The Works of William Harvey M.D. / Translated from the Latin with a life of the author

by William Harvey

ON THE HEART AND BLOOD.

Harvey’s great work, though by no means the largest in bulk, is the one on the Motions of the Heart and Blood. It has been said, happily, by a recent critical writer, that “men were already practising what Bacon came to inculcate,” viz. induction upon data carefully collected and considered; and it would not be easy to adduce a more striking example of the way in which ultimate rational truth is arrived at by a succession of inferences than is contained in Harvey’s Essay on the Heart and Blood. Had Bacon written his Novum Organum from Harvey’s work as a text, he would scarcely have expressed himself otherwise than as he has done, or given different rules for philosophizing than those which he has laid down in his celebrated treatise.[28]

In his introduction, and by way of clearing the ground, Harvey exposes the views of preceding physiologists, ancient and modern, in regard to the motions of the heart, lungs, and blood, to the state of the arteries, &c.—in short, he gives the accredited physiology of the thoracic viscera, with comments, which prove it a mass of unintelligible and irreconcilable confusion. There is room, therefore, for another interpretation, consonant with reason and with anatomical fact, and susceptible of demonstration by the senses. When he first essayed himself to comprehend the motions of the heart, and to make out the uses of the organ from the dissection of living animals, he found the subject so beset with difficulties that he was almost inclined at one time to say with Fracastorius, that these motions and their purpose could be comprehended by God alone. By degrees, however, by repeating his observations, using greater care, and giving more concentrated attention, he at last discovers a way out of the labyrinth, and a means of explaining simply all that had previously appeared so obscure. Hence the occasion of his writing. Such is the burthen of the proem and first chapter. With Harvey’s admirable work now put in an accessible shape into his hands, we should (did we proceed with an analysis) but anticipate the intelligent reader in the great pleasure he will have in following the author through the different steps of his argument until the conclusion is reached, and the inference presents itself as inevitable, namely, that the blood must circle round and round in one determinate course, in the body as in the lungs, incessantly. For Harvey, it must be here observed, left the doctrine of the circulation as an inference or induction only, not as a sensible demonstration. He adduced certain circumstances, and quoted various anatomical facts which made a continuous transit of the blood from the arteries into the veins, from the veins into the arteries, a necessary consequence; but he never saw this transit; his idea of the way in which it was accomplished was even defective; he had no notion of the one order of sanguiferous vessels ending by uninterrupted continuity, or by an intermediate vascular network, in the other order. This was the demonstration of a later day, and of one who first saw the light in the course of the very year when Harvey’s work on the Heart was published.[29]

The appearance of Harvey’s book on the Motion of the Heart and Blood seems almost immediately to have attracted the attention of all the better intellects among the medical men of Europe. The subject was not one, indeed, greatly calculated to interest the mass of mere practitioners; had it been a book of receipts it would have had a better chance with them; but the anatomists and physiologists and scientific physicians would seem at once to have taken it up and canvassed its merits. The conclusions come to in the work, there can be no question, took the medical world by surprise; it was not prepared for such a proposition as a ceaseless circular movement of the blood, with the heart for the propelling organ; for the latter point, be it understood, was even as great a novelty as the former.

Coming unexpectedly, and differing so widely from the ancient and accepted notions, we cannot wonder that Harvey’s views were at first rejected almost universally. The older intellects, in possession of the seats and places of authority, regarded them as idle dreams; and upon the faith of this conclusion, their author was set down and treated by the vulgar as a crackbrained innovator. Two years, however, elapsed before aught in contravention of the new doctrines saw the light, and this came at length not from any of the more mature anatomists of Europe—their minds were made up, the thing was absurd—but from a young physician, of the name of Primerose, of Scottish descent, but French by birth. Primerose had been a pupil of Joannes Riolanus, professor of anatomy in the University of Paris; he had doubtless listened to his master’s demonstration of the absurdity of the Harveian doctrine of the circulation, and by and by he set himself down, by way apparently of exercising his ingenuity, to try the question, not by fact and experiment, but by the precepts he had imbibed from his teacher and the texts of the ancients. The essay of Primerose[30] may be regarded as a defence of the physiological ideas of Galen against the innovations of Harvey. It is remarkable for any characteristic rather than that of a candid spirit in pursuit of truth; it abounds in obstinate denials, and sometimes in what may be termed dishonest perversions of simple matters of fact, and in its whole course appeals not once to experiment as a means of investigation.—Harvey, having already, and in the very outset of his work, demonstrated the notions untenable which it was Primerose’s purpose to reassert and defend, of course deigned him no reply; he could never dream of going over the barren ground he had already trodden, in the hope of convincing such an antagonist.

Æmylius Parisanus, a physician of Venice, was the next to assail the Harveian doctrine of the circulation,[31] and still with the old instruments,—the authority of Galen and the ancients generally. Parisanus perceived Harvey’s views as directly contravening an hypothesis to which he had formerly committed himself, namely, that the spleen was the organ of sanguification and the furnisher of nutriment to the heart; on this ground may Parisanus have been led to enter the lists against the new opinions. But he proved a most flimsy antagonist. Ignorant of some of the commonest points of anatomy, and frequently misinterpreting the writer he combats, writing himself in a style the most elaborately involved, and consequently obscure, it is frequently difficult even to guess at his meaning. Like his countryman of the poet, Signor Gratiano, he

“Speaks an infinite deal of nothing; more than any man in all Venice: his reasons are two grains of wheat hid in two bushels of chaff; you shall seek all day ere you find them; and when you have them they are not worth the search.”

