William Harvey.

BORN A. D. 1578.-died a. D. 1657.

THIS celebrated anatomist was born on the first of April 1578, at Folkeston in Kent. He was the eldest of seven children, the second of whom, Eliab, afterwards became a great Turkey merchant and amassed a considerable fortune. He was educated at the grammar school in Canterbury. At the age of 15 he went to the university of Cambridge, where he was admitted a pensioner of Gonville and Caius college. The situation of pensioner is described by his biographer, Dr Laurence, to be one in which the individual is not supported on the foundation but pays his own expenses; the word being used in a sense directly opposite to the ordinary one. After six years spent in Cambridge in the study of the philosophy of the day, he went abroad for the purpose of acquiring medical information, the university of Padua being then in high reputation. The anatomical chair was then filled by the celebrated Fabricius ab Aquapendente, of whom Harvey became an attentive follower. The chair of medicine was filled at the same time by Minadous, and that of surgery by Casserius. In this university he took the degree of doctor in medicine in the year 1602; on his diploma are the signatures of the celebrated professors above mentioned, fac similes of which will be found in the London edition of his works, published in 1766.

As usual with physicians of his day, he graduated a second time in the university of Cambridge, on his return to England in 1602. He commenced practice in London as one of the candidati of the college of physicians, of which he was elected a fellow three years afterwards. He was now appointed successor to Dr Wilkinson as physician to St. Bartholomew's hospital; and this gentleman dying the year after, he entered on the duties of his office. In 1604, he married the daughter of Dr Lancelot Browne, but had no children. At the age of thirtyseven he was appointed lecturer on anatomy and surgery to the college of physicians; and in the course of the lectures delivered there, he first explained his views respecting the circulation of the blood. The manuscript copy of these lectures fell into the possession of Sir Hans Sloane, and afterwards, along with the rest of his valuable collection, became the property of the British museum in which they are now to be found. Some years ago a set of relics of equal value was presented to the college of physicians by the earl of Winchelsea, a descendant of the brother of Harvey. They consist of six tables or boards on which the blood-vessels and arteries of the body are spread out and dried; which, it is probable, were made by Harvey himself, and employed for the purpose of demonstration, in the course of his anatomical lectures. He was chosen lecturer in 1615, and it is believed that he first mentioned his discovery in 1619, though his manuscript De Anatomia Universa,' refers the date of his acquaintance with it to 1616. In order that we may appreciate properly the views introduced into anatomy by Harvey, it will be necessary that we take a glance at the ideas respecting the circulation of the blood which prevailed previous to his time.

The works of Galen and others, show that in ancient times there was

not the slightest suspicion of the true nature of the circulation. The blood was supposed to be formed in the liver,-to flow backwards and forwards in the veins,-to pass partly into the left side of the heart, where the air inhaled by the lungs was supposed to mingle with it and form a vital spirit, which, in the same way as the blood in the veins, was said to form a flux and reflux in the arteries. The first grand step towards the cruth was made by Michael Servetus, who was born at Villa Nueva, in Arragon, in the year 1509. He discovered that the idea of the blood passing directly from the right to the left cavity of the heart was erroneous, and showed that it circulated in the vessels of the lungs. He was of opinion that in its passage through the lungs, the blood becomes vitalized and fitted for the formation of vital spirit, which was still supposed to be completed in the left ventricle of the heart. This discovery appears to have been scarcely noticed by anatomists; for several years afterwards, Columbus, professor of anatomy at Padua, announced the same as his own, having been ignorant of the views of Servetus. Perhaps this arose from the title of the work in which Servetus explained his notions; it was a treatise on the Trinity. Not long after this time, doubts were thrown upon the accuracy of the ancient notion by the observations of Carsalpinus, an Italian physician. He remarked that when pressure was applied to a vein, an accumulation of blood takes place on the side most distant from the heart, a circumstance entirely opposed to the theory of the day; for, as he says, "debuisset opposito modo contingere." He properly remarked also that the existence of valves at the origin of the arterial system was not consistent with the common idea of flux and reflux of the vital spirit. With all this information, however, the grand notion of a general circulation was not suggested to him. Fabricius ab Aquapendente, under whom Harvey studied, advanced a step farther, by establishing the doctrine of the existence of valves in the veins, which though supported by Jacobus Sylvius and Vesalius, had been almost suppressed by the opposition of Eustachius and Fallopius. "It was this discovery," says Dr Baillie in one of his introductory lectures, "which probably first led Harvey to reflect on the course of the fluid in the arteries and veins, an inference which now appears sufficiently obvious; but it might long have remained concealed, if it had not met with an observing mind, which readily caught it, and thus unfolded the most important general action in an animal body." A very few words will suffice to explain the doctrine of Harvey and the principles on which he founded it. The contractions of the heart being known, it was evident that the blood must be sent into the vessels communicating with its cavities. It was found that at the origin of these vessels there were valves which effectually prevented the same fluid from directly returning to the heart; its motion must therefore either be at a stand, or it must pass onwards in the vessels, being impelled by a new quantity forced onwards by the renewed action of the heart. This is the case in the aorta and arterial system, which arise from the left ventricle of the heart, and in the pulmonary artery which receives the blood propelled by the action of the right ventricle. It became now a question what course the blood follows, since the valves prevent its return to the heart by the same passage through which it is expelled. That which is sent into the lungs by the right ventricle, was already known to re

