In every section, Vesalius enlarged and corrected the work of Galen. Into the details we need not enter: they are all given in Roth's monograph, and it is a chapter of ancient history not specially illuminating.

Never did a great piece of literary work have a better setting. Vesalius must have had a keen appreciation of the artistic side of the art of printing, and he must also have realized the fact that the masters of the art had by this time moved north of the Alps.

While superintending the printing of the precious work in the winter of 1542-1543 in Basel, Vesalius prepared for the medical school a skeleton from the body of an executed man, which is probably the earliest preparation of the kind in Europe. How little anatomy had been studied at the period may be judged from that fact that there had been no dissection at Basel since 1531.(22) The specimen is now in the Vesalianum, Basel, of which I show you a picture taken by Dr. Harvey Cushing. From the typographical standpoint no more superb volume on anatomy has been issued from any press, except indeed the second edition, issued in 1555. The paper is, as Vesalius directed, strong and good, but it is not, as he asked, always of equal thickness; as a rule it is thick and heavy, but there are copies on a good paper of a much lighter quality. The illustrations drawn by his friend and fellow countryman, van Calcar, are very much in advance of anything previously seen, except those of Leonardo. The title-page, one of the most celebrated pictures in the history of medicine, shows Vesalius in a large amphitheatre (an imaginary one of the artist, I am afraid) dissecting a female subject. He is demonstrating the abdomen to a group of students about the table, but standing in the auditorium are elderly citizens and even women. One student is reading from an open book. There is a monkey on one side of the picture and a dog on the other. Above the picture on a shield are the three weasels, the arms of Vesal. The reproduction which I show you here is from the "Epitome"—a smaller work issued before (?) the "Fabrica," with rather larger plates, two of which represent nude human bodies and are not reproduced in the great work. The freshest and most beautiful copy is the one on vellum which formerly belonged to Dr. Mead, now in the British Museum, and from it this picture was taken. One of the most interesting features of the book are the full-page illustrations of the anatomy of the arteries, veins and nerves. They had not in those days the art of making corrosion preparations, but they could in some way dissect to their finest ramifications the arteries, veins and nerves, which were then spread on boards and dried. Several such preparations are now at the College of Physicians in London, brought from Padua by Harvey. The plates of the muscles are remarkably good, more correct, though not better perhaps, on the whole, than some of Leonardo's.

(22) The next, in 1559, is recorded by Plater in his autobiography, who gave a public dissection during three days in the Church of St. Elizabeth.

Vesalius had no idea of a general circulation. Though he had escaped from the domination of the great Pergamenian in anatomy, he was still his follower in physiology. The two figures annexed, taken from one of the two existing copies of the "Tabulae Anatomica," are unique in anatomical illustration, and are of special value as illustrating the notion of the vascular system that prevailed until Harvey's day. I have already called your attention to Galen's view of the two separate systems, one containing the coarse, venous blood for the general nutrition of the body, the other the arterial, full of a thinner, warmer blood with which were distributed the vital spirits and the vital heat. The veins had their origin in the liver; the superior vena cava communicated with the right heart, and, as Galen taught, some blood was distributed to the lungs; but the two systems were closed, though Galen believed there was a communication at the periphery between the arteries and veins. Vesalius accepted Galen's view that there is some communication between the venous and arterial systems through pores in the septum of the ventricles, though he had his doubts, and in the second edition of his book (1555) says that inspite of the authority of the Prince of Physicians he cannot see how the smallest quantity of blood could be transmitted through so dense a muscular septum. Two years before this (1553),(*) his old fellow student, Michael Servetus, had in his "Christianismi Restitutio" annatomical touch with one another!

(*) See the Servetus Notes in the Osler Anniversary Volumes, New York, 1919, Vol. II.—Ed.

The publication of the "Fabrica" shook the medical world to its foundations. Galen ruled supreme in the schools: to doubt him in the least particular roused the same kind of feeling as did doubts on the verbal inspiration of the Scriptures fifty years ago! His old teachers in Paris were up in arms: Sylvius, nostrae aetatis medicorum decus, as Vesalius calls him, wrote furious letters, and later spoke of him as a madman (vaesanus). The younger men were with him and he had many friends, but he had aroused a roaring tide of detraction against which he protested a few years later in his work on the "China-root," which is full of details about the "Fabrica." In a fit of temper he threw his notes on Galen and other MSS. in the fire. No sadder page exists in medical writings than the one in which Vesalius tells of the burning of his books and MSS. It is here reproduced and translated.(23) His life for a couple of years is not easy to follow, but we know that in 1546 he took service with Charles V as his body physician, and the greatest anatomist of his age was lost in the wanderings of court and campaigns. He became an active practitioner, a distinguished surgeon, much consulted by his colleagues, and there are references to many of his cases, the most important of which are to internal aneurysms, which he was one of the first to recognize. In 1555 he brought out the second edition of the "Fabrica," an even more sumptuous volume than the first.

(23) Epistle on China-root, 1546, p. 196. Vesalius may be quoted in explanation—in palliation:

"All these impediments I made light of; for I was too young to seek gain by my art, and I was sustained by my eager desire to learn and to promote the studies in which I shared. I say nothing of my diligence in anatomizing—those who attended my lectures in Italy know how I spent three whole weeks over a single public dissection. But consider that in one year I once taught in three different universities. If I had put off the task of writing till this time; if I were now just beginning to digest my materials; students would not have had the use of my anatomical labours, which posterity may or may not judge superior to the rechauffes formerly in use, whether of Mesua, of Gatinaria, of some Stephanus or other on the differences, causes and symptoms of diseases, or, lastly, of a part of Servitor's pharmacopoeia. As to my notes, which had grown into a huge volume, they were all destroyed by me; and on the same day there similarly perished the whole of my paraphrase on the ten books of Rhazes to King Almansor, which had been composed by me with far more care than the one which is prefaced to the ninth book. With these also went the books of some author or other on the formulae and preparation of medicines, to which I had added much matter of my own which I judged to be not without utility; and the same fate overtook all the books of Galen which I had used in learning anatomy, and which I had liberally disfigured in the usual fashion. I was on the point of leaving Italy and going to Court; those physicians you know of had made to the Emperor and to the nobles a most unfavourable report of my books and of all that is published nowadays for the promotion of study; I therefore burnt all these works that I have mentioned, thinking at the same time that it would be an easy matter to abstain from writing for the future. I must show that I have since repented more than once of my impatience, and regretted that I did not take the advice of the friends who were then with me."

There is no such pathetic tragedy in the history of our profession. Before the age of thirty Vesalius had effected a revolution in anatomy; he became the valued physician of the greatest court of Europe; but call no man happy till he is dead! A mystery surrounds his last days. The story is that he had obtained permission to perform a post-mortem examination on the body of a young Spanish nobleman, whom he had attended. When the body was opened, the spectators to their horror saw the heart beating, and there were signs of life! Accused, so it is said, by the Inquisition of murder and also of general impiety he only escaped through the intervention of the King, with the condition that he make a pilgrimage to the Holy Land. In carrying this out in 1564 he was wrecked on the island of Zante, where he died of a fever or of exhaustion, in the fiftieth year of his age.

To the North American Review, November, 1902, Edith Wharton contributed a poem on "Vesalius in Zante," in which she pictures his life, so full of accomplishment, so full of regrets—regrets accentuated by the receipt of an anatomical treatise by Fallopius, the successor to the chair in Padua! She makes him say:

There are two ways of spreading light; to be The candle or the mirror that reflects it. I let my wick burn out—there yet remains To spread an answering surface to the flame That others kindle.

But between Mundinus and Vesalius, anatomy had been studied by a group of men to whom I must, in passing, pay a tribute. The great artists Raphael, Michael Angelo and Albrecht Durer were keen students of the human form. There is an anatomical sketch by Michael Angelo in the Ashmolean Museum, Oxford, which I here reproduce.(*) Durer's famous work on "Human Proportion," published in 1528, contains excellent figures, but no sketches of dissections. But greater than any of these, and antedating them, is Leonardo da Vinci, the one universal genius in whom the new spirit was incarnate—the Moses who alone among his contemporaries saw the promised land. How far Leonardo was indebted to his friend and fellow student, della Torre, at Pavia we do not know, nor does it matter in face of the indubitable fact that in the many anatomical sketches from his hand we have the first accurate representation of the structure of the body. Glance at the three figures of the spine which I have had photographed side by side, one from Leonardo, one from Vesalius and the other from Vandyke Carter, who did the drawings in Gray's "Anatomy" (1st ed., 1856). They are all of the same type, scientific, anatomical drawings, and that of Leonardo was done fifty years before Vesalius! Compare, too, this figure of the bones of the foot with a similar one from Vesalius.(24) Insatiate in experiment, intellectually as greedy as Aristotle, painter, poet, sculptor, engineer, architect, mathematician, chemist, botanist, aeronaut, musician and withal a dreamer and mystic, full accomplishment in any one department was not for him! A passionate desire for a mastery of nature's secrets made him a fierce thing, replete with too much rage! But for us a record remains—Leonardo was the first of modern anatomists, and fifty years later, into the breach he made, Vesalius entered.(25)

(*) This plate was lacking among the author's illustrations, but the Keeper of the Ashmolean Museum remembers his repeatedly showing special interest in the sketch reproduced in John Addington Symonds's Life of Michelangelo, London, 1893, Vol. I, p. 44, and in Charles Singer's Studies in the History and Method of Science, Oxford, 1917, Vol. I, p. 97, representing Michael Angelo and a friend dissecting the body of a man, by the light of a candle fixed in the body itself.—Ed.

