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Popular Science Monthly/Volume 80/May 1912/Research in Medicine I

RESEARCH IN MEDICINE[1]
By Professor RICHARD M. PEARCE

UNIVERSITY OF PENNSYLVANIA

I. Antiquity to 1800; The Efforts of Isolated Investigators

THE phrase "Research in Medicine" will naturally arouse different thoughts and associations in the minds of different groups of men.

The bacteriologist will be reminded of Pasteur, Koch, Behring and Flexner and the triumphs of bacteriology and serum-therapy; the surgeon, of Lister and antisepsis, of anesthesia, and of the X-ray; the physician of new means of cure and of diagnosis, of specific sera and vaccines, of the electrocardiograph, the polygraph and other complicated instruments of precision; and the average layman of a confused and confusing welter of catchwords and slogans for popular agitations vaguely associated with antitoxins, mosquitoes, good water supply, sewage disposal, lowered infant mortality and the modern treatment of tuberculosis. But in the last analysis the impressions of all would be of progress in a period representing a little more than half of the past century. This period is indeed the golden age of medical progress and one to which the historian or philosopher must give his best attention if he is to interpret, properly, the impulses which actuate medical research at the present time. That the earlier history of medicine is overshadowed by the rapid progress of modern discovery as represented in bacteriology is in the nature of things. But it should not, for that reason, be forgotten that the art of medicine existed before this period and with it much science. The pathologist, on second thought, reminds us of Morgagni and Rokitansky and the beginnings of pathological anatomy; the physiologist recalls Harvey and Haller; the surgeon mentions Ambroise Paré; the anatomist, after recalling many worthies, takes us back to Vesalius, to Galen and finally leaves us as does the internist, with Hippocrates, 400 years before Christ.

With this stretch of time and with these widely varying aspects of endeavor one must deal in attempting to present the story of research in medicine. It would be comparatively simple to chronicle the advance in any one field, as, for example, surgery, pathology or therapy; but this would, I fear, be less interesting and certainly not enlightening as to the full influence of research. The advantages to the community resulting from research in medicine are advantages because re"search has done away with conditions which were disadvantageous to the health, the happiness and prosperity of the community—in short such research has removed the impediments to a higher, happier and more prosperous civilization. It is necessary, therefore, in order to emphasize the importance of what has been accomplished, to portray the conditions of community life and individual hygiene, of medical practise and medical thought, and of science and philosophy at such periods as immediately precede definite advances in medical knowledge. The first of these lectures, then, bringing the story down to the beginning of the nineteenth century, will be presented from this point of view. The second lecture devoted to the influence of physics and chemistry, and the third to the rise of bacteriology, will outline the development of laboratory methods of investigation, the story, essentially, of medicine in the last half of the nineteenth century. The fourth lecture will be a survey of present-day methods and problems, and the fifth lecture will be a discussion of the position of medical research in America, its facilities, needs and opportunities, with special reference to medical research as a function of the university.

Of medicine in the earliest stages of its development we have no knowledge. Not until we arrive at a period of civilization as highly developed as that of the Assyrians and Egyptians do we find references to the practise—the studied practise—of medicine as a healing art. For all that precedes that period we must rely on analogy with medical practises among the aboriginal races to-day. But we can, nevertheless, safely assume that the healing art in all times, no matter how simple its form, was the practise of methods having for their object the relief of pain or the repair of injuries caused by mechanical means. Such methods must have been, at first, instinctive and empiric, or the result of chance observation. Some may, indeed, have been analogous to the methods which an animal adopts to cleanse a wound or protect an injured limb. The use of irritants, of emollients and of scarification, the binding of wounds, the mechanical support of a fracture and assistance in childbirth are primitive practises doubtless resulting from chance observation or experience. It is readily conceivable that the use of stone tools and weapons in hunting and in war may have originated the idea of intervention by operation; and that surgical dexterity may have increased proportionately to the improvement of weapons in the bronze age. Likewise it must be assumed that chance experience led to a knowledge of the action of the vegetable and mineral substances of the early materia medica. But of these beginnings we have no historical knowledge.

