Overview: Medicine 1800-1899

Despite the exciting advances that took place in science and medicine in the seventeenth and eighteenth centuries, it was only in the nineteenth century that medicine itself became scientific. This was largely the result of the integration of the natural sciences into medical theory. During the eighteenth century the foundations of scientific medicine were first established. The ideas of the Enlightenment had inspired the search for rational systems of medicine, as well as practical means of preventing disease and improving human welfare. Social and medical reformers argued that scientific investigations of the abominable conditions of cities, navies, armies, and prisons, as well as the human body and pathological signs and symptoms, could improve the health and prosperity of society as a whole. Advocates of public health and preventive medicine, like Johann Peter Frank (1745-1821), sometimes urged states to adopt authoritarian methods to accomplish their goals and ideals. By studying the lives of peasants and workers, reformers hoped to make physicians and philosophers see how diseases were generated by a social system that kept whole classes of people in conditions of permanent misery.

Giovanni Battista Morgagni (1682-1771), pioneer of pathological anatomy and author of On the Seat and Cause of Disease (1761) established the existence of correlations between clinical symptoms and postmortem findings. Morgagni's research helped establish a new epoch in medical science and a new attitude toward specific diagnostic and surgical interventions. His work encouraged scientists to find ways of detecting hidden anatomical lesions in living patients. This goal was realized by the chest percussion studies of Leopold Auenbrugger (1722-1809), the invention of the stethoscope by René Laënnec (1781-1826), the introduction of increasingly sophisticated medical instruments, the establishment of "hospital medicine" and "pathological anatomy" at the Paris Hospital, the "tissue theory" of Marie François Xavier Bichat (1771-1802), the "numerical method" (clinical statistics) of Pierre Charles Alexandre Louis (1787-1872), and so forth. Although hospital reform was difficult and expensive, the hospital was transformed into the new center of medical treatment, teaching, and research. Large urban hospitals offered unprecedented opportunities for clinical experimentation, autopsies, and statistical studies. As hospitals assumed a more important role in the care of the patient, especially in growing urban areas, nursing emerged as a respectable profession for women. Gaining admission to the medical profession itself was very difficult for women, but Elizabeth Blackwell (1821-1910) and others demonstrated that women could practice medicine, establish clinics, hospitals, and medical colleges.

Although nutrition is generally regarded as a twentieth century science, the belief that health and long life depend on the regulation of food and drink is one of the most ancient and universal principles of medical philosophy. The chemical revolution of the eighteenth century challenged traditional ways of classifying foods. By the end of the nineteenth century these chemical categories were giving way to a new physiological concept of the role of food substances in the "animal economy." The modern science of nutrition grew out of efforts to understand and isolate the dietary factors that prevented deficiency diseases, but this required considerable progress in chemistry. Nevertheless, the scurvy experiments of James Lind (1716-1794) proved it was possible to prevent diseases by specific changes in diet. Lind tested possible antiscorbutics in a controlled dietary experiment and demonstrated that oranges and lemons cured scurvy. Nevertheless, lemons did not become part of standard rations in the American Navy until 1812. During the nineteenth century, the threat of infectious diseases diverted attention from dietary and degenerative diseases. But in the twentieth century, the chronic diseases, especially those that seem to be related to diet and obesity, have overshadowed the threat of infectious disease.

Perhaps the greatest medical achievement of the Age of Enlightenment was the discovery that inoculation and vaccination could prevent epidemic smallpox. Smallpox was such a dangerous and widespread threat that it was called "the most terrible of all the ministers of death." In many parts of Asia, India, Turkey, and Africa, folk healers attempted to protect people from virulent smallpox by "inoculation," that is, deliberately giving them a mild case of the disease with the aim of stimulating the body's resistance against subsequent exposures. European doctors dismissed these practices as barbaric superstitions, but during the eighteenth century increasing interest in natural "curiosities" led to closer observation of folk medicine. Smallpox inoculation gave medical practitioners and public health officials unprecedented responsibility for the control of epidemic disease. Weighing the risks and benefits of inoculation became an awesome responsibility for parents. Inoculation also paved the way for the rapid acceptance of vaccination. Edward Jenner (1749-1823) tested the folk belief that cowpox, a mild disease, provided protection against smallpox. In 1798 Jenner published an account of his experiments. Despite the medical profession's tendency to resist new ideas and methods, Jennerian vaccination spread throughout the world within a decade. Although debates about the safety and efficacy of preventive vaccines have raged ever since the first experiments on smallpox inoculation and vaccination, early in the nineteenth century some physicians predicted that vaccination would soon eradicate smallpox. In 1958 the World Health Organization (WHO) adopted a Smallpox Eradication Program that led to the end of smallpox in 1977. Public health authorities hoped that the lessons learned in the smallpox campaign would lead to global immunization programs for controlling diphtheria, whooping cough, tetanus, measles, poliomyelitis, and tuberculosis.