(24) He was the first to make and represent anatomical cross sections. See Leonardo: Quaderni d'Anatomia, Jacob Dybwad, Kristiania, 1911-1916, Vol. V.

(25) See Knox: Great Artists and Great Anatomists, London, 1862, and Mathias Duval in Les Manuserits de Leonard de Vince: De l'Anatomie, Feuillets A, Edouard Rouveyre, Paris, 1898. For a good account of Leonardo da Vinci see Merejkovsky's novel, The Forerunner, London, 1902, also New York, Putnam.



HARVEY

LET us return to Padua about the year 1600. Vesalius, who made the school the most famous anatomical centre in Europe, was succeeded by Fallopius, one of the best-known names in anatomy, at whose death an unsuccessful attempt was made to get Vesalius back. He was succeeded in 1565 by a remarkable man, Fabricius (who usually bears the added name of Aquapendente, from the town of his birth), a worthy follower of Vesalius. In 1594, in the thirtieth year of his professoriate, he built at his own expense a new anatomical amphitheatre, which still exists in the university buildings. It is a small, high-pitched room with six standing-rows for auditors rising abruptly one above the other. The arena is not much more than large enough for the dissecting table which, by a lift, could be brought up from a preparing room below. The study of anatomy at Padua must have declined since the days of Vesalius if this tiny amphitheatre held all its students; none the less, it is probably the oldest existing anatomical lecture room, and for us it has a very special significance.

Early in his anatomical studies Fabricius had demonstrated the valves in the veins. I show you here two figures, the first, as far as I know, in which these structures are depicted. It does not concern us who first discovered them; they had doubtless been seen before, but Fabricius first recognized them as general structures in the venous system, and he called them little doors—"ostiola."

The quadrangle of the university building at Padua is surrounded by beautiful arcades, the walls and ceilings of which are everywhere covered with the stemmata, or shields, of former students, many of them brilliantly painted. Standing in the arcade on the side of the "quad" opposite the entrance, if one looks on the ceiling immediately above the capital of the second column to the left there is seen the stemma which appears as tailpiece to this chapter, put up by a young Englishman, William Harvey, who had been a student at Padua for four years. He belonged to the "Natio Anglica," of which he was Conciliarius, and took his degree in 1602. Doubtless he had repeatedly seen Fabricius demonstrate the valves of the veins, and he may indeed, as a senior student, have helped in making the very dissections from which the drawings were taken for Fabricius' work, "De Venarum Osteolis," 1603. If one may judge from the character of the teacher's work the sort of instruction the student receives, Harvey must have had splendid training in anatomy. While he was at Padua, the great work of Fabricius, "De Visione, Voce et Auditu" (1600) was published, then the "Tractatus de Oculo Visusque Organo" (1601), and in the last year of his residence Fabricius must have been busy with his studies on the valves of the veins and with his embryology, which appeared in 1604. Late in life, Harvey told Boyle that it was the position of the valves of the veins that induced him to think of a circulation.

Harvey returned to England trained by the best anatomist of his day. In London, he became attached to the College of Physicans, and taking his degree at Cambridge, he began the practice of medicine. He was elected a fellow of the college in 1607 and physician to St. Bartholomew's Hospital in 1609. In 1615 he was appointed Lumleian lecturer to the College of Physicians, and his duties were to hold certain "public anatomies," as they were called, or lectures. We know little or nothing of what Harvey had been doing other than his routine work in the care of the patients at St. Bartholomew's. It was not until April, 1616, that his lectures began. Chance has preserved to us the notes of this first course; the MS. is now in the British Museum and was published in facsimile by the college in 1886.(26)

(26) William Harvey: Prelectiones Anatomiae Universalis, London, J. & A. Churchill, 1886.

The second day lecture, April 17, was concerned with a description of the organs of the thorax, and after a discussion on the structure and action of the heart come the lines:

W. H. constat per fabricam cordis sanguinem per pulmones in Aortam perpetuo transferri, as by two clacks of a water bellows to rayse water constat per ligaturam transitum sanguinis ab arteriis ad venas unde perpetuum sanguinis motum in circulo fieri pulsu cordis.

The illustration will give one an idea of the extraordinarily crabbed hand in which the notes are written, but it is worth while to see the original, for here is the first occasion upon which is laid down in clear and unequivocal words that the blood CIRCULATES. The lecture gave evidence of a skilled anatomist, well versed in the literature from Aristotle to Fabricius. In the MS. of the thorax, or, as he calls it, the "parlour" lecture, there are about a hundred references to some twenty authors. The remarkable thing is that although those lectures were repeated year by year, we have no evidence that they made any impression upon Harvey's contemporaries, so far, at least, as to excite discussions that led to publication. It was not until twelve years later, 1628, that Harvey published in Frankfurt a small quarto volume of seventy-four pages,(27) "De Motu Cordis." In comparison with the sumptuous "Fabrica" of Vesalius this is a trifling booklet; but if not its equal in bulk or typographical beauty (it is in fact very poorly printed), it is its counterpart in physiology, and did for that science what Vesalius had done for anatomy, though not in the same way. The experimental spirit was abroad in the land, and as a student at Padua, Harvey must have had many opportunities of learning the technique of vivisection; but no one before his day had attempted an elaborate piece of experimental work deliberately planned to solve a problem relating to the most important single function of the body. Herein lies the special merit of his work, from every page of which there breathes the modern spirit. To him, as to Vesalius before him, the current views of the movements of the blood were unsatisfactory, more particularly the movements of the heart and arteries, which were regarded as an active expansion by which they were filled with blood, like bellows with air. The question of the transmission of blood through the thick septum and the transference of air and blood from the lungs to the heart were secrets which he was desirous of searching out by means of experiment.

(27) Harvey: Exercitatio Anatomica de Motu Cordis et Sanguinis in Animalibus, Francofurti, 1628.

One or two special points in the work may be referred to as illustrating his method. He undertook first the movements of the heart, a task so truly arduous and so full of difficulties that he was almost tempted to think with Fracastorius that "the movement of the heart was only to be comprehended by God." But after many difficulties he made the following statements: first, that the heart is erected and raises itself up into an apex, and at this time strikes against the breast and the pulse is felt externally; secondly, that it is contracted every-way, but more so at the sides; and thirdly, that grasped in the hand it was felt to become harder at the time of its motion; from all of which actions Harvey drew the very natural conclusion that the activity of the heart consisted in a contraction of its fibres by which it expelled the blood from the ventricles. These were the first four fundamental facts which really opened the way for the discovery of the circulation, as it did away with the belief that the heart in its motion attracts blood into the ventricles, stating on the contrary that by its contraction it expelled the blood and only received it during its period of repose or relaxation. Then he proceeded to study the action of the arteries and showed that their period of diastole, or expansion, corresponded with the systole, or contraction, of the heart, and that the arterial pulse follows the force, frequency and rhythm of the ventricle and is, in fact, dependent upon it. Here was another new fact: that the pulsation in the arteries was nothing else than the impulse of the blood within them. Chapter IV, in which he describes the movements of the auricles and ventricles, is a model of accurate description, to which little has since been added. It is interesting to note that he mentions what is probably auricular fibrillation. He says: "After the heart had ceased pulsating an undulation or palpitation remained in the blood itself which was contained in the right auricle, this being observed so long as it was imbued with heat and spirit." He recognized too the importance of the auricles as the first to move and the last to die. The accuracy and vividness of Harvey's description of the motion of the heart have been appreciated by generations of physiologists. Having grasped this first essential fact, that the heart was an organ for the propulsion of blood, he takes up in Chapters VI and VII the question of the conveyance of the blood from the right side of the heart to the left. Galen had already insisted that some blood passed from the right ventricle to the lungs—enough for their nutrition; but Harvey points out, with Colombo, that from the arrangement of the valves there could be no other view than that with each impulse of the heart blood passes from the right ventricle to the lungs and so to the left side of the heart. How it passed through the lungs was a problem: probably by a continuous transudation. In Chapters VIII and IX he deals with the amount of blood passing through the heart from the veins to the arteries. Let me quote here what he says, as it is of cardinal import:

"But what remains to be said upon the quantity and source of the blood which thus passes, is of a character so novel and unheard of that I not only fear injury to myself from the envy of a few, but I tremble lest I have mankind at large for my enemies, so much doth wont and custom become a second nature. Doctrine once sown strikes deeply its root, and respect for antiquity influences all men. Still the die is cast, and my trust is in my love of truth, and the candour of cultivated minds."(28) Then he goes on to say:

(28) William Harvey: Exercitatio Anatomica de Motu Cordis et Sanguinis in Animalibus, Francofurti, 1628, G. Moreton's facsimile reprint and translation, Canterbury, 1894, p. 48.

"I began to think whether there might not be A MOVEMENT, AS IT WERE, IN A CIRCLE. Now this I afterwards found to be true; and I finally saw that the blood, forced by the action of the left ventricle into the arteries, was distributed to the body at large, and its several parts, in the same manner as it is sent through the lungs, impelled by the right ventricle into the pulmonary artery, and that it then passed through the veins and along the vena cava, and so round to the left ventricle in the manner already indicated."(29)

(29) Ibid. p. 49.