Had not Dr. Ent, in his Apology for the Circulation, given the name a place on his title-page, Parisanus’s opposition would scarcely have merited mention here.

Nearly at the same time with Parisanus, Caspar Hofmann, the learned and laborious professor of Nuremberg, attracted particular attention, both in his teaching and his writings, as the opponent of the Harveian doctrine. The opposition here is the more remarkable from Hofmann’s having shaken himself wholly free from the authority of Galen, and, as Slegel says, even admitted the lesser circulation of the blood through the lungs; but this must have been at a later period of his life, for in his works, up to Harvey’s time, the idea he had of the motion of the blood may be gathered from his likening it to a lake or sea agitated by the wind, the veins being the conduits of the nutrient blood, the arteries of the vital spirits. Hofmann was an adversary whom Harvey held worthy of notice; and accordingly we have seen that our immortal countryman took advantage of the opportunity, whilst attending the Earl of Arundel and his party, to visit Hofmann at Nuremberg, and make a demonstration of the new views before him. Unhappily this was done in vain, for Hofmann continued unconvinced, though, towards the end of his very long life, he did show some signs of yielding.[32]

Joannes Veslingius, professor in the University of Padua, and one of the best anatomists of the age, about this time, addressed two letters to Harvey, in which he politely but candidly states his objections to the new doctrine. One great difficulty with Veslingius was the remarkable difference between the colour of the arterial and the venous blood. It did not seem possible to him that the fluid, which was of a bright scarlet in the arteries, could be the same as the dark-coloured fluid which is found in the veins. In the course of his letter, Veslingius takes occasion to animadvert on the uncivil tone and indifferent style of the productions of Primerose and Parisanus.[33]

But the theory of the double circulation was not now to meet with opposition only; the comprehensive intellect that had seized and worked that theorem to a rational demonstration was no longer to be left alone against the world in its defence. Roger Drake, a young Englishman, had the honour of appearing in his inaugural dissertation, proposed under the auspices of Joannes Walæus, the distinguished professor of Leyden, in 1639, as the enlightened advocate of the Harveian views; and in the course of the same year, H. Regius (Leroy) also came forward at Utrecht with certain Theses favorable to the doctrine of the circulation. Ten years had not lessened Primerose’s enmity to Harvey and his views; for, on the appearance of these academical essays, he speedily showed himself again in the field as their opponent, publishing distinct animadversions upon each of the inaugural dissertations in the course of the year.[34] Regius (Leroy), a man of much less mind and information than Drake, if we may decide from their works, was, in turn, not slow to encounter Primerose;[35] and the spirit in which he did so, as well as the temper and taste of the reply which Primerose, true to his controversial nature, very soon produced,[36] may, to a certain extent, be imagined from the titles of their several productions, which are given below.

Still more illustrious advocates of the Harveian circulation presented themselves in Werner Rolfink,[37] professor of anatomy at Jena, and the celebrated Renatus Descartes. Rolfink, from his position and his popularity as a teacher, had immense influence in disseminating the new doctrine over Europe; and Descartes, under the ægis of his powerful name, was no less effective by means of his writings.[38] Opposed in his advocacy of the Harveian views by Vopiscus Fortunatus Plempius, professor of Louvain, Descartes made himself still more thoroughly master of the subject, and when he next appears as its advocate, which he does by and by, he even appeals to the experiments he had made on living animals in support of his convictions and conclusions.

The controversy on the circulation had been carried on up to this time abroad rather than at home; Harvey seems to have won over to his side all the men of his own country who, by their education and acquirements, might have been fitted to array themselves against him: his lectures at the College of Physicians had apparently satisfied all his contemporaries. But now one of Harvey’s own countrymen made his appearance as the vindicator of the circulation from the misrepresentations and misapprehensions of its adversaries. This was Dr. afterwards Sir George Ent, a good scholar, a respectable anatomist, conversant with physical science generally, a gentleman by his position and profession, acquainted with all the leading men of letters and science of his time, and in particular, enjoying the friendship of William Harvey. Ent’s work is entitled ‘An Apology for the Circulation of the Blood, with a Reply to Æmylius Parisanus.’[39] In his letter to Harvey, which stands in front of the work, Ent lets it appear that he was anxious to come before the world as the advocate of the circulation; he first thought of making Primerose the particular object of his animadversions, but as this opponent had already been very effectually handled by Henry Leroy, he preferred taking Parisanus to task, the rather as in dealing with him he could also controvert Primerose where it was necessary.—Ent’s Apology is, undoubtedly, a learned, though perhaps a somewhat pompous and pedantic book; still the writer occasionally shows both wit and fancy in handling his antagonist, and always learning enough in dealing with his subject. “Nothing, indeed,” to quote Dr. Lawrence,[40] “can be more unlike than Parisanus and Ent; and it is not wonderful, therefore, that one utterly ignorant of physical science confronted by one thoroughly conversant therein—that one, without power of utterance, opposed by one gifted with eloquence—that one, sluggish and inert, in the hands of one active and full of energy, should be effectually vanquished and overcome.” We may imagine, nay, we may be certain, that Harvey was not unacquainted with Ent’s purpose to appear as the advocate of his discovery, nor with the Apology before it saw the light.

