Invisible is a complex of equal size, consisting of all the buildings that have been erected and then torn down during the last hundred and forty-six years-the isolation wards, the Building for Offensive Diseases, the laboratories and operating rooms that have come and gone as the demands of medical practice and the patterns of disease have shifted.

The hospital is now so large and so busy that it is difficult to grasp the magnitude of its activity. In 1961, it admitted 27,000 patients, performed 16,000 operations, treated 62,000 people in its emergency ward, examined 115,000 patients by X ray, saw 226,000 clinic patients, and dispensed 176,000 prescriptions from its pharmacy. These figures are so large as to be almost meaningless. A better way to look at the job the hospital does is to view it on the basis of a twenty-four-hour day, three hundred sixty-five days a year. On that basis, the hospital sees a new patient in the emergency ward every eight minutes. X rays are taken on a patient every five minutes. A new patient is admitted every twenty minutes. And a new operation is begun every thirty minutes.

The hospital's operating budget is some $35 million yearly. It has grown so expensive, in fact, that the initial sum of $140,000 that was used to build the hospital in 1821 now could not support its operation for a day and a half.

The growth in patient care has been equaled by a growth in teaching activity. From a handful of medical students following a senior man from patient to patient in 1821, the hospital's student population has grown to more than 800, including 250 medical students, 304 interns and residents, and 339 nursing students.

Added to these two traditional concerns- patient care and teaching-has been a third purpose: research. Here the growth has been both recent and phenomenal. As late as 1935, the MGH research budget was $44,000. By 1967, it was $10.5 million, with another $1.3 million for indirect costs of research. The research activities have transformed the very nature of the institution, making it, in combination with the medical school, a complete system for medical advance. Discoveries are made here; they are applied to patients; and new generations of physicians are trained in the new techniques.

It is this orientation toward innovation, and this commitment to scientific advancement, that the teaching hospital has contributed to the long history of hospitals. In other areas of its development, such as the emphasis on emergency care, the teaching hospital shares a trend evident among all hospitals everywhere, though it displays the trend in a more pronounced form.

The evolution of the hospital has been going on for more than two thousand years, beginning with the first system of hospitals about which much is known, the aesculapia of Greece. These first appeared around 350 b.c., taking the form of temples to Aesculapius, a deified physician who had lived nearly a thousand years earlier. (Homer insists that Aesculapius was a mortal, despite the fact that he was a pupil of the centaur Chiron.) The legendary fate of Aesculapius is ironic, for it represents the first statement that good medical care could lead to population problems. According to legend, Aesculapius was so successful as a healer that Hades became depopulated; Pluto complained to Zeus, who eliminated Aesculapius with a thunderbolt. The Aesculapian temples were not so much hospitals as religious institutions where patients came on pilgrimages, hoping to be cured by a visitation of the gods; the medical historian Henry Sigerist suggests Lourdes as the closest modern parallel.

Predictably, the most common cures were of people suffering from what would now be called hysterical or psychosomatic illness-headache, insomnia, indigestion, blindness caused by emotional trauma, and so on.

The hospital in a more modern sense began in late Roman times, and coincided with the spread of Christianity across Europe. The word "hospital" is derived from the Latin hospes, meaning host or guest; the same root has given us "hotel" and "hostel." Indeed, the first hospitals were little different from hotels and hostels. Essentially they were places where the sick could rest and be fed until they recuperated or died. All hospitals were run by the Church, and most were associated with monasteries. Medicine was practiced by monks and priests.

In theory, Sigerist notes, "Christianity gave the sick man a position in society that he had never had before, a preferential position. When Christianity became the official religion of the Roman Empire, society as such became responsible for the care of the sick."

But in practice, this preferential position had its drawbacks. Conditions in the medieval hospitals varied widely. Certain of them, well financed and well managed, were famous for their humane treatment and their cheerful, spacious surroundings. But most were essentially custodial institutions to keep troublesome and infectious people off the streets. In these places, crowding, filth, and high mortality among both patients and attendants were the rule.

All this soon led to the notion that one avoided a hospital if at all possible. Wealthier-and more worldly-patients were treated in their homes by apothecaries and barber surgeons; only the traveler, the very poor, and the hopelessly ill found their way into the hospitals, and for these people it was indeed "an antechamber to the tomb."