Our first authentic knowledge of medicine, fragmentary though it is, is obtained from the cuneiform inscriptions which record the Babylonic-Assyrian civilization. These records are of a medicine controlled by the priesthood, closely linked to astrology and characterized by a belief in the influence of metaphysical forces, gods and demons. They do, however, contain references to the use of the knife in surgery, the healing of fractures and the internal administration of herbs, but all essential therapy is obscured by mysticism, ritual observances and magical formula. From the point of view of diagnosis, it is of interest that these records refer to the inspection of the urine and blood and to the collection of a series of observations upon disease, what we would now call the "clinical history" or record of a patient. These, however, were taken, not as to-day to aid in the diagnosis, but had the value of omens to aid the priest in his prophecy as to the outcome of the illness, or as we would say to aid prognosis. Such records were of little value, for without a knowledge of pathology—that is, of the underlying anatomical changes responsible for the symptoms—they were on the same level as astrological speculation and the interpretation of dreams. Inferences were not drawn from the empirical facts of clinical observations, but all observations were interpreted in the light of the supernatural, the ritualistic and the magical. This veil we find over all ancient medicine.

Egyptian medicine of a period 2,000 B.C. was much the same as the Assyrian, but the priestly science, as taught in the schools of the temples, developed a considerable knowledge of botany and zoology, without, however, an insight into the structure and functions of the human body. An extensive materia medica allowed the use of medicines as draughts, electuaries, gargles, snuffs, inhalations, salves, plasters, poultices, injections, suppositories, enemata and fumigations. As to general surgery, there is no evidence, aside from circumcision and castration, of operations other than those for the removal of surface tumors. Yet ophthalmology, otology and dentistry were known and practised as specialties. Obstetrics, on the other hand, does not appear to have been of interest to the physician. The hygiene of the Egyptians ranked higher than their therapeutics and included definite rules concerning meat inspection, bathing, clothing, diet, care of the dwelling and of infants. Indeed there is much ground for the belief that much of our modern hygiene can be traced back through Greek and Hebrew to the pioneer work of the ancient Egyptians.

Persian medicine is of little moment and differs but slightly from that of other ancient peoples in its religious-hygienic measures. One phase of religious belief was disastrous for the development of even simple empiricism—the belief that the dead and the diseased were unclean. Such a view naturally made impossible the study of anatomy and diagnosis. The sick, as unclean, were isolated, washed and purified —a procedure which in our time we associate with good hygiene and the care of those suffering with contagious diseases; with the Persians, however, it was purely a religious form based on a belief in demons.

After the priestly hygiene of the Egyptians and Persians comes naturally, and probably sequentially, the social hygiene of the Old Testament. I need only remind you of the Mosaic laws, rational even in the light of modern science.

From the literature of antiquity much else might be cited to show the state of medicine among ancient peoples, the influence of religion, of primitive superstition and mysticism, all of which, however well-intentioned, prevented or obscured exact observation and deduction. The development of knowledge by observation and critical argument came slowly, and was possible only when the priest was no longer the physician. This great advance we associate with the period of Greek civilization and the name of Hippocrates.

Hippocrates may be considered in many ways, as physician, surgeon, philosopher and medical historian, but to one interested in the beginnings of research in medicine he is of importance as the first to record results based on observation, experiment and deduction, the tripod of the method of science. As a result, although much of his theory has been discarded, many of his procedures based on exact observation still stand the test of time and in many instances form the basis of modern methods. His age (470-361 B.C.) was the age of Pericles; contemporary with him, Thucydides wrote history, Phidias carved statues, Democritus originated his atomistic theory of the universe, and Socrates talked "human affairs" and "practical reason." That these men were real to one another is shown by the fact that Hippocrates was requested to declare Democritus insane and that Pericles died (429 B.C.) of the great plague which Hippocrates attempted to combat.