turn to the heart by the pulmonary vein, which discharges its contents into the left side of that organ; but the future course of the blood was not known. It is forced into the arterial system, but it was never suspected that it continued its course through the ramifications of that system and returned to the heart through the veins. This was the discovery of Harvey. As the blood is propelled through the arteries by the contractions of the heart, and is found to flow in an opposite direction in the veins; and as the valves of these vessels permit of motion of the fluid only in one direction, it follows that the blood circulates through the body in general in the same way as through the lungs. The principles of the modern doctrine of the circulation are therefore the following:-The heart is the centre, consisting in man of two essential parts; from the one (the right side) the blood is driven through the lungs to be purified; returning from these into the left side, from which it is distributed through the system by the arteries; having supplied the wants of the body, it returns through the veins to the right side of the heart, to be again purified by a circulation through the lungs, and fitted for re-entering the arteries. We need not here enter more minutely into a description of the apparatus of the circulation, nor into the additions which the discovery of Harvey has received from the labours of more modern physiologists.

Though there can be no doubt that Harvey had formed clear notions on this important subject so early as the year 1616, he nevertheless wisely abstained from bringing them before the world till he had by mature consideration and careful experiment convinced himself that he had avoided every source of error. It was not, therefore, till the year 1628, that he committed to the press his work on the motion of the heart and blood, which appeared, with a dedication to Charles the First, at Francfort on the Maine. The appearance of this work was the signal for the commencement of a series of attacks similar to those which almost every author of an important discovery has had to suffer. Some anatomists attempted to subvert his reasoning; others to prove that it was known before, and to give to others the honour of the original discovery. His biographer Dr Laurence says, "Sed nemo vir magnus unquam fuit, quem nulla acqualium pressit invidia." The first effect which the publication of his system produced was a decline in his practice-a circumstance which we cannot easily account for. One of his biographers says, that "he ascribed it to the opposition and jealousy of his rivals; but it is more likely, that the habits of abstract speculation, in which he now began to indulge, caused him to neglect the usual arts of gaining the confidence of the public, which if a physician ever possess, he needs not the confidence, and may boldly set at defiance the envy of his professional brethren." The first public attack made on his system was that of Primirosius, a scholar of Riolan, who "ingenii scilicet exercendi causâ," supported with much ingenuity the theory of Galen. To a work written in this spirit, "and to weapons thrown by a beardless enemy, such as Primirosius," Harvey did not condescend a reply. The next opponent was Parisanus, a physician of Venice; described by Laurence as "homo verborum longis ambagibus et loquacitate copiosa odiosus, sententiis in sententias interjectis, of rerum ordine perturbato obscurus, sermone barbarus et lutulentus." This was a feeble enemy, for he fought not by the power of reason, but