Theodor Billroth was one of Lister's greatest disciples. He introduced Lister's methods into continental surgery and through their use improved the treatment of wounds and opened up new fields in the surgery of the alimentary tract. He was the first to make a resection of the esophagus and pylorus and to excise the larynx. Mikulicz-Rodecki, a Pole, was Billroth's chief assistant. He was also a pioneer in Lister's practice. Specializing on the surgery of the alimentary organs, he promoted antiseptic methods and introduced the modern modes of exploring the esophagus and stomach. He was also a master in the treatment of diseases of the mouth. Felix Guyon applied Lister's system to surgical treatment of the genitourinary ailments, and became a leader in this class of surgery. Bernard Naunyn, a well-known German writer on surgery, became a leading authority on diabetes and diseases of the liver and pancreas. Jean Martin Charcot made the Salpêtrière Hospital, Paris, the greatest of the world's neurological clinics. He was also a great authority on diseases of the biliary passages and kidneys. Sir James Paget, Sir Jonathan Hutchinson, Sir William Gull, Jenner, Wilks, Spencer Wells, and Clifford Allbutt, besides doing much by their writings to advance the practice of medicine, all closely allied themselves with large hospitals, giving as much attention to the hospitals as to the treatment of disease. Modern hospitals are largely due to their pioneering work. Louis Pasteur's studies in fermentation led to the discovery of lactic-acid bacteria and this was the starting point for a number of revolutionary discoveries in bacterial diseases. Infectious diseases were placed in new categories by his work. The etiology of traumatic infectious diseases was advanced by the researches of Robert Koch (1843-1910). His work in discovering the cholera vibrio, the microorganisms of Oriental ophthalmia and his researches on the nature and treatment of tuberculosis, made his name known everywhere. His isolation of the tuberculosis germ in 1882, and that of Asiatic cholera in 1884, were leading steps toward the discovery of a great number of disease germs. Fevers, like typhus, typhoid, yellow fever, and malaria, a few generations ago, took a great annual toll of lives. The work of the men mentioned above, Lister, Pasteur, Koch, and the French physiologist, Claude Bernard, gave medical men the means of curbing the ravages of these diseases so that to-day they are incidental annoyances rather than human scourges. The germ of typhoid fever was discovered in 1880 by Eberth. The cocci of pneumonia were isolated by Frankel in 1886.