The experiments dealing with the transmission of blood in the veins are very accurate, and he uses the old experiment that Fabricius had employed to show the valves, to demonstrate that the blood in the veins flows towards the heart. For the first time a proper explanation of the action of the valves is given. Harvey had no appreciation of how the arteries and veins communicated with each other. Galen, you may remember, recognized that there were anastomoses, but Harvey preferred the idea of filtration.

The "De Motu Cordis" constitutes a unique piece of work in the history of medicine. Nothing of the same type had appeared before. It is a thoroughly sensible, scientific study of a definite problem, the solution of which was arrived at through the combination of accurate observation and ingenious experiment. Much misunderstanding has arisen in connection with Harvey's discovery of the circulation of the blood. He did not discover that the blood moved,—that was known to Aristotle and to Galen, from both of whom I have given quotations which indicate clearly that they knew of its movement,—but at the time of Harvey not a single anatomist had escaped from the domination of Galen's views. Both Servetus and Colombo knew of the pulmonary circulation, which was described by the former in very accurate terms. Cesalpinus, a great name in anatomy and botany, for whom is claimed the discovery of the circulation, only expressed the accepted doctrines in the following oft-quoted phrase:

"We will now consider how the attraction of aliment and the process of nutrition takes place in plants; for in animals we see the aliment brought through the veins to the heart, as to a laboratory of innate heat, and, after receiving there its final perfection, distributed through the arteries to the body at large, by the agency of the spirits produced from this same aliment in the heart."(30) There is nothing in this but Galen's view, and Cesalpinus believed, as did all his contemporaries, that the blood was distributed through the body by the vena cava and its branches for the nourishment of all its parts.(*) To those who have any doubts as to Harvey's position in this matter I would recommend the reading of the "De Motu Cordis" itself, then the various passages relating to the circulation from Aristotle to Vesalius. Many of these can be found in the admirable works of Dalton, Flourens, Richet and Curtis.(31) In my Harveian Oration for 1906(32) I have dealt specially with the reception of the new views, and have shown how long it was before the reverence for Galen allowed of their acceptance. The University of Paris opposed the circulation of the blood for more than half a century after the appearance of the "De Motu Cordis."

(30) De Plantis, Lib I, cap. 2.

(*) Cesalpinus has also a definite statement of the circlewise process.—Ed.

(31) J. C. Dalton Doctrines of the Circulation, Philadelphia, 1884; Flourens Histoire de la decouverte de la circulation du sang, 2d ed., Paris, 1857; Charles Richet Harvey, la circulation du sang, Paris, 1879; John G. Curtis Harvey's views on the use of Circulation, etc., New York, 1916.

(32) Osler An Alabama Student and Other Biographical Essays, Oxford, 1908, p. 295.

To summarize—until the seventeenth century there were believed to be two closed systems in the circulation, (1) the natural, containing venous blood, had its origin in the liver from which, as from a fountain, the blood continually ebbed and flowed for the nourishment of the body; (2) the vital, containing another blood and the spirits, ebbed and flowed from the heart, distributing heat and life to all parts. Like a bellows the lungs fanned and cooled this vital blood. Here and there we find glimmering conceptions of a communication between these systems, but practically all teachers believed that the only one of importance was through small pores in the wall separating the two sides of the heart. Observation—merely looking at and thinking about things—had done all that was possible, and further progress had to await the introduction of a new method, viz., experiment. Galen, it is true, had used this means to show that the arteries of the body contained blood and not air. The day had come when men were no longer content with accurate description and with finely spun theories and dreams. It was reserved for the immortal Harvey to put into practice the experimental method by which he demonstrated conclusively that the blood moved in a circle. The "De Motu Cordis" marks the final break of the modern spirit with the old traditions. It took long for men to realize the value of this "inventum mirabile" used so effectively by the Alexandrians—by Galen—indeed, its full value has only been appreciated within the past century. Let me quote a paragraph from my Harveian Oration.(33) "To the age of the hearer, in which men had heard and heard only, had succeeded the age of the eye in which men had seen and had been content only to see. But at last came the age of the hand—the thinking, devising, planning hand, the hand as an instrument of the mind, now re-introduced into the world in a modest little monograph from which we may date the beginning of experimental medicine."

(33) Osler: An Alabama Student, etc., pp. 329-330.

Harvey caught the experimental spirit in Italy, with brain, eye and hand as his only aids, but now an era opened in which medicine was to derive an enormous impetus from the discovery of instruments of precision. "The new period in the development of the natural sciences, which reached its height in the work of such men as Galileo, Gilbert and Kepler, is chiefly characterized by the invention of very important instruments for aiding and intensifying the perceptions of the senses, by means of which was gained a much deeper insight into the phenomena than had hitherto been possible. Such instruments as the earlier ages possessed were little more than primitive hand-made tools. Now we find a considerable number of scientifically made instruments deliberately planned for purposes of special research, and as it were, on the threshold of the period stand two of the most important, the compound microscope and the telescope. The former was invented about 1590 and the latter about 1608."(34) It was a fellow professor of the great genius Galileo who attempted to put into practice the experimental science of his friend. With Sanctorius began the studies of temperature, respiration and the physics of the circulation. The memory of this great investigator has not been helped by the English edition of his "De Statica Medicina," not his best work, with a frontispiece showing the author in his dietetic balance. Full justice has been done to him by Dr. Weir Mitchell in an address as president of the Congress of Physicians and Surgeons, 1891.(35) Sanctorius worked with a pulsilogue devised for him by Galileo, with which he made observations on the pulse. He is said to have been the first to put in use the clinical thermometer. His experiments on insensible perspiration mark him as one of the first modern physiologists.

(34) Dannemann: Die Naturwissenschaften in ihrer Entwickelung..., Vol. II, p. 7, Leipzig, 1911.

(35) See Transactions Congress Physicians and Surgeons, 1891, New Haven, 1892, II, 159-181.

But neither Sanctorius nor Harvey had the immediate influence upon their contemporaries which the novel and stimulating character of their work justified. Harvey's great contemporary, Bacon, although he lost his life in making a cold storage experiment, did not really appreciate the enormous importance of experimental science. He looked very coldly upon Harvey's work. It was a philosopher of another kidney, Rene Descartes, who did more than anyone else to help men to realize the value of the better way which Harvey had pointed out. That the beginning of wisdom was in doubt, not in authority, was a novel doctrine in the world, but Descartes was no armchair philosopher, and his strong advocacy and practice of experimentation had a profound influence in directing men to "la nouvelle methode." He brought the human body, the earthly machine, as he calls it, into the sphere of mechanics and physics, and he wrote the first text-book of physiology, "De l'Homme." Locke, too, became the spokesman of the new questioning spirit, and before the close of the seventeenth century, experimental research became all the mode. Richard Lower, Hooke and Hales were probably more influenced by Descartes than by Harvey, and they made notable contributions to experimental physiology in England. Borelli, author of the famous work on "The Motion of Animals" (Rome, 1680-1681), brought to the study of the action of muscles a profound knowledge of physics and mathematics and really founded the mechanical, or iatromechanical school. The literature and the language of medicine became that of physics and mechanics: wheels and pulleys, wedges, levers, screws, cords, canals, cisterns, sieves and strainers, with angles, cylinders, celerity, percussion and resistance, were among the words that now came into use in medical literature. Withington quotes a good example in a description by Pitcairne, the Scot who was professor of medicine at Leyden at the end of the seventeenth century. "Life is the circulation of the blood. Health is its free and painless circulation. Disease is an abnormal motion of the blood, either general or local. Like the English school generally, he is far more exclusively mechanical than are the Italians, and will hear nothing of ferments or acids, even in digestion. This, he declares, is a purely mechanical process due to heat and pressure, the wonderful effects of which may be seen in Papin's recently invented 'digester.' That the stomach is fully able to comminute the food may be proved by the following calculation. Borelli estimates the power of the flexors of the thumb at 3720 pounds, their average weight being 122 grains. Now, the average weight of the stomach is eight ounces, therefore it can develop a force of 117,088 pounds, and this may be further assisted by the diaphragm and abdominal muscles the power of which, estimated in the same way, equals 461,219 pounds! Well may Pitcairne add that this force is not inferior to that of any millstone."(36) Paracelsus gave an extraordinary stimulus to the study of chemistry and more than anyone else he put the old alchemy on modern lines. I have already quoted his sane remark that its chief service is in seeking remedies. But there is another side to this question. If, as seems fairly certain, the Basil Valentine whose writings were supposed to have inspired Paracelsus was a hoax and his works were made up in great part from the writings of Paracelsus, then to our medical Luther, and not to the mythical Benedictine monk, must be attributed a great revival in the search for the Philosopher's Stone, for the Elixir of Life, for a universal medicine, for the perpetuum mobile and for an aurum potabile.(37) I reproduce, almost at random, a page from the fifth and last part of the last will and testament of Basil Valentine (London, 1657), from which you may judge the chemical spirit of the time.

(36) Withington: Medical History from the Earliest Times, London, 1891, Scientific Press, p. 317.

(37) See Professor Stillman on the Basil Valentine hoax, Popular Science Monthly, New York, 1919, LXXXI, 591-600.

Out of the mystic doctrines of Paracelsus arose the famous "Brothers of the Rosy Cross." "The brotherhood was possessed of the deepest knowledge and science, the transmutation of metals, the perpetuum mobile and the universal medicine were among their secrets; they were free from sickness and suffering during their lifetime, though subject finally to death."(38)

(38) Ferguson: Bibliotheca Chemica, Vol. II, p. 290. For an account of Fludd and the English Rosicrucians see Craven's Life of Fludd, Kirkwall, 1902.