Having observed the appearance of certain academical dissertations in defence of the circulation, we perceive the apostles of all new truths, namely, the youthful, at work. Were there not successive generations of men, the world would stand still; the death of the individual was not merely a necessary condition to the enjoyment of life by successive generations, but essential also to the onward progress of mankind. No man who had attained to the age of 40 years, it is said, was found to adopt the doctrine of the circulation; it had to win its way under the safeguard of the Drakes and Leroys especially, that is to say, of the youthful and unprejudiced spirits of the age.

Twenty years after the publication of the ‘Exercitatio de Motu Cordis et Sanguinis,’ Joannes Riolanus, the younger, was delivered of his ‘Encheiridium Anatomicum’ (8vo. Lugd. Batav. 1648), in which he makes a vain attempt to supplant the Harveian doctrine by a new and most extraordinary one of his own, so incongruous and unlikely, that in these days we are irresistibly led to form no very high estimate of the intellect that could have engendered it. It looks to us, indeed, at this time, like condescension on the part of the great English anatomist, that he noticed the abortion of such a tyro in animal physics as the French professor here approves himself. Harvey’s genius could surely have felt no real respect for the illogical intellect of Riolan. But Harvey, when he noticed Riolan’s publication, was in want of a good occasion for a farther development of his own views; and so he seized on the Parisian professor, respectable from his position in the university, and as physician to the queen mother of France, and made him his vehicle—his placard bearer. Harvey, besides, was personally acquainted with Riolan, who had accompanied Mary de Medicis to England on a visit to her daughter the Queen of Charles the First; on which occasion Harvey and Riolan had even held conversations on the subject of the circulation, to which it is said that Riolan when face to face with the propounder, made no objection.

Riolan is by no means totally opposed to a circulation of the blood; he would only limit it to certain arbitrary regions, into which he divides the body: whilst it goes forward in one, it has no existence in another. The nature of his ideas can be gathered from Harvey’s comments on them in his First Disquisition, addressed to the Coryphæus of Anatomists, as he politely designates the Parisian professor.

Having disposed of the original notions of the author of the ‘Encheiridium Anatomicum,’ in this first disquisition, Harvey, in his second, returns to his own views, which he proceeds still further to illustrate and confirm by additional arguments, observations, and experiments. In this admirable essay, we obtain innumerable glimpses of the clearness of Harvey’s judgment, of his admirable powers of observation, and the diligent and excellent use he made of them; we at the same time become aware of the great loss we have sustained through the destruction of his Medical Observations. Riolan, in his Encheiridium, proposed to point out in the structure of the healthy body the seats of the various diseases, and to discuss their nature in conformity with the opinions that had been entertained of them. This was obviously at once a barren and an impracticable route: the matters he had in hand could never have been other than abstractions, and his own observations criticisms on opinions, never on facts. How much more natural and judicious the course which Harvey proposes to himself, when he informs us that in his ‘Medical Anatomy’ he meant, “from the many dissections he had made of the bodies of persons worn out by serious and strange affections, to relate how and in what way the internal organs were changed in their situation, size, structure, figure, consistency, and other sensible qualities, from their natural forms and appearances, such as they are usually described by anatomists; and in what various and remarkable ways they were affected. For even as the dissection of healthy and well-constituted bodies contributes essentially to the advancement of philosophy and sound physiology, so does the inspection of diseased and cachectic subjects powerfully assist philosophical pathology.” This was precisely what Morgagni lived, in some considerable measure, to achieve, and it is that which it has been the business of modern pathology, through the illustrious line of the Baillies, Laennecs, Andrals, Louis, Cruveilhiers, Carswells, Richard Brights, and many others, to render more and more complete.

Riolan never replied to Harvey; but neither did the Parisian Professor attempt to vindicate his views, nor did he exhibit such candour as to own himself otherwise convinced or converted. His doctrine had no abettors, and never bore fruit; it stood a barren ear amidst the lusty, green, and copious harvest, that had already sprung up and overspread the lands.

Harvey must now, indeed, have seen his views assured of general reception at no distant date. The same year in which he himself answered Riolan, Dr. James de Back, of Amsterdam, published his work on the Heart,[41] which is written entirely in harmony with the Harveian doctrines, and the celebrated Lazarus Riverius, Professor of Medicine in the University of Montpellier, publicly defended and taught the circulation of the blood.[42] The following year, Paul Marquard Siegel, of Hamburg, produced his commentary on the Motion of the Blood,[43] in which he addresses himself particularly to a refutation of Riolanus, whose scholar he had been, and at the same time shows himself so thoroughly at home in the general question, that he is able to throw additional light on it by new and ingenious considerations and experiments.

Harvey appears to have been pleased with Slegel’s production; for by and by he sends the Hamburger his new work on Generation, accompanied by an admirable letter, which has happily been preserved.[44] No one in reading that remarkable epistle could suppose that the pen which set it down was in the hand of a man in the 75th year of his age.