From this correlation of names it is evident that medicine shared in the general growth of Greek culture, and there is every evidence that Hippocrates was as great a representative of Greek intellect as were his contemporaries. Greece was at the height of its brilliant progress; it was, for the time being, the political, commercial, intellectual, scientific and artistic center of the universe. But among the Greek? the priests were not, fortunately for medicine, political or intellectual leaders; leadership was possessed first by the poets and later by the philosophers, and, under such circumstances, Greek medicine, freed of religious influence and fostered by philosophy, took a substantial form, and, though it contained much of generalized speculation, it had the solid foundation of unbiased observation. The former has perished under the influence of time and progress; the latter, resting on actual experience and genuine biological knowledge, remains. Of the methods of Hippocrates some idea may be obtained from the fact that he is responsible for the very term "hypothesis," which, in its scientific application, he invented.

Some of the experiments of the Hippocratic schools may be considered as the first in the field of experimental physiology, as for example, the feeding at the same time of different kinds of food and the study, after induced vomiting, of the stage of digestion of each. It is, however, in the field of clinical observation that Hippocrates excelled. His inferences were frequently wrong, but his descriptions of the symptoms of a disease, as an aid to diagnosis and prognosis, were at once picturesque and accurate. How accurate and vivid they were may be seen from the fact that the characteristic signs of impending death are still known as the "facies Hippocrates." This exercise of minute observation and accurate interpretation of every symptom—the method of clinical medicine—which has influenced medicine in all succeeding ages, was the beginning of the study of what we now term the "natural history of disease." In therapy Hippocrates recognized the natural tendency to health (vis medicatrix naturæ) and this principle influenced all his therapeutic efforts. In addition to this substantial service to medicine we owe him certain idealistic influences as shown in the Hippocratic oath and in his constant desire to place all knowledge freely and fully before the profession at large.

Certainly medicine under Hippocrates, as contrasted with that of the preceding ages, was magnificent, and it is not surprising that after his death, he was deified. To us he represents the beginnings of an exact medicine, and his influence is seen in many of the theories, methods and ideals of modern practise. Hippocratic medicine, Hippocratic doctrine, Hippocratic oath, are current phrases, and the admonition "Back to Hippocrates" is an admonition to beware of theory and seek the solid ground of observation and experiment.

Between Hippocrates and Galen lie nearly five hundred years without progress in medicine, except as the brilliant Alexandrian school, sheltering Euclid, Archimedes and Ptolemy developed, under Herophilus and Erasistratus, a school of anatomy (ca. 300 B.C.) which established many new anatomical facts. But as Neuburger states in his discussion of early medical theories, "Collection and observation of facts constitute the first step in science, but not science itself." The observation of anatomical facts during these centuries is naturally of some importance in connection with the growth of anatomy, but unfortunately of no importance as regards the influence of those facts on medical theory, for physiology remained a field for speculation while the facts gained from anatomy were used only to strengthen the older speculation and dogmatism, and to rehabilitate discarded doctrines. To the Alexandrian school and to Galen, however, must be given the -credit of a careful study of anatomy by dissection, and this honor is the more deserved because, from Galen to Vesalius—a stretch of nearly fourteen hundred years—knowledge of anatomy was not advanced.

Galen (131-201 A.D.), a Greek, working in Rome, followed the traditions of the Alexandrian school in which he had been educated. He dissected freely a variety of animals, including, it is recorded, an elephant. It is, however, as an experimental physiologist that he brought new light to medicine. He supported the statements of the Alexandrian school, that nerves had motor and sensory functions, elaborated the theory of the control of muscles by nerves, and of the brain as the center of the nervous system, and, more important still, supported these convictions by well-planned ingenious experiments. His experiments on the brain and cord constitute the first experimental study of the cause of paralysis, and he thereby became cognizant of the fact that injury to one side of the brain affects the opposite side of the body. He established, again by experiment, that urine is secreted by the kidneys, and propounded the theory that the blood goes to the kidneys in order that the watery part may be filtered off. He studied the heart and its movements, recognized the fetal nature of the foramen ovale and the ductus arteriosus, wrote of aneurysm and practised the ligation of arteries.