A school of a more rational kind followed directly upon the work of Paracelsus, in which the first man of any importance was Van Helmont. The Paracelsian Archeus was the presiding spirit in living creatures, and worked through special local ferments, by which the functions of the organs are controlled. Disease of any part represents a strike on the part of the local Archeus, who refuses to work. Though full of fanciful ideas, Van Helmont had the experimental spirit and was the first chemist to discover the diversity of gases. Like his teacher, he was in revolt against the faculty, and he has bitter things to say of physicians. He got into trouble with the Church about the magnetic cure of wounds, as no fewer than twenty-seven propositions incompatible with the Catholic faith were found in his pamphlet (Ferguson). The Philosophus per ignem, Toparcha in Merode, Royenborch, as he is styled in certain of his writings, is not an easy man to tackle. I show the title-page of the "Ortus Medicinae," the collection of his works by his son. As with the pages of Paracelsus, there are many gems to be dug out. The counterblast against bleeding was a useful protest, and to deny in toto its utility in fever required courage—a quality never lacking in the Father of Modern Chemistry, as he has been called.

A man of a very different type, a learned academic, a professor of European renown, was Daniel Sennert of Wittenberg, the first to introduce the systematic teaching of chemistry into the curriculum, and who tried to harmonize the Galenists and Paracelsians. Franciscus Sylvius, a disciple of Van Helmont, established the first chemical laboratory in Europe at Leyden, and to him is due the introduction of modern clinical teaching. In 1664 he writes: "I have led my pupils by the hand to medical practice, using a method unknown at Leyden, or perhaps elsewhere, i.e., taking them daily to visit the sick at the public hospital. There I have put the symptoms of disease before their eyes; have let them hear the complaints of the patients, and have asked them their opinions as to the causes and rational treatment of each case, and the reasons for those opinions. Then I have given my own judgment on every point. Together with me they have seen the happy results of treatment when God has granted to our cares a restoration of health; or they have assisted in examining the body when the patient has paid the inevitable tribute to death."(39)

(39) Withington: Medical History from the Earliest Times, London, 1894, pp. 312-313.

Glauber, Willis, Mayow, Lemery, Agricola and Stahl led up to Robert Boyle, with whom modern chemistry may be said to begin. Even as late as 1716, Lady Mary Wortley Montagu in Vienna found that all had transferred their superstitions from religion to chemistry; "scarcely a man of opulence or fashion that has not an alchemist in his service." To one scientific man of the period I must refer as the author of the first scientific book published in England. Dryden sings:

Gilbert shall live till load-stones cease to draw Or British fleets the boundless ocean awe.

And the verse is true, for by the publication in 1600 of the "De Magnete" the science of electricity was founded. William Gilbert was a fine type of the sixteenth-century physician, a Colchester man, educated at St. John's College, Cambridge. Silvanus Thompson says: "He is beyond question rightfully regarded as the Father of Electric Science. He founded the entire subject of Terrestrial Magnetism. He also made notable contributions to Astronomy, being the earliest English expounder of Copernicus. In an age given over to metaphysical obscurities and dogmatic sophistry, he cultivated the method of experiment and of reasoning from observation, with an insight and success which entitles him to be regarded as the father of the inductive method. That method, so often accredited to Bacon, Gilbert was practicing years before him."(40)

(40) Silvanus P. Thompson: Gilbert of Colchester, Father of Electrical Science, London, Chiswick Press, 1903, p. 3.



CHAPTER V — THE RISE AND DEVELOPMENT OF MODERN MEDICINE

THE middle of the seventeenth century saw the profession thus far on its way—certain objective features of disease were known, the art of careful observation had been cultivated, many empirical remedies had been discovered, the coarser structure of man's body had been well worked out, and a good beginning had been made in the knowledge of how the machinery worked—nothing more. What disease really was, where it was, how it was caused, had not even begun to be discussed intelligently.

An empirical discovery of the first importance marks the middle of the century. The story of cinchona is of special interest, as it was the first great specific in disease to be discovered. In 1638, the wife of the Viceroy of Peru, the Countess of Chinchon, lay sick of an intermittent fever in the Palace of Lima. A friend of her husband's, who had become acquainted with the virtues, in fever, of the bark of a certain tree, sent a parcel of it to the Viceroy, and the remedy administered by her physician, Don Juan del Vego, rapidly effected a cure. In 1640, the Countess returned to Spain, bringing with her a supply of quina bark, which thus became known in Europe as "the Countess's Powder" (pulvis Comitissae). A little later, her doctor followed, bringing additional quantities. Later in the century, the Jesuit Fathers sent parcels of the bark to Rome, whence it was distributed to the priests of the community and used for the cure of ague; hence the name of "Jesuits' bark." Its value was early recognized by Sydenham and by Locke. At first there was a great deal of opposition, and the Protestants did not like it because of its introduction by the Jesuits. The famous quack, Robert Talbor, sold the secret of preparing quinquina to Louis XIV in 1679 for two thousand louis d'or, a pension and a title. That the profession was divided in opinion on the subject was probably due to sophistication, or to the importation of other and inert barks. It was well into the eighteenth century before its virtues were universally acknowledged. The tree itself was not described until 1738, and Linnaeus established the genus "Chinchona" in honor of the Countess.(1)

(1) Clements R. Markham: Peruvian Bark, John Murray, London, 1880; Memoir of the Lady Anna di Osoria, Countess of Chinchona and Vice-Queen of Peru, 1874.

A step in advance followed the objective study of the changes wrought in the body by disease. To a few of these the anatomists had already called attention. Vesalius, always keen in his description of aberrations from the normal, was one of the first to describe internal aneurysm. The truth is, even the best of men had little or no appreciation of the importance of the study of these changes. Sydenham scoffs at the value of post-mortems.

Again we have to go back to Italy for the beginning of these studies, this time to Florence, in the glorious days of Lorenzo the Magnificent. The pioneer now is not a professor but a general practitioner, Antonio Benivieni, of whom we know very little save that he was a friend of Marsilio Ficino and of Angelo Poliziano, and that he practiced in Florence during the last third of the fifteenth century, dying in 1502. Through associations with the scholars of the day, he had become a student of Greek medicine and he was not only a shrewd and accurate observer of nature but a bold and successful practitioner. He had formed the good habit of making brief notes of his more important cases, and after his death these were found by his brother Jerome and published in 1507.(2) This book has a rare value as the record of the experience of an unusually intelligent practitioner of the period. There are in all 111 observations, most of them commendably brief. The only one of any length deals with the new "Morbus Gallicus," of which, in the short period between its appearance and Benivieni's death, he had seen enough to leave a very accurate description; and it is interesting to note that even in those early days mercury was employed for its cure. The surgical cases are of exceptional interest, and No. 38 refers to a case of angina for which he performed a successful operation. This is supposed to have been a tracheotomy, and if so, it is the first in the fourteen centuries that had elapsed since the days of Antyllus.(3) There are other important cases which show that he was a dexterous and fearless surgeon. But the special interest of the work for us is that, for the first time in modern literature, we have reports of post-mortem examinations made specifically with a view to finding out the exact cause of death. Among the 111 cases, there are post-mortem records of cases of gallstones, abscess of the mesentery, thrombosis of the mesenteric veins, several cases of heart disease, senile gangrene and one of cor villosum. From no other book do we get so good an idea of a practitioner's experience at this period; the notes are plain and straightforward, and singularly free from all theoretical and therapeutic vagaries. He gives several remarkable instances of faith healing.

(2) De abditis nonnullis ac mirandis morborum et sanationum causis. 8th, Florence, Gandhi, 1507.

(3) Possibly it was only a case of angina Ludovici, or retro-pharyngeal abscess.

To know accurately the anatomical changes that take place in disease is of importance both for diagnosis and for treatment. The man who created the science, who taught us to think anatomically of disease, was Morgagni, whose "De sedibus et causis morborum per anatomen indagatis"(4) is one of the great books in our literature. During the seventeenth century, the practice of making post-mortem examinations had extended greatly, and in the "Sepulchretum anatomicum" of Bonetus (1679), these scattered fragments are collected.(5) But the work of Morgagni is of a different type, for in it are the clinical and anatomical observations of an able physician during a long and active life. The work had an interesting origin. A young friend interested in science and in medicine was fond of discoursing with Morgagni about his preceptors, particularly Valsalva and Albertini, and sometimes the young man inquired about Morgagni's own observations and thoughts. Yielding to a strong wish, Morgagni consented to write his young friend familiar letters describing his experiences. I am sorry that Morgagni does not mention the name of the man to whom we are so much indebted, and who, he states, was so pleased with the letters that he continually solicited him to send more and more "till he drew me on so far as the seventieth; . . . when I begged them of him in order to revise their contents; he did not return them, till he had made me solemnly promise, that I would not abridge any part thereof" (Preface).

(4) Venice, 1761.

(5) Boerhaave remarked that if a man wished to deserve or get a medical degree from ONE medical author let it be this. (James Atkinson: Medical Bibliography, 1834, 268.)

