With the establishment of the Roman supremacy, Rome became the great centre of medical science, and the state of knowledge in the 1st century A.D. is depicted in the treatise on medicine written by A. Cornelius Celsus. The most famous of the Roman physicians, Galen (q.v.), lived in the second century after Christ. His system was modelled upon that of Hippocrates, and he devoted special attention to the development of knowledge in connection with anatomy, physiology, and the use of drugs. The writings of Aretseus of Cappadocia, who appears to have lived at about the same time as Galen, have acquired considerable celebrity.
The Arabian writers next demand attention; though of much later date, their works present no great advance on the writings of the early centuries of the Christian era. They introduced many new drugs, and mention is for the first time made by them of small-pox and measles. Rhazes, who lived in the 10th century, and his successors, Avicenna and Averrhoe's (q.v.), were the greatest of the Arabian writers, and their-works were largely read in Europe in a Latin dress, particularly in the great schools of Salerno, Montpellier, and Bologna.
With the revival of learning, the ancient Greek and Roman writings again began to be read in their original form, and men were no longer content to study the writings of the ancients through the medium of their Arabian interpreters. There also arose at this time the system of chemical medicine which is associated with the name of Paracelsus, who lived in Germany in the 10th century. Moreover, certain great epidemics stimulated medical study in the 15th and the 16th centuries, and syphilis made its appearance in Europe.
In the 17th century came Harvey's (q.v.) great discovery of the circulation of the blood, and the commencement of the application of physical and chemical knowledge to medical science. The Spanish bark was discovered, the plague made its appearance, and in the later years of the century lived the famous Sydenham. This author, who is often called the English Hippocrates, directed attention to the importance of studying the phenomena of disease apart from preconcerted theories as to the nature of morbid processes. He invented the celebrated phrase, "epidemic constitution," and minutely described the epidemic diseases prevalent in London during a series of years. He was a great advocate of bleeding, but introduced many improvements in methods of treatment.
During the 18th century flourished the great teachers Boerhaave, Stahl, and Haller, the works of Morgagni on anatomy and of Cullen on medicine appeared, and the treatises of Fothergill on the putrid sore-throat, of Huxham on epidemic fevers, and the commentaries of Heberden were written. At the end of the century came the momentous discovery of vaccination by Jenner. Avenbruggers's work on percussion appeared in 1761, but it was not popularised until it was translated many years later by Corvisart. The method of physical diagnosis was completed by Laennec, who invented auscultation.
Some of the chief additions to knowledge made in the first half .of the 19th century have been those of Bretonneau, who described diphtheria; of Trousseau; of Richard Bright, who gives his name to Bright's disease; and of Addison, who gives his name to Addison's disease; while Graves and Stokes of Dublin should also be mentioned. In Germany Skoda developed the work of Laennec, and Rokitansky elaborated the science of pathology.
In 1821 Sir Charles Bell demonstrated the function of the anterior and posterior roots of the spinal cord, and then followed a steady advance in the knowledge of the pathology of the nervous system, which resulted in more recent years in the unravelling of the mysteries of diseases of the spinal cord by Duchenne and by Charcot. The year 1849 is remarkable for the announcement by Dr. Snow of the possibility of the conveyance of the infection of cholera by drinking water, and for the demonstration by Sir William Jenner of the difference between typhoid and typhus fevers.
The great discovery of the anaesthetic influence of ether was made shortly before the middle of the century, and soon afterwards followed the demonstration of the utility of the clinical thermometer, and then subsequently the discovery of the laryngoscope and ophthalmoscope. The advances of recent years have been made on two great lines of new departure. In the first place, there has been the growth of preventive medicine, or sanitary science, with resulting diminution of the mortality from preventable disease and the material reduction thereby effected in the general death-rate; and, secondly, the growth of the germ theory of disease, which has profoundly modified medicafscience and treatment, Davaines's discovery of the bacillus of anthrax, Pasteur's brilliant researches, and in recent times the wonderful discoveries of Koch, may be noted as conspicuous instances of the yvork which has been, and is being, done in this branch of knowledge, and which has already so greatly modified, and is probably destined still further to modify, the practice of medicine.