Imatges de pÓgina

before the mind in quick succession the awful realities of sickness, death, and a coming eternity; and which is, at the same time, second to one only, in the opportunities it affords to fulfil the apostolic maxim-" Let us do good unto all men, especially unto them who are of the household of faith."


"THE wisdom of the Creator," it has been well said, "is in nothing seen more gloriously than in the heart and blood-vessels:"-the action of the latter is essential to the performance of every function, and diffusing life, health, and vigour, through the entire animal frame; the cessation of the former, for a short period, absolutely fatal; the whole, nevertheless, so constructed as to go on at the rate of a hundred thousand pulsations in every twenty-four hours, for a period of from seventy to eighty years without disorder, without interruption, and without weariness! And yet so simple is the contrivance by which all this is brought about, that the next thing which astonishes us is the fact, that so many years elapsed before it was at all accurately understood. The arteries were found empty after death; it was, therefore, concluded that they merely conveyed air or some kind of "animal spirits." The veins alone were supposed to

convey blood. By some it was propounded that the fluids moved along the vessels in one direction during the day, and in the contrary direction during the hours of sleep, with many other equally chimerical and unfounded hypotheses. In the sixteenth century, a little more light was thrown upon the subject. By the researches of Servetus and of the Italian anatomists, Colombo and Cesalpini, the lesser circulation through the lungs, the fact of the blood being acted upon by the air, the existence of valves in the veins, and a few other particulars, were made out. But it was reserved for our illustrious countryman, in the century before last, to connect the whole into one harmonious system; to announce to the world the great discovery of the true doctrine of the circulation of the blood; to open up a new era in medical science; and to introduce as great a revolution in the sciences of anatomy and physiology, as Newton afterwards did in those of astronomy and optics, by his theories of gravitation and light.

WILLIAM HARVEY was descended from a respectable family in Kent, and was born at Folkestone on the 1st of April, 1578. His education was conducted first at a grammar school in Canterbury, and afterwards at Gonville and Caius College at Cambridge. To minds of a certain order, some comparatively trivial event, carefully pondered, not unfrequently opens the path to dis

coveries of the greatest magnitude. There seems, at first sight, little relation between the fall of an apple, and the splendid scientific achievements of Newton. Yet it was a train of thought, directed by this apparently trifling circumstance, which conducted him to the whole of them. Thus it was with Harvey. In the course of his travels, for the completion of his medical education, he settled for a short time at Padua. Fabricius ab Aquapendente was then at the height of his reputation as a professor of anatomy in the university of that place. The theatre, built at his expense, is still exhibited to visitors at Padua. Its circular seats, rising almost perpendicularly one above another, now nearly black with age, give to the small apartment, which is wainscoted with curiously carved oak, a solemn and venerable appearance. The lectures were given by candlelight, as, from the construction of the theatre, no other light could be admitted. Here it was that Harvey caught the first glimpse of the discovery which has since immortalized his name. Fabricius one day pointed out the existence of valves in the veins-not, however, that he had the slightest conception of their use, for the only conjecture that he could hazard was, that they might be designed to moderate the flow of blood from the trunks of the veins to their smaller branches, taking it for granted that such was the course of the circulation. This was enough for his intelligent pupil. There were valves

in the veins undoubtedly; but could this be the intention of them? He would not place implicit dependence upon any teacher, however celebrated, but would examine for himself. Valves opening towards the heart seemed calculated to impede altogether, rather than to retard merely, the flow of blood in a direction from that organ. Tie up a vein or compress it, as is done in the simple operation of bleeding, and that portion of the vessel which is at the greatest distance from the heart will swell and become distended. Whereas, he soon discovered that, if an artery were tied, just the contrary happened; that part became enlarged which was nearest to the heart. Hence he was led by various experiments, step by step, till he clearly demonstrated that the heart is first of all excited to contract by the stimulus of the blood, that this fluid is impelled through the arteries, and, after having served every purpose of secretion and nourishment, returns by the veins to recommence the circulation.

Great, however, as the discovery undoubtedly was-immense as was its practical advantage-simple and easily demonstrable as it now appears, Harvey durst not for many years even drop a hint upon the subject in his comparatively private lectures, and it was not until nearly thirty years had elapsed that he ventured to publish to the world, not in his own country, but at Frankfort, the results of his experiments. And then nothing could

exceed the contempt and ridicule with which it was received. Had he lived in a country unblessed with the light of the Reformation, he would probably have shared the fate of Galileo. As it was, he was accused of propagating doctrines tending to subvert the authority of Holy Scripture, the epithet circulator, in its Latin invidious signification, (quack,) was applied to him, it was given out that he was "crack-brained," and his practice as a physician sensibly declined. In a quarter of a century more, his system was received in all the universities of the world, and Harvey lived to enjoy the reputation he so justly merited.

The date of the first promulgation of his then novel views has not been accurately ascertained. Thus much is certain,-Harvey graduated at Padua and afterwards at Cambridge in the year 1602, soon after which he settled in the practice of his profession in London. In 1607, he was elected Fellow of the College of Physicians, and in 1615, he was appointed reader of the anatomical and surgical lectures founded by lord Lumley and Dr. Caldwell. In the British Museum, there is an original MS. of his lectures of the date of April, 1616, which contains the propositions on which his doctrine is founded. it was not till 1628, when he was in his fiftieth year, that he published the great work already referred to. Some curious preparations, rude enough, but, under the circumstances of the


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