The young men of 1628 and 1630, who had been educated in unbelief of the circulation, were now coming into possession of professorial chairs and places of distinction; and having long escaped from leading-strings and made inquiry for themselves, were beginning in many of the European universities to proclaim the better faith through further knowledge that had sprung up within them. Harvey had himself received the seeds of his discovery in Italy; but the fructifying mother was slow to recognize him whom she had so powerfully concurred to form. It was not till 1651 that Harvey’s views were in any way admitted beyond the Alps, when Trullius, a Roman professor, expounded and taught them. About the same time, John Pecquet,[45] of Dieppe, and Thomas Bartholin, the Dane,[46] men of original mind in the one case, of extensive learning and great research in the other, gave in their adhesion to the new doctrine, and spread it far and near by their writings. The victory for the circulation may finally be said to have been won, when Plempius, of Louvain, the old antagonist of Descartes on the subject, retracted all he had formerly written against it, convinced of its truth, as he so candidly informs us, by the very pains, he took to satisfy himself of its erroneousness, and publicly proclaimed his conversion: “Primum mihi hoc inventum non placuit,” says the worthy Plempius—“This discovery did not please me at all at first, as I publicly testified both by word of mouth and in my writings; but by and by, when I gave myself up with firmer purpose to refute and expose it, lo! I refute and expose myself, so convincing, not to say merely persuasive, are the arguments of the author: I examine the whole thing anew and with greater care, and having at length made the dissection of a few live dogs, I find that all his statements are most true.”[47]

From the first promulgation of the doctrine of the circulation, its progress towards ultimate general acknowledgment can scarcely be said for a moment to have been interrupted. The hostility of the Primeroses and Parisanuses and Riolans never interfered with it in fact; the more candid spirits were rather led to inquire, by the virulence of these weak and inconsistent opponents, who thus hastened the catastrophe of their own discomfiture, and the triumph of the truth. If men’s minds were once in danger of being led astray, it was only for an instant, and not so much through the opposition of enemies, as by an erroneous generalization, which a short interval of time sufficed to correct. Cæcilius Folius, a Venetian physician, having met with one of those anomalous instances of pervious foramen ovale in an adult, immediately and without looking farther, jumped to the conclusion that this structure or arrangement was normal, and that the blood passed in all cases by the route he had discovered, from the right to the left side of the heart. Many Italians received with favour the account which Folius immediately published of his discovery;[48] and the natural philosopher, Gassendi, having about the same period had another instance of the kind which Folius encountered, shown to him, concurred with this writer in his views, and by a variety of arguments and objections, strove to damage, and did temporarily damage, the Harveian doctrine.[49] But this was only for a brief season; for Domenic de Marchettis[50] soon after showed that Folius had mistaken an extremely rare occurrence for a general fact, and that if the open foramen ovale might afford a passage from the right to the left side of the heart in one case, closed it would suffer no such transit in hundreds of other instances. Gassendi, moreover, by getting still more out of his depth, soon afterwards showed that familiarity with general physics did not imply a particular knowledge of anatomy, nor give the power of reasoning sagely on subjects of special physiology; so that in his eagerness to assail Harvey he did injury in the end only to his own reputation. In short, Harvey in his lifetime had the high satisfaction of witnessing his discovery generally received, and inculcated as a canon in most of the medical schools of Europe; he is, therefore, one of the few—his friend Thomas Hobbes says, he was the only one within his knowledge—“Solus quod sciam,”[51] who lived to see the new doctrine which he had promulgated victorious over opposition, and established in public opinion. Harvey’s views, then, were admitted; the circulation of the blood, through the action of the heart, was received as an established fact; but envy and detraction now began their miserable work. The fact was so; but it was none of Harvey’s discovering; the fact was so, but it was of no great moment in itself, and the merit of arriving at it was small; the way had been amply prepared for such a conclusion.

Let us look as impartially as we may at each of these statements.

They who deny the originality of Harvey’s induction, very commonly confound the idea of a Motion of the blood, with the idea of a Continuous Motion in a Circle. It would seem that even from remote antiquity, and by common consent, mankind had recognized the blood to be in motion. We have this fact declared to us by all antiquity, and it is even particularly referred to in various passages of the grand observer of his age, the depositary of the popular science of all preceding ages—Shakespeare. Brutus speaks thus to Portia:

“You are my true and honourable wife;
As dear to me as are the ruddy drops
That visit my sad heart;”

language not more touching and beautiful than physiologically correct. And again, with more of involution and ellipsis, yet with a meaning that is unmistakable, Warwick, by the bedside of the murdered Gloster, proceeds,—

“See how the blood is settled in his face!
—Oft have I seen a timely-parted ghost,
Of ashy semblance, meagre, pale and bloodless,
—Being all descended to the labouring heart,
Who in the conflict that he holds with death,
Attracts the same for aidance gainst the enemy;
Which with the heart there cools, and ne’er returneth
To blush and beautify the cheek again—
—But see, his face is black and full of blood,” &c.