The Renaissance and Reformation loosened the Church's stronghold on both the hospital and the conduct of medical practice. New medical schools sprang up at Salerno, Bologna, Montpellier, and Oxford; in England, Henry VIII dissolved the monastery-hospital system altogether, and a network of private, nonprofit, voluntary hospitals was started to take its place.

A medical school was associated with St. Bartholomew's in 1622; it has thus been a teaching hospital for nearly three hundred and fifty years. Among its eminent surgeons and physicians have been William Harvey, the discoverer of the circulation of the blood; Percival Pott, who first described Pott's disease, tuberculosis of the spine; the brilliant and inventive surgeon John Abernethy; and Sir James Paget, the man who described Paget's disease.

During the seventeenth century, urban London was growing enormously, yet there were only two hospitals-St. Bartholomew's and St. Thomas's. The demands made upon these two institutions gradually resulted in an important change in function. Instead of caring for all patients, they shifted their emphasis to patients who could be cured, leaving the incurables to asylums and prisons. In 1700, St. Thomas's orders stated flatly: "No incurables are to be received"-a harsh order, but one with the encouraging implication that medicine was beginning to divide its clientele into those who could be helped, and those who could not. The situation was made more humane a few years later when a wealthy merchant, Sir Thomas Guy, financed one of the first private, voluntary hospitals to care for all patients, curable or not.

By now the hospital was becoming demonstra-bly more modern in purpose, but it remained a place to be feared and shunned. George Orwell notes that "if you look at almost any literature before the latter part of the nineteenth century, you find that a hospital is popularly regarded as much the same thing as a prison, and an old-fashioned, dungeon-like prison at that. A hospital is a place of filth, torture, and death, a sort of antechamber to the tomb. No one who was not more or less destitute would have thought of going into such a place for treatment."

Under the circumstances, it is not surprising that the first American colonists were in no hurry to build hospitals.

Although there was only one physician among the original passengers on the Mayflower, generally speaking the early immigrants to Massachusetts were remarkably well educated. According to one estimate, in 1640 there was an Oxford or Cambridge graduate for every two hundred and fifty colonists. This may have been the reason why Massachusetts had the first college (Harvard, 1636), the first printing press (in Cambridge, 1639), and the first newspaper in the Colonies (Boston, 1704). Massachusetts also contributed the first medical article written and published in the New World-"A Brief Rule to Guide the Common People of New England how to order themselves and theirs in the Small-Pocks, or MeaSels." It was written by Thomas Thacher, the first minister of the Old South Church. (Not all the energies of the colonists were directed toward intellectual pursuits, however, for Massachusetts also contributed the first epidemic of syphilis in the New World, in Boston, 1646.)

Nevertheless, Boston had no general hospital for two hundred years after the landing of the Pilgrims. During this time the city had been growing rapidly-from a population of 4,500 in 1680, to 11,000 in 1720, and finally to 32,896 in 1810. By now it was clear that an almshouse was inadequate for the population, a conclusion reached some years earlier in the larger cities of Philadelphia and New York.

Thus the Reverend John Bartlett, chaplain of the overcrowded almshouse, wrote a letter in 1811 to "fifteen or twenty-five of the wealthiest and most respected citizens of Boston," urging support of a general hospital. Shortly before, two professors of the newly formed Harvard Medical School had written a similar letter. Their emphasis was slightly different, for the medical school needed a hospital for clinical teaching, and every attempt to use the existing almshouse or to build a new hospital had been blocked by the local medical society, whose members feared the encroachment of the school on the conduct of medical practice.

Through these letters run a number of recurrent themes: that a hospital is indispensable for training young doctors; that existing facilities are inadequate; that the obligations of Christian charity demand support of a hospital; and that Boston has fallen behind Philadelphia and New York.

The appeal, on many levels, was certainly successful. When fund-raising began in 1816 (it was delayed by the War of 1812), $78,802 was collected in the first three days, and donations eventually exceeded $140,000.