Galen is the link between Hippocrates and Alexandrian anatomy, on the one hand, and Vesalius and Harvey, on the other.

With his death and the passing of his immediate successors progress languished and expired, for the ancient world was dying and was bearing down with it the humaner arts. . . . For generations it seemed that the church alone had survived. . . cherishing ignorantly often, but jealously and fiercely, the records of a past science. (Mumford.)

The intellectual world of Rome, Alexandria and Constantinople was busied with theological controversies. The church became the arbiter of all knowledge and demanded that all science must conform to the Scriptures. Moral and intellectual progress became impossible. The political world survived the invasion of the barbarians, but the intellectual world was dying of dogma. For hundreds of years it was "first the soldier; second the priest; third the lawyer; fourth the merchant; fifth the physician; and then after a long interval the surgeon, ranking with the humblest of craftsmen." (Mumford.)

Nearly fourteen centuries pass after Galen before we can again take up the thread of progress. In these centuries—lost to science generally—the history of medicine shows but one isolated period of effort worthy of mention. This is that period represented by the Arabian school founded after the Mahommedan conquest and at its best from the ninth to twelfth centuries. This school represents no progress in anatomy, physiology or the general theory of medicine (which is to be explained by the fact that the religion of the Mussulman considers contact with a corpse sacrilege and thus debars dissection), but the Arabs had an insight into chemistry, and, though they pursued their researches in the interests of alchemy and in the hope of finding the "elixir of life" or means of transmuting metals, they made, nevertheless, valuable chemical discoveries and in this way aided the art of pharmacy.

We therefore enter the sixteenth century of the christian era with little or nothing added during 2,000 years to Hippocrates's methods of exact observation in clinical medicine and surgery, with no decisive contribution to anatomy or experimental physiology for 1,300 years and with the beginnings of chemistry as applied to medicine and pharmacy removed by 600 years.

But despite this absence of real progress, a thin thread of learning and practise connected the medicine of Galen with the dawn of science in the middle ages. This is evident in the story of medicine in the monasteries and in the schools at Salerno and Montpellier in the twelfth century, but it is a medicine of the Roman period tinctured with magic and superstition and with no advance in theory or practise and certainly no increase in science.

The medicine associated with the revival of learning had its beginnings in the translation of Greek treatises on medicine through the Arabic; and in the early universities, especially those of Padua and Bologna and this revival of the exact methods of Hippocrates and Galen, gave to medicine a basis more substantial than the traditions of monastic medicine which had been perpetuated through ten centuries, and upon which were founded those widely scattered, but epoch-making advances which medicine reckons as its share in the general revival of literature, art and the sciences. With the name of Luther, Michael Angelo, Raphael, Titian, Copernicus, Columbus and Galileo we place those of Vesalius, Paré and Harvey. These names represent the period of the Renaissance, to which we look back with pride and satisfaction, but seldom with a thought of the conditions of home and community life. We are concerned usually with its deeds and achievements rather than with its social and hygiene conditions. But it is to the latter that I wish here briefly to direct attention.