These passages have actually been cited, to prove that Shakespeare was not unacquainted with the circulation; and there have not been wanting some[52] who have even argued that Shakespeare had his knowledge direct from the fountain-head—from Harvey himself, with whom, for several years at least, he was contemporaneous.[53]

The passages quoted above are referred to all the more willingly, from their having preceded the teaching of Harvey by a few years only; but Shakespeare probably referred to nothing more than the accredited opinion that the blood was in motion within the vessels, particularly the veins of the body. In ancient times, indeed, the veins were regarded, as they are esteemed by the vulgar at the present hour, as the principal vessels of the body; they only were once believed to contain true blood; the arteries were held to contain at best but a little blood, different from that of the veins, and mixed accidentally in some sort with the vital spirits, of which they were the proper conduits.

In former times, farther,—times anterior to Harvey whether more remotely or more nearly,—the liver, as the organ of the hæmapoësis, was regarded as the source of all the veins, i. e. of all the proper blood-vessels; the heart, as the generator of heat and the vital spirits, was viewed as the mere cistern of the blood, whence it was propelled by the act of inspiration, and whither it reverted during the act of expiration, its flow to this part of the body or to that, being mainly determined by certain excitations there inherent or specially set up. By and by, however, the liver was given up as the origin of the venous system generally; but such anatomists as Jacobus Sylvius, Realdus Columbus, Bartholomæus Eustachius, and Gabriel Fallopius, may be found opposing Vesalius in regard to the origin of the vena cava, and asserting that it takes its rise from the liver, not from the heart, as the great reformer in modern anatomy had maintained.

In the progress of anatomical investigation, the valves in the interior of the heart, at the roots of the two great cardiac arterial trunks, and in the course of the veins at large, were perceived and their probable uses and actions canvassed. The general and prevalent notion was that they served to break or moderate the force of the current in the interior of the vessels or parts where they were encountered; though Berengarius of Carpi,[54] in describing the cardiac valves, had already said that the effect of the tricuspid valves, between the right auricle and ventricle, must be to prevent the blood in the former cavity from escaping into the latter; whilst the office of the semilunar valves, at the origins of the pulmonic artery and aorta, he declared, from their position, must be to prevent the entrance of the blood of the great arterial trunks into the heart. Fabricius, the master of Harvey, may be said to have perfected anatomical knowledge in regard to the valves of the veins—for he by no means first directed attention to their existence, or discovered them, as is generally asserted. Fabricius believed that their function was to act as obstacles to congestions of blood, as strengtheners of the veins and preventives to their becoming over-distended.

Another long and much agitated point in the anatomy of the sanguiferous system, was the state of the septum ventriculorum of the heart, in respect of permeability or impermeability. The reason of the vast importance attached to this point was connected with the ancient, and, in Harvey’s time, generally accredited hypothesis of the Three Spirits—the natural, the vital, and the animal. The hypothesis to be brought into play, was presumed to require the intermixture in the heart of the two kinds of blood that were held appropriate to the two ventricles and to the arteries and veins respectively, and that were farther believed to meet in the cavities of the cranium, thorax, and abdomen, from which they returned to the heart by the way they came, for a fresh supply of the spirits (now exhausted or enfeebled), under the agency of which all the important operations of the body were believed to be accomplished.

Now, Galen, the author of this hypothesis, in order to obtain an admixture of the two kinds of blood, feigned and described the partition between the two ventricles, either as perforated like a sieve, or as filled with depressions of depth sufficient to entitle them to be viewed as constituting a kind of third ventricle—the last assumption doubtless to accommodate each order of spirits with its own particular officine or workshop. With the revival of anatomical knowledge in modern Europe, however, the partition of the ventricles was soon perceived not to be porous or cribriform, but, as was first said, to be so nearly solid that any filtration of blood through it was well nigh impossible (Berengarius, 1521), and next, to be so completely solid that all permeation of blood was impossible (Vesalius, 1555), and another means must therefore be found for securing the necessary admixture of the two kinds of blood in order to effect the engenderment of the natural, animal, and vital spirits.