The State was involved to the following extent: it granted a charter to incorporate the Massachusetts General Hospital; it contributed some real estate along the banks of the Charles River; it contributed granite for construction of the building; and it supplied convict labor to build it.

The designer of the building was Charles Bulfinch, Jr., a leading architect and son of a prominent physician. With its dome, the building was an architectural marvel of its time, and was considered the most beautiful structure in Boston for many years afterward. Organizationally, too, it was quite advanced; it was patterned upon the English urban teaching hospital as exemplified by Guy's Hospital in London.

The new institution was not, however, immediately popular with Boston citizenry. The first patient appeared on September 3, 1821, but no other applied until September 20, and the hospital never ran at full census until after 1850, when massive emigration from Ireland increased the city population fourfold.

This early reluctance to use the newly founded institution is frequently attributed to experiences with earlier hospitals, such as the military hospitals of the Revolution (which Benjamin Rush said "robbed the United States of more citizens than the sword"), the pesthouses, and the almshouses.

But in fact it is perfectly understandable if one considers the state of medical science when the hospital first opened its doors.

In 1821, the concept that cleanliness could prevent infection was unknown. There was little systematic attempt to keep the hospital clean; physicians went directly from the autopsy room to the bedside without washing their hands, and surgeons operated in whatever old street clothes were considered too shabby for other purposes.

In 1821, the stethoscope was a newfangled French gadget, invented four years before by Laennec. (It was a hollow tube, designed to break into two pieces so it could be carried inside a physician's top hat.) The syringe for injection was a novelty; the clinical thermometer would not be introduced for another forty years; and X-ray diagnosis was nearly a century off.

In 1821, the average physician's list of drugs contained many substances of doubtful value, including live worms, oil of ants, snakeskins, strychnine, bile, and human perspiration. Not so long previously, Governor John Winthrop had accepted powdered unicorn horn as a valuable addition to his pharmacopoeia. And if all this seems an exaggeration, it is worth remembering that as late as 1910 some doctors at the hospital still regarded strychnine as good treatment for pneumonia.

In 1821, there was no anesthesia, and consequently few operations. The post-operative infection rate was nearly 100 per cent. Surgical mortality was close to 80 per cent. In the first full year of service, the hospital treated 115 patients. Although records from that time are lost, the mortality for the hospital as a whole in its early years was a fairly constant 10 per cent.

Clearly, the hospital has undergone an astonishing growth in size and complexity since those days. That growth generally goes unquestioned; it is a peculiarity of the American mentality that the growth of almost anything is applauded. (Consider the mindless jubilation that accompanied the growth of our population to two hundred million.) One may ask whether there are any drawbacks to the size of today's MGH, and to its current emphasis on acute, curative medicine. The question is difficult to answer.

First there is size. For both patient and physician, the sheer size of the hospital can create problems. The patient may find it cold, enormous, impersonal; the doctor whose patients or consultations are widely scattered may find himself walking as much as a quarter of a mile from bed to bed. The intimate, supportive atmosphere that is possible in a smaller hospital cannot be achieved to the same extent here.

On the other hand, a large patient population permits active research on a range of less common diseases; and the hospital serves a genuine function as a place of expert management in such illnesses. Similarly, highly technical procedures, requiring trained personnel and expensive machinery, can be supported in a large hospital, and these procedures can be carried out with a high degree of expertise. Patients who require open-heart surgery or sophisticated radiotherapy find the expensive equipment for such procedures here-and, equally important, staff that carries out such procedures daily.

As for the emphasis on curative measures directed toward established organic illness, two points can be made. First, the hospital's ability to continue to care for the patient once he has left the hospital is not as good as anyone would like. The MGH founded the first social-service department in America, in 1905, to look after such follow-up care in areas not strictly medical. These departments are now standard in most large hospitals. Similarly, the out-patient clinics are designed to provide continuity of medical care to ambulatory patients. But many patients are "lost to follow-up," to use the hospital's expression; they don't answer the social worker's calls, or they don't keep their clinic appointment Nor can they be wholly faulted in this regard, for the hospital's out-patient services are, in general, quite time-consuming for the person who wants to use them. Not only does the patient spend hours in the clinic itself, but he must take the time to travel to and from the hospital on each visit.