Born in 1682, Morgagni studied at Bologna under Valsalva and Albertini. In 1711, he was elected professor of medicine at Padua. He published numerous anatomical observations and several smaller works of less importance. The great work which has made his name immortal in the profession, appeared in his eightieth year, and represents the accumulated experience of a long life. Though written in the form of letters, the work is arranged systematically and has an index of exceptional value. From no section does one get a better idea of the character and scope of the work than from that relating to the heart and arteries—affections of the pericardium, diseases of the valves, ulceration, rupture, dilation and hypertrophy and affections of the aorta are very fully described. The section on aneurysm of the aorta remains one of the best ever written. It is not the anatomical observations alone that make the work of unusual value, but the combination of clinical with anatomical records. What could be more correct than this account of angina pectoris—probably the first in the literature? "A lady forty-two years of age, who for a long time, had been a valetudinarian, and within the same period, on using pretty quick exercise of body, she was subject to attacks of violent anguish in the upper part of the chest on the left side, accompanied with a difficulty of breathing, and numbness of the left arm; but these paroxysms soon subsided when she ceased from exertion. In these circumstances, but with cheerfulness of mind, she undertook a journey from Venice, purposing to travel along the continent, when she was seized with a paroxysm, and died on the spot. I examined the body on the following day.... The aorta was considerably dilated at its curvature; and, in places, through its whole tract, the inner surface was unequal and ossified. These appearances were propagated into the arteria innominata. The aortic valves were indurated...." He remarks, "The delay of blood in the aorta, in the heart, in the pulmonary vessels, and in the vena cave, would occasion the symptoms of which the woman complained during life; namely, the violent uneasiness, the difficulty of breathing, and the numbness of the arm."(6)

(6) Cooke's Morgagni, Vol. 1, pp. 417-418. I cannot too warmly commend to young clinicians the reading of Morgagni. English editions are available—Alexander's three-volume translation of 1769 and Cooke's Abridgement (London, 1822), of which there was an American edition published in Boston in 1824.

Morgagni's life had as much influence as his work. In close correspondence with the leading men of the day, with the young and rising teachers and workers, his methods must have been a great inspiration; and he came just at the right time. The profession was literally ravaged by theories, schools and systems—iatromechanics, iatrochemistry, humoralism, the animism of Stahl, the vitalistic doctrines of Van Helmont and his followers—and into this metaphysical confusion Morgagni came like an old Greek with his clear observation, sensible thinking and ripe scholarship. Sprengel well remarks that "it is hard to say whether one should admire most his rare dexterity and quickness in dissection, his unimpeachable love of truth and justice in his estimation of the work of others, his extensive scholarship and rich classical style or his downright common sense and manly speech."

Upon this solid foundation the morbid anatomy of modern clinical medicine was built. Many of Morgagni's contemporaries did not fully appreciate the change that was in progress, and the value of the new method of correlating the clinical symptoms and the morbid appearances. After all, it was only the extension of the Hippocratic method of careful observation—the study of facts from which reasonable conclusions could be drawn. In every generation there had been men of this type—I dare say many more than we realize—men of the Benivieni character, thoroughly practical, clear-headed physicians. A model of this sort arose in England in the middle of the seventeenth century, Thomas Sydenham (1624-1689), who took men back to Hippocrates, just as Harvey had led them back to Galen. Sydenham broke with authority and went to nature. It is extraordinary how he could have been so emancipated from dogmas and theories of all sorts. He laid down the fundamental proposition, and acted upon it, that "all disease could be described as natural history." To do him justice we must remember, as Dr. John Brown says, "in the midst of what a mass of errors and prejudices, of theories actively mischievous, he was placed, at a time when the mania of hypothesis was at its height, and when the practical part of his art was overrun and stultified by vile and silly nostrums" ("Horae Subsecivae," Vol. I, 4th ed., Edinburgh, 1882, p. 40).

Listen to what he says upon the method of the study of medicine: "In writing therefore, such a natural history of diseases, every merely philosophical hypothesis should be set aside, and the manifest and natural phenomena, however minute, should be noted with the utmost exactness. The usefulness of this procedure cannot be easily overrated, as compared with the subtle inquiries and trifling notions of modern writers, for can there be a shorter, or indeed any other way of coming at the morbific causes, or discovering the curative indications than by a certain perception of the peculiar symptoms? By these steps and helps it was that the father of physic, the great Hippocrates, came to excel, his theory being no more than an exact description or view of nature. He found that nature alone often terminates diseases, and works a cure with a few simple medicines, and often enough with no medicines at all."

Towards the end of the century many great clinical teachers arose, of whom perhaps the most famous was Boerhaave, often spoken of as the Dutch Hippocrates, who inspired a group of distinguished students. I have already referred to the fact that Franciscus Sylvius at Leyden was the first among the moderns to organize systematic clinical teaching. Under Boerhaave, this was so developed that to this Dutch university students flocked from all parts of Europe. After teaching botany and chemistry, Boerhaave succeeded to the chair of physic in 1714. With an unusually wide general training, a profound knowledge of the chemistry of the day and an accurate acquaintance with all aspects of the history of the profession, he had a strongly objective attitude of mind towards disease, following closely the methods of Hippocrates and Sydenham. He adopted no special system, but studied disease as one of the phenomena of nature. His clinical lectures, held bi-weekly, became exceedingly popular and were made attractive not less by the accuracy and care with which the cases were studied than by the freedom from fanciful doctrines and the frank honesty of the man. He was much greater than his published work would indicate, and, as is the case with many teachers of the first rank, his greatest contributions were his pupils. No other teacher of modern times has had such a following. Among his favorite pupils may be mentioned Haller, the physiologist, and van Swieten and de Haen, the founders of the Vienna school.

In Italy, too, there were men who caught the new spirit, and appreciated the value of combining morbid anatomy with clinical medicine. Lancisi, one of the early students of disease of the heart, left an excellent monograph on the subject, and was the first to call special attention to the association of syphilis with cardio-vascular disease. A younger contemporary of his at Rome, Baglivi, was unceasing in his call to the profession to return to Hippocratic methods, to stop reading philosophical theories and to give up what he calls the "fatal itch" to make systems.

The Leyden methods of instruction were carried far and wide throughout Europe; into Edinburgh by John Rutherford, who began to teach at the Royal Infirmary in 1747, and was followed by Whytt and by Cullen; into England by William Saunders of Guy's Hospital. Unfortunately the great majority of clinicians could not get away from the theoretical conceptions of disease, and Cullen's theory of spasm and atony exercised a profound influence on practice, particularly in this country, where it had the warm advocacy of Benjamin Rush. Even more widespread became the theories of a pupil of Cullen's, John Brown, who regarded excitability as the fundamental property of all living creatures: too much of this excitability produced what were known as sthenic maladies, too little, asthenic; on which principles practice was plain enough. Few systems of medicine have ever stirred such bitter controversy, particularly on the Continent, and in Charles Creighton's account of Brown(7) we read that as late as 1802 the University of Gottingen was so convulsed by controversies as to the merits of the Brunonian system that contending factions of students in enormous numbers, not unaided by the professors, met in combat in the streets on two consecutive days and had to be dispersed by a troop of Hanoverian horse.

(7) Dictionary of National Biography, London, 1886, VII, 14-17.

But the man who combined the qualities of Vesalius, Harvey and Morgagni in an extraordinary personality was John Hunter. He was, in the first place, a naturalist to whom pathological processes were only a small part of a stupendous whole, governed by law, which, however, could never be understood until the facts had been accumulated, tabulated and systematized. By his example, by his prodigious industry, and by his suggestive experiments he led men again into the old paths of Aristotle, Galen and Harvey. He made all thinking physicians naturalists, and he lent a dignity to the study of organic life, and re-established a close union between medicine and the natural sciences. Both in Britain and Greater Britain, he laid the foundation of the great collections and museums, particularly those connected with the medical schools. The Wistar-Horner and the Warren Museums in this country originated with men greatly influenced by Hunter. He was, moreover, the intellectual father of that interesting group of men on this side of the Atlantic who, while practising as physicians, devoted much time and labor to the study of natural history; such men as Benjamin Smith Barton, David Hossack, Jacob Bigelow, Richard Harlan, John D. Godman, Samuel George Morton, John Collins Warren, Samuel L. Mitchill and J. Ailken Meigs. He gave an immense impetus in Great Britain to the study of morbid anatomy, and his nephew, Matthew Baillie, published the first important book on the subject in the English language.

Before the eighteenth century closed practical medicine had made great advance. Smallpox, though not one of the great scourges like plague or cholera, was a prevalent and much dreaded disease, and in civilized countries few reached adult life without an attack. Edward Jenner, a practitioner in Gloucestershire, and the pupil to whom John Hunter gave the famous advice: "Don't think, try!" had noticed that milkmaids who had been infected with cowpox from the udder of the cow were insusceptible to smallpox. I show you here the hand of Sarah Nelmes with cowpox, 1796. A vague notion had prevailed among the dairies from time immemorial that this disease was a preventive of the smallpox. Jenner put the matter to the test of experiment. Let me quote here his own words: "The first experiment was made upon a lad of the name of Phipps, in whose arm a little vaccine virus was inserted, taken from the hand of a young woman who had been accidentally infected by a cow. Notwithstanding the resemblance which the pustule, thus excited on the boy's arm, bore to variolous inoculation, yet as the indisposition attending it was barely perceptible, I could scarcely persuade myself the patient was secure from the Small Pox. However, on his being inoculated some months afterwards, it proved that he was secure."(8) The results of his experiments were published in a famous small quarto volume in 1798.(*) From this date, smallpox has been under control. Thanks to Jenner, not a single person in this audience is pockmarked! A hundred and twenty-five years ago, the faces of more than half of you would have been scarred. We now know the principle upon which protection is secured: an active acquired immunity follows upon an attack of a disease of a similar nature. Smallpox and cowpox are closely allied and the substances formed in the blood by the one are resistant to the virus of the other. I do not see how any reasonable person can oppose vaccination or decry its benefits. I show you the mortality figures(9) of the Prussian Army and of the German Empire. A comparison with the statistics of the armies of other European countries in which revaccination is not so thoroughly carried out is most convincing of its efficacy.