The homes and habits of the people were filthy. As late as the sixteenth century in England, the streets of the populous cities were paved with straw and rushes, which soon broke up into powdered dust. Householders swept the filth of their apartments into the streets, and threw garbage there also, where, with the ground of rush and straw, a most intolerably filthy condition was produced, which rain modified, but did not remove. Moreover, people seldom bathed their bodies or washed their clothes. Besides, the food they ate contributed to disease. They lived chiefly on salt fish and flesh, with a modicum of stale vegetables. The domestic animals, the source of their meat, were herded in enclosures of the worst imaginable filth. Mutton was the chief flesh food of the people, but their flocks in cold season were herded in basements, partly underground, places without light and air except such as gained admittance from the door. Milch cows were confined to these places also. The source of the food supply was, therefore, foul. . . . Places of public resort were without means of ventilation. The air of the churches was death-dealing, and made tolerable only by the fumes of incense. (Gorton.) Personal cleanliness was unknown; great officers of state, even dignitaries as high as the Archbishop of Canterbury, swarmed with vermin; such it is related was the condition of Thomas a' Becket, the antagonist of an English king. To conceal personal impurity, perfumes were necessarily and profusely used. The citizen clothed himself in leather, a garment, which, with its ever-accumulating impurity, might last for many years. . . . After night-fall the chamber shutters were thrown open, and slops unceremoniously emptied down. (Draper.)[2]

From the fourteenth to the sixteenth century plagues were frequent and attended with great mortality. Among the plagues known by various names as the "sweating sickness," "black death," etc., we are able to distinguish bubonic plague, typhus and small-pox. Likewise syphilis had been on the increase since the fifteenth century, and presented a peculiar malignancy, and, like small-pox, attacked high and low alike. The causes and origin of these plagues are not difficult to find. Except for the Cloaca Maxima at Rome not a sewer of any consequence existed in Europe; drainage was inadequate, the streets were unpaved, and public baths or other facilities for bathing were unknown. Of sanitation no knowledge was at hand. The dead, including the victims of various plagues, were buried hastily—instead of being burned—and usually in shallow ditches, thus allowing presumably an easy pollution of water supplies. As to this, under ordinary circumstances no precautions were taken to keep the water supplies free from fecal and other contaminations. Doubtless, taxes on bread and window panes were responsible in no small part for that diminished resistance which invites infection. Against the spread of plagues the physicians were helpless. The College of Physicians at Paris in the fifteenth century at the time of the "sweating plague," were, after mature consideration, "of the opinion, that the constellations, with the aid of nature, strive, by virtue of their divine might, to protect and heal the human race." This state of mind does not seem so surprising when we recall that Roger Bacon, "the truest philosopher of the Middle Ages," still sought, in the thirteenth century, the philosopher's stone and the elixir of life. "The Royal Touch" was still a favorite cure for scrofula ("The Kings of Evil") and various other ills, and indeed persisted into the time of Queen Elizabeth. From "The Anatomy of Melancholy" (1621) we have it that "there be many mountebanks, quacksalves and empiricks, in every street almost, and in every village."

Shall we, then, wonder that, in the famine of 1030, human flesh was cooked and sold; or that, in that of 1258, fifteen thousand persons died of hunger in London? Shall we wonder that, in some of the invasions of the plague, the deaths were so frightfully numerous that the living could hardly bury the dead? By that of 1348, which came from the east along the lines of commercial travel and spread all over Europe, one third of the population of France was destroyed. (Draper.)

Also, the condition of the insane was pitiable; until well into the eighteenth century they were imprisoned, chained and treated as wild beasts.

Rational therapy did not exist, though it is interesting to note that several important empiric specifics came gradually into general use, as mercury and sulphur introduced in 1510 by Paracelsus, sometimes termed "charlatan and bombast"; after Harvey's time, Dover's powder (Pulvis Ipecacuanæ Comp.) through Captain Dover, physician and buccaneer; and Cinchona (quinine) through the Countess of Cinchon, wife of the Viceroy of Peru, who brought it to the attention (1638) of the Jesuit priests, hence the name, Jesuit's bark. Truly, empirical therapy made progress by curious routes.