Such was the state of anatomical science and physiological belief on this particular point when Michael Servetus came upon the stage, and suggested the transit of the blood through the lungs from the right side of the heart to the left, with a view of meeting the difficulty which the undeniable solidity of the septum ventriculorum opposed to the presumed necessary admixture of the two kinds of blood. Servetus’s idea, consequently—if at the distance of three hundred years we may presume to follow the mental process that led to the penning of the remarkable and often-quoted passage which occurs in his works—appears to be nothing more than a suggestion or proposition as a means of meeting a difficulty; it is very much as though he had said: If you cannot go straight through, you must even go round about. To so much and to no more, do Servetus’s claims to be considered a discoverer, in the sense we would attach to that word, amount. The passage from the ‘Restitutio Christianismi’ of Servetus, 1553, if viewed from the point proposed, will not fail to set his title to be regarded as the discoverer of the lesser circulation in its true light—in a light under which it has not yet been seen. We translate so much of the passage as bears on the question under review. “The vital spirit has its origin in the left ventricle, the lungs assisting especially in its generation. It is a subtile spirit * * * It is engendered from the mixture that takes place in the lungs of the inspired air with the elaborated subtile blood which the right ventricle of the heart communicates to the left. But this communication takes place, not by the middle septum of the heart, as is commonly believed, but by a remarkable artifice; the subtile blood of the right side of the heart is agitated in a lengthened course through the lungs, whereby it is elaborated, from which it is thrown of a crimson colour, and from the vena arteriosa (pulmonary artery) is transfused into the arteria venosa (pulmonary veins); it is then mixed in the arteria venosa itself with the inspired air, and by the act of expiration is purified from fuliginous vapours, when, having become the fit recipient of the vital spirit, it is at length attracted by the diastole. Now, that the communication and preparation take place as stated through the lungs, is proclaimed by the various conjunctions and communications of the arterial vein with the venous artery. The remarkable size of the arterial vein (pulmonary artery) confirms this, a vessel which could neither have its actual constitution nor dimensions, nor transmit such a quantity of the purest blood direct from the heart itself, for the mere nourishment of the lungs. Neither would the heart supply the lungs in such proportion, (especially when we see the lungs in the embryo nourished from another source) by reason of those membranes or valves which remain unopened until the hour of birth, as Galen teaches. The blood, consequently, from the moment of birth, is sent, and in such quantity is sent, for another purpose from the heart into the lungs; from the lungs also it is not simple air that is sent to the heart, but air mixed with blood is transmitted through the arteria venosa (pulmonary vein). In the lungs consequently does the mixture take place. The crimson colour is imparted to the spirituous blood by the lungs, not by the heart. There is not room enough in the left ventricle of the heart for so important and so great an admixture; neither is there space there for the elaboration into the crimson colour. Finally, the septum medium, seeing that it is without vessels and properties, is not adapted to accomplish that communication and elaboration, although something may transude through it.”

The discussion in this passage from Servetus obviously concerns the generation of the vital spirit, not the pulmonic circulation properly so called—that is altogether secondary and subordinate. His mention of “numerous communications between the vena arteriosa and the arteria venosa,” is plainly conjectural; neither he, nor any one else for a century after him, saw such communications. The course through the lungs, then, as suggested by Servetus, was a mere hypothetical proposal for getting over the difficulty of the solid, or nearly solid, septum ventriculorum. As to the means by which such a transfusion as he suggests, is effected, Servetus, as he was profoundly ignorant himself, so does he leave his readers entirely in the dark. The transmission of the blood from the right to the left side of the heart, which Servetus proposed, is in fact, no great improvement on the old efflux and reflux, like the tides of Euripus, betwixt Attica and Eubœa. He had no conception of a circle of the blood beginning and ending in the heart. On the contrary, he regarded the liver as the fountain-head of the blood; and if he has any reference to a moving power in connexion with the heart, it is nothing more than the diastole or dilatation of the organ that is named—a passive state therefore considered as an active and efficient cause, which is absurd.

The first modern anatomist of high repute, who treats particularly of the motion of the blood, may be said to be Realdus Columbus;[55] for Servetus, though educated to the medical profession, had long forsaken it for divinity, and only uses his old anatomical knowledge as a means of illustrating a theological dogma. Columbus, in treating of the heart and lungs, has certainly much that is remarkable, and much that is true; and had he said nothing more than we find in single detached sentences or paragraphs of his book, he must have been regarded as having gone a great length in the right direction. The blood, he says, once it has entered the right ventricle from the vena cava, can in no way again get back; for the tricuspid valves are so placed that whilst they give a ready passage to the stream inwards, they effectually oppose its return. The blood continuing to advance from the right ventricle into the vena arteriosa or pulmonary artery, once there cannot flow back upon the ventricle, for it is opposed by the sigmoid valves situate at the root of the vessel. The blood, therefore, agitated and mixed with the air in the lungs, and having thus in some sort acquired the nature of spirit, is carried by the arteria venosa or pulmonary vein into the left ventricle, from whence, being received into the aorta, it is, by the ramifications of this vessel, transmitted to all parts of the body.

This much taken by itself looks very like an exposition of the circulation of the blood as understood at the present time, though we still see that the blood must be made to participate in the nature of spirit before it enters the arteries, and is not the blood which is contained in the veins, and which nourishes the body; but when we go farther and turn to other parts of his writings, we see that Columbus could never have conceived any proper idea of the circulation. For example, he continues, with Galen, to regard the liver as the origin of all the veins. The vena portæ, he says, arising by innumerable roots from the concavity of the liver, proceeds to carry blood from this organ by different branches to the stomach, spleen, and intestines, to the end that it may convey nourishment in the first case, black bile in the second, and in the third serve a double function—viz. supply nourishment to the intestines at once, and by a kind of imbibition, obtain nutritive matter, which is forthwith sent back to the liver for elaboration into blood. The vena cava again, he describes as arising from the convex aspect of the liver, whence, by its ramifications, it carries the blood that is requisite to nourish and maintain every part of the body.

This of itself is enough. But when, in addition, we find that Columbus denies the muscular nature of the heart, we are fully qualified to form a true estimate of the conception which he could have had of the motion of the blood, and of his right to be regarded as the discoverer of its ceaseless circular movement.