(8) Edward Jenner: The Origin of the Vaccine Inoculation, London, 1801.

(*) Reprinted by Camac: Epoch-making Contributions to Medicine, etc., 1909.—Ed.

(9) Jockmann: Pocken und Vaccinationlehre, 1913.

The early years of the century saw the rise of modern clinical medicine in Paris. In the art of observation men had come to a standstill. I doubt very much whether Corvisart in 1800 was any more skilful in recognizing a case of pneumonia than was Aretaeus in the second century A. D. But disease had come to be more systematically studied; special clinics were organized, and teaching became much more thorough. Anyone who wishes to have a picture of the medical schools in Europe in the first few years of the century, should read the account of the travels of Joseph Frank of Vienna.(10) The description of Corvisart is of a pioneer in clinical teaching whose method remains in vogue today in France—the ward visit, followed by a systematic lecture in the amphitheatre. There were still lectures on Hippocrates three times a week, and bleeding was the principal plan of treatment: one morning Frank saw thirty patients, out of one hundred and twelve, bled! Corvisart was the strong clinician of his generation, and his accurate studies on the heart were among the first that had concentrated attention upon a special organ. To him, too, is due the reintroduction of the art of percussion in internal disease discovered by Auenbrugger in 1761.

(10) Joseph Frank: Reise nach Paris (etc.), Wien, 1804-05.

The man who gave the greatest impetus to the study of scientific medicine at this time was Bichat, who pointed out that the pathological changes in disease were not so much in organs as in tissues. His studies laid the foundation of modern histology. He separated the chief constituent elements of the body into various tissues possessing definite physical and vital qualities. "Sensibility and contractability are the fundamental qualities of living matter and of the life of our tissues. Thus Bichat substituted for vital forces 'vital properties,' that is to say, a series of vital forces inherent in the different tissues."(11) His "Anatomic Generale," published in 1802, gave an extraordinary stimulus to the study of the finer processes of disease, and his famous "Recherches sur la Vie et sur la Mort" (1800) dealt a death-blow to old iatromechanical and iatrochemical views. His celebrated definition may be quoted: "La vie est l'ensemble des proprietes vitales qui resistent aux proprietes physiques, ou bien la vie est l'ensemble des fonctions qui resistent a la mort." (Life is the sum of the vital properties that withstand the physical properties, or, life is the sum of the functions that withstand death.) Bichat is another pathetic figure in medical history. His meteoric career ended in his thirty-first year: he died a victim of a post-mortem wound infection. At his death, Corvisart wrote Napoleon: "Bichat has just died at the age of thirty. That battlefield on which he fell is one which demands courage and claims many victims. He has advanced the science of medicine. No one at his age has done so much so well."

(11) E. Boinet: Les doctrines medicules, leur evolution, Paris, 1907, pp. 85-86.

It was a pupil of Corvisart, Rene Theophile Laennec, who laid the foundation of modern clinical medicine. The story of his life is well known. A Breton by birth, he had a hard, up-hill struggle as a young man—a struggle of which we have only recently been made aware by the publication of a charming book by Professor Rouxeau of Nantes—"Laennec avant 1806." Influenced by Corvisart, he began to combine the accurate study of cases in the wards with anatomical investigations in the dead-house. Before Laennec, the examination of a patient had been largely by sense of sight, supplemented by that of touch, as in estimating the degree of fever, or the character of the pulse. Auenbrugger's "Inventum novum" of percussion, recognized by Corvisart, extended the field; but the discovery of auscultation by Laennec, and the publication of his work—"De l'Auscultation Mediate," 1819,—marked an era in the study of medicine. The clinical recognition of individual diseases had made really very little progress; with the stethoscope begins the day of physical diagnosis. The clinical pathology of the heart, lungs and abdomen was revolutionized. Laennec's book is in the category of the eight or ten greatest contributions to the science of medicine.(*) His description of tuberculosis is perhaps the most masterly chapter in clinical medicine. This revolution was effected by a simple extension of the Hippocratic method from the bed to the dead-house, and by correlating the signs and symptoms of a disease with its anatomical appearances.

(*) John Forbes's translation of Auenbrugger and part of his translation of Lacnnec are reprinted in Camac's Epoch-making Contributions, etc., 1909.—Ed.

The pupils and successors of Corvisart—Bayle, Andral, Bouillaud, Chomel, Piorry, Bretonneau, Rayer, Cruveilhier and Trousseau—brought a new spirit into the profession. Everywhere the investigation of disease by clinical-pathological methods widened enormously the diagnostic powers of the physician. By this method Richard Bright, in 1836, opened a new chapter on the relation of disease of the kidney to dropsy, and to albuminous urine. It had already been shown by Blackwell and by Wells, the celebrated Charleston (S.C.) physician, in 1811, that the urine contained albumin in many cases of dropsy, but it was not until Bright began a careful investigation of the bodies of patients who had presented these symptoms, that he discovered the association of various forms of disease of the kidney with anasarca and albuminous urine. In no direction was the harvest of this combined study more abundant than in the complicated and confused subject of fever. The work of Louis and of his pupils, W.W. Gerhard and others, revealed the distinction between typhus and typhoid fever, and so cleared up one of the most obscure problems in pathology. By Morgagni's method of "anatomical thinking," Skoda in Vienna, Schonlein in Berlin, Graves and Stokes in Dublin, Marshall Hall, C. J. B. Williams and many others introduced the new and exact methods of the French and created a new clinical medicine. A very strong impetus was given by the researches of Virchow on cellular pathology, which removed the seats of disease from the tissues, as taught by Bichat, to the individual elements, the cells. The introduction of the use of the microscope in clinical work widened greatly our powers of diagnosis, and we obtained thereby a very much clearer conception of the actual processes of disease. In another way, too, medicine was greatly helped by the rise of experimental pathology, which had been introduced by John Hunter, was carried along by Magendie and others, and reached its culmination in the epoch-making researches of Claude Bernard. Not only were valuable studies made on the action of drugs, but also our knowledge of cardiac pathology was revolutionized by the work of Traube, Cohnheim and others. In no direction did the experimental method effect such a revolution as in our knowledge of the functions of the brain. Clinical neurology, which had received a great impetus by the studies of Todd, Romberg, Lockhart Clarke, Duchenne and Weir Mitchell, was completely revolutionized by the experimental work of Hitzig, Fritsch and Ferrier on the localization of functions in the brain. Under Charcot, the school of French neurologists gave great accuracy to the diagnosis of obscure affections of the brain and spinal cord, and the combined results of the new anatomical, physiological and experimental work have rendered clear and definite what was formerly the most obscure and complicated section of internal medicine. The end of the fifth decade of the century is marked by a discovery of supreme importance. Humphry Davy had noted the effects of nitrous oxide. The exhilarating influence of sulphuric ether had been casually studied, and Long of Georgia had made patients inhale the vapor until anaesthetic and had performed operations upon them when in this state; but it was not until October 16, 1846, in the Massachusetts General Hospital, that Morton, in a public operating room, rendered a patient insensible with ether and demonstrated the utility of surgical anaesthesia. The rival claims of priority no longer interest us, but the occasion is one of the most memorable in the history of the race. It is well that our colleagues celebrate Ether Day in Boston—no more precious boon has ever been granted to suffering humanity.(*)

(*) Cf. Osler: Proc. Roy. Soc. Med., XI, Sect. Hist. Med., pp. 65-69, 1918, or, Annals Med. Hist., N.Y., I, 329-332. Cf. also Morton's publications reprinted in Camac's book cited above.—Ed.

In 1857, a young man, Louis Pasteur, sent to the Lille Scientific Society a paper on "Lactic Acid Fermentation" and in December of the same year presented to the Academy of Sciences in Paris a paper on "Alcoholic Fermentation" in which he concluded that "the deduplication of sugar into alcohol and carbonic acid is correlative to a phenomenon of life." A new era in medicine dates from those two publications. The story of Pasteur's life should be read by every student.(*) It is one of the glories of human literature, and, as a record of achievement and of nobility of character, is almost without an equal.

(*) Osler wrote a preface for the 1911 English edition of the Life by Vallery-Radot.—Ed.

At the middle of the last century we did not know much more of the actual causes of the great scourges of the race, the plagues, the fevers and the pestilences, than did the Greeks. Here comes Pasteur's great work. Before him Egyptian darkness; with his advent a light that brightens more and more as the years give us ever fuller knowledge. The facts that fevers were catching, that epidemics spread, that infection could remain attached to articles of clothing, etc., all gave support to the view that the actual cause was something alive, a contagium vivum. It was really a very old view, the germs of which may be found in the Fathers, but which was first clearly expressed—so far as I know—by Fracastorius, the Veronese physician, in the sixteenth century, who spoke of the seeds of contagion passing from one person to another;(12) and he first drew a parallel between the processes of contagion and the fermentation of wine. This was more than one hundred years before Kircher, Leeuwenhoek and others began to use the microscope and to see animalcula, etc., in water, and so give a basis for the "infinitely little" view of the nature of disease germs. And it was a study of the processes of fermentation that led Pasteur to the sure ground on which we now stand.