Civil surgery was in a chaotic state, the barber surgeon contended with the surgeon proper or "surgeon of the long robe" in the fields of minor surgery and both ranked far below the physician. In fact, surgery was largely abandoned to a class of ignorant barbers, bathers and bone-setters. Many operators were itinerant, going from city to city and frequently limiting their work to one or two kinds of operation, as that for cataract, or stone, or hernia. Military surgery without anesthesia or antisepsis was a horror of rough and ready emergency operations with boiling oil or heated iron as styptic and cautery, a torture beyond imagination. Indeed, to get an idea of the horrors of surgery in the lazaretto of the battle field even down to the year 1812, the date of Napoleon's descent upon Moscow, one needs but to read Tolstoy's work "War and Peace."

Thus we find the stage set for Vesalius and Paré, who with Hunter, though he entered somewhat later, laid the foundation, which, when anesthesia and antisepsis were added in the nineteenth century, gave surgery its right to claim a scientific basis. Vesalius, occupying a chair of surgery at Padua, developed anatomy as an exact observational science; indeed he may be considered as the founder of modern anatomical research. This was his great work; this and his influence in weakening the old speculative medicine and in establishing the principles of the scientific method. It was not an immediate influence, for upon the publication (1543) of his Pabrica Humani Corporis "the wrath of intrenched conservatism descended upon him" and he was forced to leave Padua, but his work was not in vain, for it hastened the development of surgical science and gave to anatomy the impetus necessary for its development as an observational science.

Ambroise Paré (1510-1590) began life as an humble barber-surgeon, and ended as the greatest surgical authority of Europe and the best loved man in* France. (Mumford.)

Why the greatest authority? Because he went through the world with his eyes open. Why the best beloved? Because of his own unaided efforts he did away with more actual pain than has perhaps any other single individual except the discoverer of anesthesia. His methods were those of the practical clinician—observation as the basis of deduction unhampered by tradition. The story is told that Paré in his first military campaign followed the old custom which prescribed the use of boiling oil for all wounds. But after one severe engagement the oil gave out and he used, fearful of the consequences, a simple ointment. To his surprise he found that the wounds so treated healed more rapidly than under the old treatment. On this basis of simple observation and sound reasoning, he combated, against great opposition, the old treatment and established simple rules for the care of wounds. So also was it with the ligation of vessels after amputation. The custom had been to cauterize with the red-hot iron, the effect of which both physically and mentally it is not difficult to imagine. Paré reasoned that as ligation of veins and arteries in simple wounds was possible, it was possible also at amputation, and at the first opportunity he demonstrated the correctness of his views. So by doing away with boiling oil and the heated iron he ranks among the greatest of humanitarians and, by establishing rational procedures for the treatment of wounds and for the ligation of vessels, as one of the greatest of surgeons.

Here it is well to depart from the chronological order and discuss John Hunter and his work and thus bring the advance in surgery to the year 1800. Between Paré and Hunter surgery was influenced by Haller and Harvey, but both these must be treated in detail in a consideration of other lines of activity. Suffice it to point out here that Harvey's work on the circulation of the blood and Malpighi's discovery of capillary circulation advanced surgery enormously by clearing up for the surgeon the mysteries of the blood-vascular system. The dread of hemorrhage had previously deterred surgeons from all operations except those of dire necessity or those in which the operation was in a gangrenous tissue. With this mystery of hemorrhage solved, the surgeon boldly ventured into new territory and rapidly extended the possibilities of his art.

John Hunter, pathologist, physiologist and surgeon, was active in the latter part of the eighteenth century. He worked in anatomy, comparative anatomy, physiology and surgery; essentially a laboratory investigator, "content" it is said "with four hours of sleep, scanty rations and little play." (Mumford.) Many were his contributions to anatomy, but his work on coagulation of the blood, inflammation and the repair of wounds, and, above all, the demonstration, that after ligation of vessels there occurs the establishment of a collateral circulation by anastomosis, were of the utmost importance to surgery. This latter, the basis of his famous operation for aneurism, was the result of a study of the growth of deer's antlers, in the course of which he tied one of the carotid arteries. To his surprise the cold antler of the ligated side, after two weeks, became warm. Dissection demonstrated that the ligature had not slipped, and on the basis of this observation he established those principles concerning the ligation of vessels in continuity so important in modern surgery. He also presented the first satisfactory explanation of inflammatory and thrombotic diseases of veins and contributed to the knowledge of gunshot wounds and of many other phases of medical science; but his great influence was the impetus which he gave to proper scientific research in medicine as well as surgery, in pathology as well as physiology.

