds with a careful anatomical description of the ovary and oviduct of the hen, describes the new-laid egg, and then gives an account of the appearance seen on the successive days of incubation. Comment ing on Aristotle and Fabricius, he declares against spontaneous generation, proves that there is no semen foemineum, that the chalazae of the hen's eggs are not the semen galli, and that both parents contribute to the formation of the egg. He describes accurately the first appearance of the ovarian ova as mere specks, their assumption of yolk and afterwards of albumen. He describes two methods of production of the embryo from the ovum: one is metamorphosis, or the direct transformation of pre-existing mate rial, as a worm from an egg, or a butterfly from an aurelia (chrysalis) ; the other is epigenesis, or development with addi tion of parts, the true generation observed in all higher animals. Chapters xlvi.–l. are devoted to the abstruse question of the efficient cause of generation, which, after much discussion of the opinions of Aristotle and of Sennertus, Harvey refers to the action of both parents as the efficient instruments of the first great cause. He then goes on to describe the order in which the several parts appear in the chick. He states that the punctum saliens or foetal heart is the first organ to be seen, and explains that the nu trition of the chick is not only effected by yelk conveyed directly into the midgut, as Aristotle taught, but also by absorption from yelk and white by the umbilical (omphalomeseraic) veins; on the fourth day of incubation appear two masses (which he oddly names vermiculus), one of which develops into three vesicles, to form the cerebrum, cerebellum and eyes, the other into the breast bone and thorax; on the sixth or seventh day come the viscera, and lastly, the feathers and other external parts. Harvey points out how nearly this order of development in the chick agrees with what he had observed in mammalian and particularly in human embryos. He notes the bifid apex of the foetal heart in man and the equal thickness of the ventricles, the soft cartilages which represent the future bones, the large amount of liquor amnii and absence of placenta which characterize the foetus in the third month ; in the fourth the position of the testes in the abdomen, and the uterus with its Fallopian tubes resembling the uterus bicornis of the sheep; the large thymus; the caecum, small as in the adult, not forming a second stomach as in the pig, the horse and the hare ; the lobulated kidneys, like those of the seal ("vitulo," sc. 'marina) and porpoise, and the large suprarenal veins, not much smaller than those of the kidneys (li.-lvi.) . He failed, however, to trace the connection of the urachus with the bladder. In the f ol lowing chapters (lxiii.-lxxii.) he describes the process of genera tion in the fallow deer or the roe. Much of Harvey's work on generation was superseded during the next 25 years by that of Malpighi. The remaining writings of Harvey are unimportant.

Of Harvey as a practising physician we know very little. Aubrey tells us that "he paid his visits on horseback with a f oot cloth, his man following on foot, as the fashion then was." He adds—"Though all of his profession would allow him to be an excellent anatomist, I never heard any that admired his thera peutic way. I knew several practitioners that would not have given threepence for one of his bills" (the apothecaries used to collect physicians' prescriptions and sell or publish them to their own profit), "and that a man could hardly tell by his bill what he did aim at." However this may have been, and rational thera peutics was impossible when the foundation stone of physiology had only just been laid, we know that Harvey was an active prac titioner, performing such important surgical operations as the removal of a breast, and he turned his obstetric experience to account in his book on generation. Some good practical precepts as to the conduct of labour are quoted by Percivall Willughby (1596-1685) . He also took notes of the anatomy of disease ; these unfortunately perished with his other manuscripts. We may re gard him as a forerunner of Morgagni, for Harvey saw that path ology is but a branch of physiology, and like it must depend on accurate anatomy. He speaks to this purpose in his first epistle to Riolan. The only specimen we have of his observations in morbid anatomy is his account of the post-mortem examination made by order of the king on the body of the famous Thomas Parr, who died in 1635, at the reputed age of 552. Harvey insists on the value of physiological truths for their own sake, independently of their immediate utility; but he himself gives us an interesting example of the practical application of his theory of the circula tion, in the cure of a large tumour by tying the arteries which sup plied it with blood (De generat. Exerc., xix.) .