(12) Varro, in De Re Rustica, Bk. I, 12 (circa 40 B.C.), speaks of minute organisms which the eye cannot see and which enter the body and cause disease.

Out of these researches arose a famous battle which kept Pasteur hard at work for four or five years—the struggle over spontaneous generation. It was an old warfare, but the microscope had revealed a new world, and the experiments on fermentation had lent great weight to the omne vivum ex ovo doctrine. The famous Italians, Redi and Spallanzani, had led the way in their experiments, and the latter had reached the conclusion that there is no vegetable and no animal that has not its own germ. But heterogenesis became the burning question, and Pouchet in France, and Bastian in England, led the opposition to Pasteur. The many famous experiments carried conviction to the minds of scientific men, and destroyed forever the old belief in spontaneous generation. All along, the analogy between disease and fermentation must have been in Pasteur's mind; and then came the suggestion, "What would be most desirable is to push those studies far enough to prepare the road for a serious research into the origin of various diseases." If the changes in lactic, alcoholic and butyric fermentations are due to minute living organisms, why should not the same tiny creatures make the changes which occur in the body in the putrid and suppurative diseases? With an accurate training as a chemist, having been diverted in his studies upon fermentation into the realm of biology, and nourishing a strong conviction of the identity between putrefactive changes of the body and fermentation, Pasteur was well prepared to undertake investigations which had hitherto been confined to physicians alone.

So impressed was he with the analogy between fermentation and the infectious diseases that, in 1863, he assured the French Emperor of his ambition "to arrive at the knowledge of the causes of putrid and contagious diseases." After a study upon the diseases of wines, which has had most important practical bearings, an opportunity arose which changed the whole course of his career, and profoundly influenced the development of medical science. A disease of the silkworm had, for some years, ruined one of the most important industries in France, and in 1865 the Government asked Pasteur to give up his laboratory work and teaching, and to devote his whole energies to the task of investigating it. The story of the brilliant success which followed years of application to the problem will be read with deep interest by every student of science. It was the first of his victories in the application of the experimental methods of a trained chemist to the problems of biology, and it placed his name high in the group of the most illustrious benefactors of practical industries.

In a series of studies on the diseases of beer, and on the mode of production of vinegar, he became more and more convinced that these studies on fermentation had given him the key to the nature of the infectious diseases. It is a remarkable fact that the distinguished English philosopher of the seventeenth century, the man who more than anyone else of his century appreciated the importance of the experimental method, Robert Boyle, had said that he who could discover the nature of ferments and fermentation, would be more capable than anyone else of explaining the nature of certain diseases.

In 1876 there appeared in Cohn's "Beitrage zur Morphologie der Pflanzen" (II, 277-310), a paper on the "AEtiology of Anthrax" by a German district physician in Wollstein, Robert Koch, which is memorable in our literature as the starting point of a new method of research into the causation of infectious diseases. Koch demonstrated the constant presence of germs in the blood of animals dying from the disease. Years before, those organisms had been seen by Pollender and Davaine, but the epoch-making advance of Koch was to grow those organisms in a pure culture outside the body, and to produce the disease artificially by inoculating animals with the cultures Koch is really our medical Galileo, who, by means of a new technique,—pure cultures and isolated staining,—introduced us to a new world. In 1878, followed his study on the "AEtiology of Wound Infections," in which he was able to demonstrate conclusively the association of micro-organisms with the disease. Upon those two memorable researches made by a country doctor rests the modern science of bacteriology.

The next great advance was the discovery by Pasteur of the possibility of so attenuating, or weakening, the poison that an animal inoculated had a slight attack, recovered and was then protected against the disease. More than eighty years had passed since on May 14, 1796, Jenner had vaccinated a child with cowpox and proved that a slight attack of one disease protected the body from a disease of an allied nature. An occasion equally famous in the history of medicine was a day in 1881, when Pasteur determined that a flock of sheep vaccinated with the attenuated virus of anthrax remained well, when every one of the unvaccinated infected from the same material had died. Meanwhile, from Pasteur's researches on fermentation and spontaneous generation, a transformation had been initiated in the practice of surgery, which, it is not too much to say, has proved one of the greatest boons ever conferred upon humanity. It had long been recognized that, now and again, a wound healed without the formation of pus, that is, without suppuration, but both spontaneous and operative wounds were almost invariably associated with that process; and, moreover, they frequently became putrid, as it was then called,—infected, as we should say,—the general system became involved and the patient died of blood poisoning. So common was this, particularly in old, ill-equipped hospitals, that many surgeons feared to operate, and the general mortality in all surgical cases was very high. Believing that it was from outside that the germs came which caused the decomposition of wounds, just as from the atmosphere the sugar solution got the germs which caused the fermentation, a young surgeon in Glasgow, Joseph Lister, applied the principles of Pasteur's experiments to their treatment. From Lister's original paper(*) I quote the following: "Turning now to the question how the atmosphere produces decomposition of organic substances, we find that a flood of light has been thrown upon this most important subject by the philosophic researches of M. Pasteur, who has demonstrated by thoroughly convincing evidence that it is not to its oxygen or to any of its gaseous constituents that the air owes this property, but to minute particles suspended in it, which are the germs of various low forms of life, long since revealed by the microscope, and regarded as merely accidental concomitants of putrescence, but now shown by Pasteur to be its essential cause, resolving the complex organic compounds into substances of simpler chemical constitution, just as the yeast-plant converts sugar into alcohol and carbonic acid." From these beginnings modern surgery took its rise, and the whole subject of wound infection, not only in relation to surgical diseases, but to child-bed fever, forms now one of the most brilliant chapters in the history of preventive medicine.

(*) Lancet, March 16, 1867. (Cf. Camac: Epoch-making Contributions, etc., 1909, p. 7.—Ed.)

With the new technique and experimental methods, the discovery of the specific germs of many of the more important acute infections followed each other with bewildering rapidity: typhoid fever, diphtheria, cholera, tetanus, plague, pneumonia, gonorrhoea and, most important of all, tuberculosis. It is not too much to say that the demonstration by Koch of the "bacillus tuberculosis" (1882) is, in its far-reaching results, one of the most momentous discoveries ever made.

Of almost equal value have been the researches upon the protozoan forms of animal life, as causes of disease. As early as 1873, spirilla were demonstrated in relapsing fever. Laveran proved the association of haematozoa with malaria in 1880. In the same year, Griffith Evans discovered trypanosomes in a disease of horses and cattle in India, and the same type of parasite was found in the sleeping sickness. Amoebae were demonstrated in one form of dysentery, and in other tropical diseases protozoa were discovered, so that we were really prepared for the announcement in 1905, by Schaudinn, of the discovery of a protozoan parasite in syphilis. Just fifty years had passed since Pasteur had sent in his paper on "Lactic Acid Fermentation" to the Lille Scientific Society—half a century in which more had been done to determine the true nature of disease than in all the time that had passed since Hippocrates. Celsus makes the oft-quoted remark that to determine the cause of a disease often leads to the remedy,(*) and it is the possibility of removing the cause that gives such importance to the new researches on disease.

(*) "Et causae quoque estimatio saepe morbum solvit," Celsus, Lib. I, Prefatio.—Ed.



INTERNAL SECRETIONS

ONE of the greatest contributions of the nineteenth century to scientific medicine was the discovery of the internal secretions of organs. The basic work on the subject was done by Claude Bernard, a pupil of the great Magendie, whose saying it is well to remember—"When entering a laboratory one should leave theories in the cloakroom." More than any other man of his generation, Claude Bernard appreciated the importance of experiment in practical medicine. For him the experimental physician was the physician of the future—a view well borne out by the influence his epoch-making work has had on the treatment of disease. His studies on the glycogenic functions of the liver opened the way for the modern fruitful researches on the internal secretions of the various glands. About the same time that Bernard was developing the laboratory side of the problem, Addison, a physician to Guy's Hospital, in 1855, pointed out the relation of a remarkable group of symptoms to disease of the suprarenal glands, small bodies situated above the kidneys, the importance of which had not been previously recognized. With the loss of the function of these glands by disease, the body was deprived of something formed by them which was essential to its proper working. Then, in the last third of the century, came in rapid succession the demonstration of the relations of the pancreas to diabetes, of the vital importance of the thyroid gland and of the pituitary body. Perhaps no more striking illustration of the value of experimental medicine has ever been given than that afforded by the studies upon those glands.

The thyroid body, situated in the neck and the enlargement of which is called goitre, secretes substances which pass into the blood, and which are necessary for the growth of the body in childhood, for the development of the mind and for the nutrition of the tissues of the skin. If, following an infectious disease, a child has wasting of this gland, or if, living in a certain district, it has a large goitre, normal development does not take place, and the child does not grow in mind or body and becomes what is called a cretin. More than this—if in adult life the gland is completely removed, or if it wastes, a somewhat similar condition is produced, and the patient in time loses his mental powers and becomes fat and flabby—myxedematous. It has been shown experimentally in various ways that the necessary elements of the secretion can be furnished by feeding with the gland or its extracts, and that the cretinoid or myxedematous conditions could thus be cured or prevented.