The next who is brought upon the scene with the imputed honour of having had a knowledge, not only of the lesser, but of the greater or systemic circulation also, is Andreas Cæsalpinus,[56] of Arezzo. The account which this celebrated peripatetic philosopher gives of the passage of the blood from the right to the left side of the heart is essentially the same as that given by Columbus. From the right ventricle the blood passes into the pulmonic artery, and from this, by numerous anastomoses, into the pulmonic veins, which transmit it to the left ventricle. Cæsalpinus says well that it is absurd to call the pulmonary artery by the name of vena arteriosa, on the mere ground of its taking its departure, like the vena cava, from the right ventricle; it is a true artery, and is, in all respects, analogous to the aorta. The title of arteria venosa, again, given to the pulmonic vein is not less ridiculous; inasmuch as this vessel, though it end in the left ventricle, has all the properties of the veins at large.

So far it looks as if Cæsalpinus had an exact idea of the pulmonary circulation; indeed, he uses the word Circulation in reference to the transit of the blood through the lungs; but when we discover him still speaking of the permeation of the septum ventriculorum by the blood, our faith in the extent and accuracy of his knowledge begins to waver.

With reference to the greater or systemic circulation, again, Cæsalpinus speaks of the swelling of the veins between the circle of pressure and the extremities of the vessels, when a ligature is thrown round a limb; and he even goes so far as to state that the common opinion which admitted a progressive motion—i. e. a motion from trunks to branches—of the blood in the veins was erroneous. Did we go no farther we should be led to conclude, as in Columbus’s case, that Cæsalpinus believed in the continuous movement of the blood in the veins in one direction only; and, as he has already spoken of the exit of the blood from the left ventricle, and of its reception by the aorta for general distribution, it might forthwith be inferred that, possessed of the essential elements of the greater circulation, he must, as matter of course, have been familiar with this as an ultimate result. And such an inference has indeed been drawn for him by high authority; but Cæsalpinus came not himself to any such conclusion; it was arrived at by others in his behalf, and after the lapse of almost a century from the date of his first publication. When we find Cæsalpinus, in other and closely connected passages of his writings, singing the old cuckoo note about a flux and reflux of the blood in the veins, and even using the accredited word—Euripus—to express his idea of its tide-like nature; when we further perceive that he was ignorant of the existence of the valves of the veins, and finally arrive at his explanation of the cause of the swelling which takes place in the veins of an extremity beyond a ligature,—the cause with him consisting in an effort of the blood to get back to the focus or centre, lest, through the compression of the veins, it should be cut off and suffocated,—we not only feel that we were warranted in entertaining a wholesome scepticism of the conclusion come to by the admirers of Cæsalpinus in regard to his knowledge of a circulation of the blood; but waxing in our infidelity as we become farther acquainted with his thoughts on the constitution of the blood, we find everything opposed to the likelihood of his having arrived at the same result as Harvey; and, at length, we discover that he neither had nor could have had any true knowledge of the circulation. Starting from the Aristotelian doctrines of growth and nutrition (of which so much will be found in Harvey’s work on Generation), Cæsalpinus held that there were two kinds of blood, one for the growth, another for the nourishment of the body. The blood which went to augment the body, and which he designated alimentum auctivum, or aliment of increase, flowed from the liver into the vena cava, which he seems to have thought was connected with the heart only, ut inde virtus omnis a corde descendat—that a sufficiency of virtue might be thereby communicated to it. The auctive blood, he farther thought, was attracted into the ventricles of the heart by the inherent heat of the organ. The dilatation of the heart and arteries he imagined to be due to “an effervescence of the spirit;” and the cause of their “collapse”—not systole, be it observed, in the active sense—was the appropriation by the parts of the body of the nutritive and augmentative matter. Again, though Cæsalpinus speaks of the intercommunication of the minute arteries and veins, he still thought that it was only during sleep that the blood mixed with the spirits passed from the former into the latter class of vessels; for it is during sleep, he says, that the veins become distended, whilst the pulsations of the arteries are then moderated. He plainly sees no connexion between a delivery by the artery and a filling by the vein. It is along with all this, and as if to settle the question of the kind of knowledge Cæsalpinus had of the movement of the blood, that he uses the old word Euripus, to express his idea of its alternating or tide-like motion.

Cæsalpinus, let us add, had no conception of the heart as the efficient cause of any motion which the blood might have. In the often-quoted passage from the work ‘De Plantis,’[57] it is still the spirit inherent in, or associated with, the blood, that is the cause of its motion.

Cæsalpinus, consequently, tried by a very moderately searching criticism, presents himself to us as but very little farther advanced than the ancients in his ideas on the motion of the blood.—The interpretation which successive generations of men give to a passage in a writer, some century or two old, is very apt to be in consonance with the state of knowledge at the time, in harmony with the prevailing ideas of the day, and, doubtless, often differs signally from the meaning that was in the mind of the man who composed it. The world saw nothing of the circulation of the blood in Servetus, Columbus, Cæsalpinus, or—Shakespeare, until after William Harvey had taught and written.