To Hunter, the nineteenth century English school of surgery owes its fame, and in his honor the Royal College of Surgeons established the annual Hunterian Oration. After Hunter, and largely due to his influence, surgery advanced surely, though slowly, but without momentous discoveries until the advent of anesthesia and asepsis in the middle of the nineteenth century. We may therefore leave surgery and turn to Harvey and events in physiology prior to 1800.

Harvey was of the Elizabethan period, a contemporary of Shakespeare, Milton, Dryden, Bacon, Descartes and Kepler. He studied at Cambridge and Padua and on his return to England, as Lumleian lecturer, gave most of his time to teaching and dissection. It was during the second year (1616) of such labors that he first propounded his theory of the circulation of the blood, but it was not until 1628 that his complete work on the subject was published. With the discussion as to the part played by his forerunners, by Servetus, Cæsalpinum and others in elucidating the mysteries of the circulation we are not now concerned. The honor of the establishment of the theory is Harvey's. More than this, it was the character of his exhaustive observations on a score of different animals (and on the heart of the chicken in ovo), his logical reasoning, and his convincing experiments that finally led to the correct solution and to the resurrection of a new method in medicine, that of experimental physiology. It may be remembered that Galen has been referred to as the first experimental physiologist; after fourteen hundred years he was followed by Harvey; then came Haller and Hunter, prophets of that modern experimental physiology which was in the nineteenth century to advance along all lines and to give to medicine a scientific foundation.

It is difficult to overestimate the significance of Harvey's discovery of the circulation of the blood. Sir Thomas Brown considered it greater than Columbus's discovery of America; Hunter ranked it with that of Columbus and that of Copernicus. Certainly it opened a new world in medicine. Progress, however, did not immediately follow Harvey's discovery, though four years after his death the capillary system, a link necessary to the completion of his doctrine of the circulation, was discovered by Malpighi. The period, was, however, one of detailed observation in anatomy, and despite the work of Malpighi and Borelli, experimental physiology languished until the time of Haller (1708-1777), who made additions to the knowledge of the mechanics of respiration, established the theory of irritability as a specific property of muscle and made important observations in embryology. How prophetic of the advances of the nineteenth century are the problems with which Haller and Hunter busied themselves. The study of the irritability of muscle suggests physiological instruments of precision, and embryology implies the compound microscope and the microtome, the familiar instruments of the latter nineteenth-century investigator in medicine. Hunter's problems—phlebitis, aneurism, syphilis, inflammation, the repair of wounds, the coagulation of the blood—remind one of many phases of present-day investigation. Prophetic also of the phenomenal development of pathology, under Rokitansky and Virchow, was Morgagni's publication in 1761 of his "Seats and Causes of Disease," the first systematic effort to correlate clinical manifestations with pathological anatomy. Likewise, the introduction by Jenner (1796) of the systematic practise of vaccination against small-pox, presaged those methods of prophylaxis which within the next century were to revolutionize the methods of controlling many of the infectious diseases. We will return in later lectures to both Morgagni and Jenner and their influence on the development of pathology and immunology, but here they serve with Hunter and Haller to illustrate how a few individuals with a genius for accurate observation, sound thinking and exact experimentation may by their contributions foreshadow the activities of a succeeding century, and be the forerunners of new schools of thought. Their labors with those of Vesalius, Paré and Harvey are examples of that effort which, isolated though it was, during the three or four centuries preceding the year 1800 and proceeding as it did from individuals living and working in widely separated places, nevertheless, constituted in the sum a sound body of knowledge readily available to future investigators, equipped with new methods. With the exception of Paré no one of these men was' thoroughly appreciated by his contemporaries. Vesalius was reviled and forced to leave Padua, Hunter's ligation of a vessel in continuity was at first ridiculed and Harvey's discovery, like others in various fields, because not possible at once of practical application, did not appeal to medical men-who still clung to the traditional teachings of Galen. It was the period of genius working alone without the approval of the profession, without the support of universities and laboratories, and without the means of publications and the means of travel that to-day render almost immediately available new advances, achievements and theories. One had to journey to the city or country of this or that authority or investigator to get his views. Merz, in his "History of European Thought in the Nineteenth Century," gives, as examples of such voyages of discovery Voltaire's visit "to England in 1728, where he found the philosophy of Newton and Locke, at that time not known and therefore not properly appreciated in France; the journey of Adam Smith in 1765 to France, where he became acquainted with the economic system of Quesnay"; and the visit of Wordsworth and Coleridge to Germany, whence the latter brought to England the new philosophy of Kant and Schelling." It is not surprising that under such circumstances advances in medicine, as in science generally, were few and far between.