BIBLIOGRAPHY.-The

following is believed to be a complete list of Bibliography.-The following is believed to be a complete list of all the known writings of Harvey, published and unpublished: Exercitatio anatomisa de motu Gordis et sanguinis, (Frankfort-on Main, 1628) ; Exercitationes duae anatomicae de circulatione sanguinis, ad Johannem Riolanum, filium, Parisiensem (Cambridge, 1649) ; Exer citationes de generatione animalium, quibus accedunt quaedam de partu, de membranes ac humoribus uteri, et de conceptione (1651) ; Anatomia Thomae Parr, first published in the treatise of Dr. John Betts, De ortu et natura sanguinis (1669) . Letters: To Caspar Hoff mann of Nuremberg, May 1636; to Schlegel of Hamburg, April 1651 ; three to Giovanni Nardi of Florence, July 1651, Dec. 1653, and Nov. 1655 ; two to Dr. Morison of Paris, May 1652 ; two to Dr. Horst of Darmstadt, Feb. 1654-55 and July 1655 ; to Dr. Vlackveld of Haarlem, May 165 7. His letters to Hoffman and Schlegel are on the circula tion ; those to Morison, Horst and Vlackveld refer to the discovery of the lacteals ; the two to Nardi are short letters of friendship. All these letters were published by Sir George Ent in his collected works (Ley den, 1687) . Of two ms. letters, one, on official business to the secre tary, Dorchester, was printed by Dr. Aveling, with a facsimile of the crabbed handwriting (Memorials of Harvey, 1875), and the other, about a patient, appears in Dr. Robert Willis's Life of Harvey (1878) . Praelectiones anatomise universalis per me Gul. Harveium medicum Londinensem, anat. et chir. professorem, an. dom. (1616), aetat. ms. notes of his Lumleian lectures in Latin—are in the British Museum library ; an autotype reproduction was issued by the College of Physi cians in 1886. An account of a second ms. in the British Museum, en titled Gulielmus Harveius de musculis, motu locali, etc., was published by Sir G. E. Paget (Notice of an unpublished ms. of Harvey, 185o) . The following treatises, or notes towards them, were lost either in the pillaging of Harvey's house, or perhaps in the Fire of London, which destroyed the old College of Physicians: A Treatise on Respiration, promised and probably at least in part completed (pp. 82, 55o, ed. 1766) ; Observationes de usu Lienis; Observationes de motu locali, perhaps identical with the above-mentioned manuscript; Tractatum physiologicum; Anatomia medicalis (apparently notes of morbid anatomy) ; De generatione insectorum. The fine edition of Harvey's Works, published by the Royal College of Physicians in 1766, was superintended by Dr. Mark Akenside ; it contains the two treatises, the account of the post-mortem examination of old Parr, and the six letters enumerated above. A translation of this volume by Dr. Willis, with Harvey's will, was published by the Sydenham Society (1847) .

A copy of the De generatione with numerous notes in Harvey's own hand, referring chiefly to his reading of Aristotelian works, is in private possession.

There is a convenient photographic facsimile of the work on the circulation issued by C. Moreton (1894) . The standard translation of his collected works is still that of Thomas Willis (1847) . A con venient reprint of the translation Willis of the work on the circula tion is available (1906).

The literature that has arisen on Harvey and his great discovery would fill a library. A bibliography by Geoffrey Keynes has been published (1928) , and a further account of the works of Harvey on the occasion of the celebration of the tercentenary of the publica tion of the work on the circulation by the Royal College of Physicians, London (1928) . Of recent writings on Harvey mention may be made of the life by D'Arcy Power (1897) ; the facsimile of Harvey's Paduan diploma issued by the Royal College of Physicians, with pamphlet by J. F. Payne (1908) ; the volume of Portraits of Harvey published by the Historical Section of the Royal Society of Medicine (1913) . The Harveian oration at the Royal College of Physicians is devoted to an annual exposition of some part of his work. Among the recent orations are those by W. Osler, The Growth of Truth (1906) ; H. R. Spencer, William Harvey, Obstetric Physician and Gynaecologist (1921) ; A. Chaplin, Medicine in the Century before Harvey (1922) ; C. Singer, Discovery of the Circulation of the Blood (192 2) gives an exposition of the history of this event.

(P. H. P. S.; C. Sr.)