Historians have called malaria the most devastating disease in history. Even at the end of the twentieth century malaria is still a major public health threat in many parts of the world. Seventeenth-century scientists discovered that quinine was a specific remedy for malaria, and quinine became one of the "tools of empire" that made European exploitation and colonization of Africa and much of Asia possible. The isolation of quinine in 1820 was one of the great achievements of nineteenth-century chemistry. Some nineteenth-century scientists predicted the imminent conquest of malaria, but indifference to "tropical medicine" has proved to be as pernicious a disorder as malaria, yellow fever, and other diseases of the tropics. As the construction of the Panama Canal demonstrated, scientific knowledge could be used to bring "tropical fevers" under control, if the economic and political incentives were sufficient. At the end of the twentieth century, the central problem in tropical medicine remains the same: the impoverished nations that need medicines and vaccines cannot afford them, and the wealthy nations which can afford to develop remedies for so-called tropical diseases have little motivation to do so.

Despite considerable difficulty, nineteenth-century clinical medicine was ultimately transformed by the integration of the great discoveries of the basic sciences with the traditional foundations of medical science, that is, clinical observation and autopsy. With the development of new instruments and ways of looking at the human body and pathological signs and symptoms, specialization became a fundamental aspect of the medical profession. Throughout most of history, specialists had been regarded as little more than quacks and empiricists. Fundamental changes in ways of looking at the body followed the establishment of the cell theory by Matthias Schleiden (1804-1881) and Theodor Schwann (1810-1882), cellular pathology, by Rudolf Virchow (1821-1902), and the experimental physiology of François Magendie (1783-1855) and Claude Bernard (1813-1878). Anesthesia and antisepsis transformed the ancient art of surgery, but surgeons could not yet control shock and blood loss. Advances in therapeutics, however, would be comparatively modest until the twentieth century when antimicrobial drugs were discovered. Scientists could, however, point to innovative diagnostic tests, vaccines, antitoxins, synthetic antipyretic drugs, serum therapy, and the search for the "magic bullets" that would mimic the body's own immune responses as major achievements.

Certainly, one of the great advances of nineteenth century was the establishment of the germ theory of disease by Louis Pasteur (1822-1895), Robert Koch (1843-1910), and others. Isolating the microbial agents that caused infectious diseases and elucidating their means of transmission promised great advances in the control, prevention, and treatment of epidemic diseases. Based on the fundamentals of germ theory, Paul Ehrlich (1854-1915) established the basis of chemotherapy, and along with Ilya Metchnikoff (1845-1916), the science of immunology. The work of Ehrlich, Emil von Behring (1854-1917), and Shibasaburo Kitasato (1852-1931) led to the production of antitoxins for diphtheria, tetanus, and other diseases. Koch's discovery of the microbe that causes tuberculosis and Pasteur's development of a vaccine to treat rabies were among the most dramatic achievements by the pioneers of germ theory. One unfortunate consequence of the great achievements of modern medicine is the widespread misconception that the infectious diseases have been conquered and that the chronic, degenerative diseases are our only remaining medical problems. Understanding the complex relationships that link health, disease, demography, geography, ecology, and economics, and the differences in patterns of disease found in wealthy nations and developing nations, remains a major challenge. The emergence of new diseases, such as AIDS, in the late twentieth century demonstrates the need for a global and historic perspective in medicine and in the biomedical sciences.

LOIS N. MAGNER