How the change from individual to organized effort came about, and how medicine became the subject of investigation by scientific methods in laboratories established for that purpose will be shown in the next lecture.

  1. These lectures were given as the annual Hitchcock lectures at the University of California. The foundation was created by Mr. Charles M. Hitchcock, who bequeathed to the University of California an endowment, the income of which was to be devoted to "free lectures upon scientific and practical subjects, but not for the advantage of any religious sect nor upon political subjects."
  2. The original upon which these statements are based I have been unable to obtain. Gorton's statement is evidently at second hand. C. Creighton in his "History of Epidemics in Great Britain" doubts the accuracy of the sweeping charges "of neglect of public hygiene" and "of lack of rudimentary instincts of cleanliness" in Plantagenet and Tudor times, but as careful a writer as F. Harrison gives in "The Meaning of History" the following summary of personal and community hygiene in the Middle Ages: "The old Greek and Roman religion of external cleanness was turned into a sin. The outward and visible sign of sanctity now was to be unclean. No one was clean; but the devout Christian was unutterably foul. The tone of the Middle Ages in the matter of dirt was a form of mental disease. Cooped up in castles and walled cities, with narrow courts and sunless alleys, they would pass day and night in the same clothes, within the same airless, gloomy, windowless and pestiferous chambers; they would go to bed without night clothes, and sleep under uncleansed sheep-skins and frieze rugs; they would wear the same leather,^ fur and woolen garments for a lifetime, and even for successive generations; they ate their meals without forks, and covered up the orts with rushes; they flung their refuse out of the window into the street or piled it up in the back-yard; the streets were narrow, unpaved, crooked lanes through which, under the very palace turrets, men and beasts tramped knee-deep in noisome mire. This was at intervals varied with fetid rivulets and open cesspools; every church was crammed with rotting corpses and surrounded with graveyards, sodden with cadaveric liquids, and strewn with disinterred bones. Bound these charnel houses and pestiferous churches were piled old decaying wooden houses, their sole air being these deadly exhalations, and their sole water supply being these polluted streams or wells dug in this reeking soil. Even in the palaces and castles of the rich the same bestial habits prevailed. Prisoners rotted in noisome dungeons under the banqueting hall; corpses were buried under the floor of the private chapel; scores of soldiers and attendants slept in gangs for months together in the same hall or guard-room where they ate and drank, played and fought. It is one of those problems which still remain for historians to solve—how the race ever survived the insanitary conditions of the Middle Ages, and still more how it was ever continued—what was the normal death-rate and the normal birth-rate of cities? The towns were no doubt maintained by immigration, and the rural labourer had the best chance of life, if he could manage to escape death by violence or famine."