Experimental work has also demonstrated the functions of the suprarenal glands and explained the symptoms of Addison's disease, and chemists have even succeeded in making synthetically the active principle adrenalin.

There is perhaps no more fascinating story in the history of science than that of the discovery of these so-called ductless glands. Part of its special interest is due to the fact that clinicians, surgeons, experimental physiologists, pathologists and chemists have all combined in splendid teamwork to win the victory. No such miracles have ever before been wrought by physicians as those which we see in connection with the internal secretion of the thyroid gland. The myth of bringing the dead back to life has been associated with the names of many great healers since the incident of Empedocles and Pantheia, but nowadays the dead in mind and the deformed in body may be restored by the touch of the magic wand of science. The study of the interaction of these internal secretions, their influence upon development, upon mental process and upon disorders of metabolism is likely to prove in the future of a benefit scarcely less remarkable than that which we have traced in the infectious diseases.



CHEMISTRY

IT is not making too strong a statement to say that the chemistry and chemical physics of the nineteenth century have revolutionized the world. It is difficult to realize that Liebig's famous Giessen laboratory, the first to be opened to students for practical study, was founded in the year 1825. Boyle, Cavendish, Priestley, Lavoisier, Black, Dalton and others had laid a broad foundation, and Young, Frauenhofer, Rumford, Davy, Joule, Faraday, Clerk-Maxwell, Helmholtz and others built upon that and gave us the new physics and made possible our age of electricity. New technique and new methods have given a powerful stimulus to the study of the chemical changes that take place in the body, which, only a few years ago, were matters largely of speculation. "Now," in the words of Professor Lee, "we recognize that, with its living and its non-living substances inextricably intermingled, the body constitutes an intensive chemical laboratory in which there is ever occurring a vast congeries of chemical reactions; both constructive and destructive processes go on; new protoplasm takes the place of old. We can analyze the income of the body and we can analyze its output, and from these data we can learn much concerning the body's chemistry. A great improvement in the method of such work has recently been secured by the device of inclosing the person who is the subject of the experiment in a respiration calorimeter. This is an air-tight chamber, artificially supplied with a constant stream of pure air, and from which the expired air, laden with the products of respiration, is withdrawn for purposes of analysis. The subject may remain in the chamber for days, the composition of all food and all excrete being determined, and all heat that is given off being measured. Favorable conditions are thus established for an exact study of many problems of nutrition. The difficulties increase when we attempt to trace the successive steps in the corporeal pathway of molecule and atom. Yet these secrets of the vital process are also gradually being revealed. When we remember that it is in this very field of nutrition that there exist great popular ignorance and a special proneness to fad and prejudice, we realize how practically helpful are such exact studies of metabolism."(13)

(13) Frederick S. Lee, Ph.D.: Scientific Features of Modern Medicine, New York, 1911. I would like to call attention to this work of Professor Lee's as presenting all the scientific features of modern medicine in a way admirably adapted for anyone, lay or medical, who wishes to get a clear sketch of them.



CHAPTER VI — THE RISE OF PREVENTIVE MEDICINE

THE story so far has been of men and of movements—of men who have, consciously or unconsciously, initiated great movements, and of movements by which, nolens volens, the men of the time were moulded and controlled. Hippocrates, in the tractate on "Ancient Medicine," has a splendid paragraph on the attitude of mind towards the men of the past. My attention was called to it one day in the Roman Forum by Commendatore Boni, who quoted it as one of the great sayings of antiquity. Here it is: "But on that account, I say, we ought not to reject the ancient Art, as if it were not, and had not been properly founded, because it did not attain accuracy in all things, but rather, since it is capable of reaching to the greatest exactitude by reasoning, to receive it and admire its discoveries, made from a state of great ignorance, and as having been well and properly made, and not from chance."(1)

(1) The Works of Hippocrates, Adams, Vol. I, p. 168, London, 1849 (Sydenham Society).

I have tried to tell you what the best of these men in successive ages knew, to show you their point of outlook on the things that interest us. To understand the old writers one must see as they saw, feel as they felt, believe as they believed—and this is hard, indeed impossible! We may get near them by asking the Spirit of the Age in which they lived to enter in and dwell with us, but it does not always come. Literary criticism is not literary history—we have no use here for the former, but to analyze his writings is to get as far as we can behind the doors of a man's mind, to know and appraise his knowledge, not from our standpoint, but from that of his contemporaries, his predecessors and his immediate successors. Each generation has its own problems to face, looks at truth from a special focus and does not see quite the same outlines as any other. For example, men of the present generation grow up under influences very different from those which surrounded my generation in the seventies of the last century, when Virchow and his great contemporaries laid the sure and deep foundations of modern pathology. Which of you now knows the "Cellular Pathology" as we did? To many of you it is a closed book,—to many more Virchow may be thought a spent force. But no, he has only taken his place in a great galaxy. We do not forget the magnitude of his labors, but a new generation has new problems—his message was not for you—but that medicine today runs in larger moulds and turns out finer castings is due to his life and work. It is one of the values of lectures on the history of medicine to keep alive the good influences of great men even after their positive teaching is antiquated. Let no man be so foolish as to think that he has exhausted any subject for his generation. Virchow was not happy when he saw the young men pour into the old bottle of cellular pathology the new wine of bacteriology. Lister could never understand how aseptic surgery arose out of his work. Ehrlich would not recognize his epoch-making views on immunity when this generation has finished with them. I believe it was Hegel who said that progress is a series of negations—the denial today of what was accepted yesterday, the contradiction by each generation of some part at least of the philosophy of the last; but all is not lost, the germ plasm remains, a nucleus of truth to be fertilized by men often ignorant even of the body from which it has come. Knowledge evolves, but in such a way that its possessors are never in sure possession. "It is because science is sure of nothing that it is always advancing" (Duclaux).

History is the biography of the mind of man, and its educational value is in direct proportion to the completeness of our study of the individuals through whom this mind has been manifested. I have tried to take you back to the beginnings of science, and to trace its gradual development, which is conditioned by three laws. In the first place, like a living organism, truth grows, and its gradual evolution may be traced from the tiny germ to the mature product. Never springing, Minerva-like, to full stature at once, truth may suffer all the hazards incident to generation and gestation. Much of history is a record of the mishaps of truths which have struggled to the birth, only to die or else to wither in premature decay. Or the germ may be dormant for centuries, awaiting the fullness of time.

Secondly, all scientific truth is conditioned by the state of knowledge at the time of its announcement. Thus, at the beginning of the seventeenth century, the science of optics and mechanical appliances had not made possible (so far as the human mind was concerned) the existence of blood capillaries and blood corpuscles. Jenner could not have added to his "Inquiry" a study on immunity; Sir William Perkin and the chemists made Koch technique possible; Pasteur gave the conditions that produced Lister; Davy and others furnished the preliminaries necessary for anaesthesia. Everywhere we find this filiation, one event following the other in orderly sequence—"Mind begets mind," as Harvey (De Generatione) says; "opinion is the source of opinion. Democritus with his atoms, and Eudoxus with his chief good which he placed in pleasure, impregnated Epicurus; the four elements of Empedocles, Aristotle; the doctrines of the ancient Thebans, Pythagoras and Plato; geometry, Euclid."(2)

(2) Works of William Harvey, translated by Robert Willis, London, 1847, p. 532.

And, thirdly, to scientific truth alone may the homo mensura principle be applied, since of all mental treasures of the race it alone compels general acquiescence. That this general acquiescence, this aspect of certainty, is not reached per saltum, but is of slow, often of difficult growth,—marked by failures and frailties, but crowned at last with an acceptance accorded to no other product of mental activity,—is illustrated by every important discovery from Copernicus to Darwin.

The difficulty is to get men to the thinking level which compels the application of scientific truths. Protagoras, that "mighty-wise man," as Socrates called him, who was responsible for the aphorism that man is the measure of all things, would have been the first to recognize the folly of this standard for the people at large. But we have gradually reached a stage in which knowledge is translated into action, made helpful for suffering humanity, just as the great discoveries in physics and chemistry have been made useful in the advance of civilization. We have traced medicine through a series of upward steps—a primitive stage, in which it emerged from magic and religion into an empirical art, as seen among the Egyptians and Babylonians; a stage in which the natural character of disease was recognized and the importance of its study as a phenomenon of nature was announced; a stage in which the structure and functions of the human body were worked out; a stage in which the clinical and anatomical features of disease were determined; a stage in which the causes of disorders were profitably studied, and a final stage, into which we have just entered, the application of the knowledge for their prevention. Science has completely changed man's attitude towards disease.

Take a recent concrete illustration. A couple of years ago in Philadelphia and in some other parts of the United States, a very peculiar disease appeared, characterized by a rash upon the skin and moderate fever, and a constitutional disturbance proportionate to the extent and severity of the eruption. The malady first broke out in the members of a crew of a private yacht; then in the crews of other boats, and among persons living in the boarding-houses along the docks. It was the cause of a great deal of suffering and disability.

There were three courses open: to accept the disease as a visitation of God, a chastening affliction sent from above, and to call to aid the spiritual arm of the church. Except the "Peculiar People" few now take this view or adopt this practice. The Christian Scientist would probably deny the existence of the rash and of the fever, refuse to recognize the itching and get himself into harmony with the Infinite. Thirdly, the method of experimental medicine.

First, the conditions were studied under which the individual cases occurred. The only common factor seemed to be certain straw mattresses manufactured by four different firms, all of which obtained the straw from the same source.