The truth is, that some of the foremost grounds of Harvey’s claims to rank as a discoverer are very commonly overlooked. We always associate his name and fame with the development of the ultimate fact of the circulation of the blood. But Harvey, as a step to this conclusion, first demonstrated the heart as the means by which the circulation was effected; and he farther showed that there was but one kind of blood, common to both the arteries and the veins. Up to his time the heart was regarded as the passive cistern of the blood, and the elaboratory of the vital spirits; it was not known as the moving instrument in any efflux or reflux of the blood, or even of any lesser circulation that had been previously asserted or conjectured. The moving power was still the respiratory act. Harvey may be said to have first broached, as he also essentially completed the physiology of the heart’s actions. The circular motion of the blood followed as a necessary corollary from these. The “motion of the heart” has even precedence in the title of his immortal work; the chapter in which he first enters properly on his subject (Chap. 2), is devoted to its consideration. And then, no physiologist up to Harvey’s time had questioned the existence of two kinds of blood, one appropriate to each order of vessels, and answering different ends in the economy.

The only name still wanting in this historical sketch, till we come to Harvey, is that of Fabricius of Aquapendente, his teacher in anatomy. Fabricius had given particular attention, among other subjects, to the anatomy of the valves of the veins, which he entitled ostila venarum. Fabricius, indeed, possessed so thorough a knowledge of the valvular elements of the vascular system, that it is really astonishing, as an able writer[58] has remarked, that he should not have had clearer ideas on the functions, among other things, of the pulmonary veins, and should have continued a rigid adherent to the prejudices which prevailed before his time. Fabricius could observe, and he could describe; but he wanted the combining intellect that infers, the imagination that leads to new ideas—to discovery. Though he did little himself, however, to advance the sum of human knowledge, he proved a tooth in the wheel that has since put in motion the whole machinery of modern medical science. He it was who sowed the seed, little dreaming of its kind, which, finding one spot of congenial soil, sprung up a harvest that has continued to nurture the world of physiological science to the present hour.[59]

Having now disposed of the claims that have been set up in behalf of one or another as the discoverer of the circulation, and shown, we trust satisfactorily, that these are all alike untenable, we should now proceed to discuss the question of the cui bono?—but this meets us in so forbidding an aspect, brimful as is our mind with a sense of the all-importance of the knowledge we had from Harvey, and seems so little to belong to our subject, that we gladly pass it by unnoticed; though it be only to find ourselves encountered by that other topic, but little more congenial to our mood of mind and intimate persuasion: The merit of Harvey as a discoverer. Few, very few have been found to question this; but as one man of undeniable learning and eminence in his profession,[60] has very strangely, as it seems to us, been led to do so, it will not be impertinent if we cast away a few words on this matter.

Discovery is of several, particularly of two kinds: one sensible or perceptive; another rational or inductive; the former an act of simple consciousness through an impression made on one or more of the senses; the latter a conclusion come to by the higher powers of the understanding dealing with data previously acquired by the senses and perceptive faculties.—We look through a telescope, for example, and we perceive a star which no one else had seen before; we note the fact, and so become discoverers of a new star. The merit here is not, surely, very great, though the added fact may be highly important. Again, one of the planets is subject to such perturbations in its course that to compose exact tables of its orbit is held impossible. These perturbations are referable to none of the known perturbing causes. A great astronomer suggests the influence of an exterior and unknown planet as their cause. A consummate mathematician and physical astronomer makes trial of this suggestion: he assumes the ascertained perturbations as elements, he combines these under the guidance of knowledge and reason, and at length he says, if the cause suggested be well founded, there or thereabouts must it exist; and lo! on turning the far-seeing tube to the point in space which he had indicated, there in verity gleams a new world, then first seen, though launched by God from Eternity to circle on the verge of our creation; and he who bade us look becomes the discoverer of a new planet. Who will dispute the merit here? Truly, man does show the God within him when he uses his faculties—God-like in themselves—in such God-like fashion. But Harvey’s merit, according to our idea, was of the selfsame description in another sphere. The facts he used were familiarly known, most of them to his predecessors for nearly a century, all of them to his teachers and immediate contemporaries; yet did no one, mastering these facts in their connexion and sequence, rising superior to prejudice, groundless hypothesis, and erroneous reasoning, draw the inference that now meets the world as irresistible, until the combining mind of Harvey gave it shape and utterance. To our apprehension Harvey was as far above his fellows as the eye of poetic intelligence, that exultingly absorbs the beauties of the starry sky and the green earth, is above the mere physical sense that distinguishes light from dark. The late Dr. Barclay, a fervent admirer of Harvey, whose name he never uttered without the epithet immortal, has put the question of Harvey’s merit both happily and eloquently, and it affords us pleasure to quote the passage from the writings of our old and honoured teacher in anatomy. “The late Dr. Hunter,” says Dr. Barclay,[61] “has rather invidiously introduced Harvey along with Copernicus and Columbus, to show that his merit as a discoverer was comparatively low. But what did Copernicus, and what did Columbus? Not in possession of more numerous facts than their contemporaries, but endowed with nobler and more vigorous intellects, the one developed the intricate system of the heavenly bodies and the other discovered an unheard-of continent. Was it not in the same way, by the exertion of superior intellect, that Harvey made his immortal discovery? I know not what has happened in the world unseen; but if I may judge from the records of history and the annals of fame, the spirit of Bacon, the spirits of Columbus, Copernicus and Newton have not been ashamed to welcome and associate with the congenial spirit of Harvey.” To this fine passage there is little to be added: Harvey’s discovery was of the rational and inductive and therefore higher class, according to our estimate; it was made in virtue of the intellectual powers which peculiarly distinguish man, possessed in a state of the highest perfection.